January 21, 2025
Breakdown of the Static Dielectric Screening Approximation of Coulomb Interactions in Atomically Thin Semiconductors
Amine Ben Mhenni *- ,
Dinh Van Tuan - ,
Leonard Geilen - ,
Marko M. Petrić - ,
Melike Erdi - ,
Kenji Watanabe - ,
Takashi Taniguchi - ,
Seth Ariel Tongay - ,
Kai Müller - ,
Nathan P. Wilson - ,
Jonathan J. Finley *- ,
Hanan Dery - , and
Matteo Barbone *
This publication is Open Access under the license indicated. Learn More
Coulomb interactions in atomically thin materials are remarkably sensitive to variations in the dielectric screening of the environment, which can be used to control exotic quantum many-body phases and engineer exciton potential landscapes. For decades, static or frequency-independent approximations of the dielectric response, where increased dielectric screening is predicted to cause an energy redshift of the exciton resonance, have been sufficient. These approximations were first applied to quantum wells and were more recently extended with initial success to layered transition metal dichalcogenides (TMDs). Here, we use charge-tunable exciton resonances to investigate screening effects in TMD monolayers embedded in materials with low-frequency dielectric constants ranging from 4 to more than 1000, a range of 2 orders of magnitude larger than in previous studies. In contrast to the redshift predicted by static models, we observe a blueshift of the exciton resonance exceeding 30 meV in higher dielectric constant environments. We explain our observations by introducing a dynamical screening model based on a solution to the Bethe-Salpeter equation (BSE). When dynamical effects are strong, we find that the exciton binding energy remains mostly controlled by the low-frequency dielectric response, while the exciton self-energy is dominated by the high-frequency one. Our results supplant the understanding of screening in layered materials and their heterostructures, introduce a knob to tune selected many-body effects, and reshape the framework for detecting and controlling correlated quantum many-body states and designing optoelectronic and quantum devices.
Emerging Delivery Systems for Enabling Precision Nucleic Acid Therapeutics
Xiaochun Bian - ,
Liping Zhou *- ,
Zhiwei Luo - ,
Guotao Liu - ,
Zhongci Hang - ,
Haohao Li - ,
Fengyong Li *- , and
Yongqiang Wen *
Nucleic acid therapeutics represent a highly promising treatment approach in modern medicine, treating diseases at the genetic level. However, these therapeutics face numerous challenges in practical applications, particularly regarding their stability, effectiveness, cellular uptake efficiency, and limitations in delivering them specifically to target tissues. To overcome these obstacles, researchers have developed various innovative delivery systems, including viral vectors, lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, protein carriers, exosomes, antibody oligonucleotide conjugates, and DNA nanostructure-based delivery systems. These systems enhance the therapeutic efficacy of nucleic acid drugs by improving their stability, targeting specificity, and half-life in vivo. In this review, we systematically discuss different types of nucleic acid drugs, analyze the major barriers encountered in their delivery, and summarize the current research progress in emerging delivery systems. We also highlight the latest advancements in the application of these systems for treating genetic diseases, infectious diseases, cancer, brain diseases, and wound healing. This review aims to provide a comprehensive overview of nucleic acid drug delivery systems’ current status and future directions by integrating the latest advancements in nanotechnology, biomaterials science, and gene editing technologies, emphasizing their transformative potential in precision medicine.
Low-Intensity Pulsed Ultrasound Responsive Scaffold Promotes Intramembranous and Endochondral Ossification via Ultrasonic, Thermal, and Electrical Stimulation
Wanru Jia - ,
Tianlong Wang - ,
Feng Chen *- ,
Zhiqing Liu - ,
Xiaodong Hou - ,
Wentao Cao - ,
Xinyu Zhao - ,
Bingqiang Lu - ,
Yan Hu - ,
Yijie Dong - ,
Jianqiao Zhou *- ,
Zifei Zhou *- , and
Weiwei Zhan *
Multiple physical stimuli are expected to produce a synergistic effect to promote bone tissue regeneration. Low-intensity pulsed ultrasound (LIPUS) has been clinically used in bone repair for the mechanical stimulation that it provides. In addition, LIPUS can also excite the biomaterials to generate other physical stimuli such as thermal or electrical stimuli. In this study, a scaffold based on decellularized adipose tissue (DAT) is established by incorporating polydopamine-modified multilayer black phosphorus nanosheets (pDA-mBP@DAT). Their effect on bone repair under LIPUS stimulation and the potential mechanisms are further investigated. This scaffold possesses piezoelectric properties and generates a mild thermogenic stimulus when stimulated by LIPUS. With superior properties, this scaffold is demonstrated to have good cytocompatibility in vitro and in vivo. Simultaneously, LIPUS promotes cell attachment, migration, and osteogenic differentiation in the pDA-mBP@DAT scaffold. Furthermore, the combined use of pDA-mBP@DAT and LIPUS significantly affects the regenerative effect in rat models of critical-sized calvarial defects. The possible mechanisms include promoting osteogenesis and neovascularization and activating the Piezo1. This study presents insight into speeding up bone regeneration by the synergistic combination of LIPUS and pDA-mBP@DAT scaffolds.
Interfacial Elemental Analysis of Slanted Edge-Contacted Monolayer MoS2 Transistors via Directionally Angled Etching
Chia-Chun Lin - ,
Naomi Tabudlong Paylaga - ,
Chun-Chieh Yen - ,
Yu-Hsuan Lin - ,
Kuang-Hsu Wang - ,
Kenji Watanabe - ,
Takashi Taniguchi - ,
Chi-Te Liang - ,
Shao-Yu Chen - , and
Wei-Hua Wang *
This publication is Open Access under the license indicated. Learn More
Edge contacts offer a significant advantage for enhancing the performance of semiconducting transition metal dichalcogenide (TMDC) devices by interfacing with the metallic contacts on the lateral side, which allows the encapsulation of all of the channel material. However, despite intense research, the fabrication of feasible electrical edge contacts to TMDCs to improve device performance remains a great challenge, as interfacial chemical characterization via conventional methods is lacking. A major bottleneck in explicitly understanding the chemical and electronic properties of the edge contact at the metal–two-dimensional (2D) semiconductor interface is the small cross section when characterizing nominally one-dimensional edge contacts. Here, we demonstrate a directional angled etching technique that enables the characterization of the interfacial chemistry at the metal–MoS2 junction when in an edge-contact configuration. The slanted edge structure provides a substantial cross section for elemental analysis of the edge contact by conventional X-ray photoemission spectroscopy, in which a simple chemical environment and sharp interface were revealed. Facilitated by the well-characterized contact interface, we realized slanted edge-contacted monolayer MoS2 transistors encapsulated by hexagonal boron nitride. The transport characteristics and photoluminescence of these transistors allowed us to attribute the efficient carrier injection to direct and Fowler–Nordheim tunneling, validating the distinct Au–MoS2 interface. The established method represents a viable approach to fabricating edge contacts with encapsulated 2D material devices, which is crucial for both the fundamental study of 2D materials and high-performance electronic applications.
Weak H-Bond Interface Environment for Stable Aqueous Zinc Batteries
Shuai Wang - ,
Haoran Wang - ,
Jiguo Tu - ,
Lei Huang - ,
Shenzhen Deng - ,
Bingang Xu *- , and
Lei Wei *
Hydrogen evolution reaction and Zn dendrite growth, originating from high water activity and the adverse competition between the electrochemical kinetics and mass transfer, are the main constraints for the commercial applications of the aqueous zinc-based batteries. Herein, a weak H-bond interface with a suspension electrolyte is developed by adding TiO2 nanoparticles into the electrolytes. Owing to the strong polarity of Ti–O bonds in TiO2, abundant hydroxyl functional groups are formed between the TiO2[110] active surface and aqueous environment, which can produce a weak H-bond interface by disrupting the initial H-bond networks between the water molecules, thereby accelerating the mass transfer of Zn2+ and reducing the water activity. In consequence, the Zn||Zn symmetrical cells display reversible Zn plating/stripping behaviors with a high Coulombic efficiency of 99.7% over 700 cycles. Moreover, the TiO2-based suspension strategy is also applicable to other zinc salt systems and exhibits fast plating/stripping behaviors. The suspension electrolyte enables long-term full cells, including Zn||PANI hybrid capacitors and Zn||ZnVO full batteries.
Confinement Induces Morphological and Topological Transitions in Multivesicles
Luis S. Mayorga - ,
Maria L. Mascotti - ,
Bart M. H. Bruininks - , and
Diego Masone *
The study of self-assembly in confined spaces has gained significant attention among amphiphilic superstructures and colloidal design. The additional complexity introduced by interactions between contents and their containers, along with the effects of shape and lipid mixing, makes multivesicular bodies an interesting subject of study. Despite its promising applications in biomedicine, such as drug delivery and biomimetic materials, much remains unexplored. Here we investigate the effects of confinement on vesicles with varying lipid tail lengths. We first analyze the morphological changes of single spherical vesicles undergoing dehydration, which leads to a prolate-to-oblate transition. Our findings reveal that reductions in water content induce changes of shape while minimally affecting the surface area needed to maintain the hydration layer of lipid phosphate groups. Additionally, using extensive coarse-grained molecular dynamics simulations, we explore how vesicles confined within other vesicles evolve through topological changes into unexpected structures, mainly influenced by the lipid hydrocarbon lengths. Our results highlight the interplay between confinement, curvature-induced lipid sorting, and lipid-mixing entropy, leading to exquisitely self-assembled superstructures.
Prussian Blue Nanozyme Featuring Enhanced Superoxide Dismutase-like Activity for Myocardial Ischemia Reperfusion Injury Treatment
Mengmeng Long - ,
Lintao Wang - ,
Lina Kang - ,
Dongfang Liu - ,
Tingting Long - ,
He Ding - ,
Yifan Duan - ,
Hongliang He *- ,
Biao Xu *- , and
Ning Gu *
The blood flow, when restored clinically following a myocardial infarction (MI), disrupts the physiological and metabolic equilibrium of the ischemic myocardial area, resulting in secondary damage termed myocardial ischemia-reperfusion injury (MIRI). Reactive oxygen species (ROS) generation and inflammatory reactions stand as primary culprits behind MIRI. Current strategies focusing on ROS-scavenging and anti-inflammatory actions have limited remission of MIRI. Prussian blue nanozyme (PBNz) exhibits multiple enzyme-like activities including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), which are beneficial for ROS clearance and fighting inflammation. Herein, a formulation of PBNz coated with polydextrose-sorbitol carboxymethyl ether (PBNz@PSC) was developed to enhance its efficacy, biocompatibility, and safety for the treatment of MIRI. PBNz@PSC not only showed enhanced SOD-like activity due to its polysaccharide attributes but also could passively target the damaged myocardium through the enhanced permeability and retention (EPR) effect. Both in vitro and in vivo studies have validated their excellent biocompatibility, safety, ROS-scavenging ability, and capacity to drive macrophage polarization from M1 toward M2, thereby diminishing the levels of IL-1β, IL-6, and TNF-α to combat inflammation. Consequently, PBNz@PSC can reverse ischemia reperfusion-induced myocardial injury, reduce coronary microvascular obstruction (MVO), and improve myocardial remodeling and cardiac function. Moreover, PBNz@PSC showed more pronounced therapeutic effects for MIRI than a clinical drug, sulfotanshinone IIA sodium. Notably, our findings revealed the possible mechanism of PBNz@PSC in treating MIRI, which mediated AMPK activation. In conclusion, this study presents a pioneering strategy for addressing MIRI, promising improved ischemia-reperfusion outcomes.
Radially Distributed Electron Transfer on Single-Crystalline Surface of Gold Microplates
Yingjian Li - ,
Huaxu Zhou - ,
Xiaoli Deng - ,
Cong Gao - ,
Li Shen - , and
Qianjin Chen *
Electron transfer is ubiquitous in many chemical reactions and biological phenomena; however, the spatial heterogeneities of electron transfer kinetics in electrocatalysis are so far insufficiently resolved. Measuring and understanding the localized electron transfer are crucial to deciphering the intrinsic activity of electrocatalysts and to achieving further improvements in performance. By using scanning electrochemical probe microscopy to spatially resolve redox electrochemistry across the single-crystalline surface of gold microplates, we discover an intriguing radially distributed electron transfer pattern, where the kinetics around the periphery region are significantly higher than those at the central region, regardless of the redox reaction types. In combination with atomic force microscopy-based infrared spectroscopy for synergistic interrogation of local chemical heterogeneities, we deduce that such a radial pattern of electron transfer originates from the uneven distribution of passive adlayer across the microplate surface. Subsequently, we verify that the spatial heterogeneity of electron transfer can be eliminated by removing the surface adlayer by either mild room temperature aging or oxygen plasma exposure. In addition to gaining insight into the spatial heterogeneities of electron transfer at the nanoscale, our work highlights the important effect of adsorbed organic species at nanocrystal surfaces on electrocatalysis.
Building a Better All-Solid-State Lithium-Ion Battery with Halide Solid-State Electrolyte
Chao Li - and
Yaping Du *
Since the electrochemical potential of lithium metal was systematically elaborated and measured in the early 19th century, lithium-ion batteries with liquid organic electrolyte have been a key energy storage device and successfully commercialized at the end of the 20th century. Although lithium-ion battery technology has progressed enormously in recent years, it still suffers from two core issues, intrinsic safety hazard and low energy density. Within approaches to address the core challenges, the development of all-solid-state lithium-ion batteries (ASSLBs) based on halide solid-state electrolytes (SSEs) has displayed potential for application in stationary energy storage devices and may eventually become an essential component of a future smart grid. In this Review, we categorize and summarize the current research status of halide SSEs based on different halogen anions from the perspective of halogen chemistry, upon which we summarize the different synthetic routes of halide SSEs possessing high room-temperature ionic conductivity, and compare in detail the performance of halide SSEs based on different halogen anions in terms of ionic conductivity, activation energy, electronic conductivity, interfacial contact stability, and electrochemical window and summarize the corresponding optimization strategies for each of the above-mentioned electrochemical indicators. Finally, we provide an outlook on the unresolved challenges and future opportunities of ASSLBs.
Extracellular Matrix-Inspired Dendrimer Nanogels Encapsulating Cyclophosphamide for Systemic Sclerosis Treatment
Junjie Lu - ,
Danqing Huang - ,
Rui Liu - ,
Haofang Zhu - ,
Dandan Wang *- ,
Yuanjin Zhao *- , and
Lingyun Sun *
Cyclophosphamide has a certain therapeutic effect on treating systemic sclerosis (SSc), while difficulties exist in controlling severe systematic side effects and enhancing targeting capacity. Here, inspired from the natural extracellular matrix composition, we propose a cyclophosphamide-encapsulated nanogel based on dendritic polymers polyamidoamine (PAMAM) for SSc treatment. We combine bovine serum albumin and generation 5 (G5) PAMAM dendrimers with polyphenol modification to obtain nanogels featured with antioxidant and anti-inflammatory effects. The nanogels can possess excellent biocompatibility and prevent fibroblasts from oxidative stress damage and TGF-β-mediated activation. Furthermore, in the bleomycin-induced SSc mouse model, dendrimer nanogels encapsulating cyclophosphamide also exhibit the ability to attenuate fibrosis by modulating immunity, suppressing inflammation, and reducing collagen synthesis. These findings underscore the value of this dendritic polymer nanogel in the treatment of chronic SSc, indicating its broader potential for clinical applications.
Revealing the Water Structure at Neutral and Charged Graphene/Water Interfaces through Quantum Simulations of Sum Frequency Generation Spectra
Richa Rashmi - ,
Toheeb O. Balogun - ,
Golam Azom - ,
Henry Agnew - ,
Revati Kumar *- , and
Francesco Paesani *
The structure and dynamics of water at charged graphene interfaces fundamentally influence molecular responses to electric fields with implications for applications in energy storage, catalysis, and surface chemistry. Leveraging the realism of the MB-pol data-driven many-body potential and advanced path-integral quantum dynamics, we analyze the vibrational sum frequency generation (vSFG) spectrum of graphene/water interfaces under varying surface charges. Our quantum simulations reveal a distinctive dangling OH peak in the vSFG spectrum at neutral graphene, consistent with recent experimental findings yet markedly different from those of earlier studies. As the graphene surface becomes positively charged, interfacial water molecules reorient, decreasing the intensity of the dangling OH peak as the OH groups turn away from the graphene. In contrast, water molecules orient their OH bonds toward negatively charged graphene, leading to a prominent dangling OH peak in the corresponding vSFG spectrum. This charge-induced reorganization generates a diverse range of hydrogen-bonding topologies at the interface driven by variations in the underlying electrostatic interactions. Importantly, these structural changes extend into deeper water layers, creating an unequal distribution of molecules with OH bonds pointing toward and away from the graphene sheet. This imbalance amplifies bulk spectral features, underscoring the complexity of many-body interactions that shape the molecular structure of water at charged graphene interfaces.
January 20, 2025
The Rising of Flexible Organic Electrochemical Transistors in Sensors and Intelligent Circuits
Zihan Zhu - ,
Yuncong Pang - ,
Yang Li *- ,
Yuzhe Gu - ,
Xiaotian Wang - ,
Aoxi Yu - ,
Baoguang Liu - ,
Shujuan Liu - ,
Wei Huang *- , and
Qiang Zhao *
Flexible electronic devices in biomedicine, environmental monitoring, and brain-like computing have garnered significant attention. Among these, organic electrochemical transistors (OECTs) have been spotlighted in flexible sensors and neuromorphic circuits for their low power consumption, high signal amplification, excellent biocompatibility, chemical stability, stretchability, and flexibility. However, OECTs will also face some challenges on the way to commercialized applications, including the need for improved long-term stability, enhanced performance of N-type materials, integration with existing technologies, and cost-effective manufacturing processes. This review presents the device physics of OECTs in detail, including the evaluation of their various properties and the introduction of different configurations of the aforementioned OECTs. Subsequently, the components of this device and their roles are explained in depth, and the main ways to design and fabricate flexible OECTs are summarized. Following this, we summarize and analyze the principles and applications of OECTs for electrophysiological signal sensing, chemical sensing, biosensing, and sensor arrays. In addition, the concepts of OECT-based digital and neuromorphic circuits and their applications are presented. Finally, the paper summarizes the opportunities and challenges of OECT-based flexible electronics.
Atomically Fine-Tuning Organic–Inorganic Carbon Molecular Sieve Membranes for Hydrogen Production
Leiqing Hu - ,
Won-Il Lee - ,
Kai Chen - ,
Soumyabrata Roy - ,
Kieran Fung - ,
Kim Kisslinger - ,
Erda Deng - ,
Yifu Ding - ,
Pulickel M. Ajayan - ,
Chang-Yong Nam *- , and
Haiqing Lin *
Polymeric membranes with great processability are attractive for the H2/CO2 separation required for hydrogen production from renewable biomass with carbon capture for utilization and sequestration. However, it remains elusive to engineer polymer architectures to obtain desired sub-3.3 Å ultramicropores to efficiently sieve H2 from CO2. Herein, we demonstrate a scalable way of carbonizing polybenzimidazole (PBI) at low temperatures, followed by vapor phase infiltration (VPI) to atomically narrow ultramicropores throughout the films, forming hybrid organic–inorganic carbon molecular sieves (CMSs). One VPI cycle (100 s) for the PBI carbonized at 500 °C remarkably increases H2/CO2 selectivity from 9.6 to 83 at 100 °C, surpassing Robeson’s upper bound. The CMS demonstrates a stable H2/CO2 separation performance when challenged with simulated syngas streams and can be fabricated into thin-film composite membranes, outperforming state-of-the-art membranes. The scalable approach can be ubiquitous to molecularly fine-tune ultramicropores of leading polymeric membranes to further improve their size-sieving ability and thus separation efficiency.
Core–Satellite Nanoassembly Overcomes Spatial Heterogeneity of Dendric Cell Distribution in Pancreatic Tumors for Effective Chemoimmunotherapy
Gengjia Chen - ,
Bo Li - ,
Tan Li - ,
Minzhao Lin - ,
Huihai Zhong - ,
Xiaoxue Xie - ,
Qiaoyun Zhang - ,
Qi Chen - ,
Xiaochun Meng *- ,
Zecong Xiao *- , and
Xintao Shuai *
Pancreatic cancer therapies such as chemotherapy and immunotherapy are hindered by the dense extracellular matrix known as physical barriers, leading to heterogeneity impeding the effective penetration of chemotherapeutic agents and activation of antitumor immune responses. To address this challenge, we developed a hybrid nanoassembly with a distinct core–satellite-like heterostructure, PLAF@P/T-PD, which is responsive to both internal pH/redox and external ultrasound stimulations. This heterostructural nanoassembly features a polymersome core encapsulating an ultrasound contrast agent perfluoropentane and a chemotherapeutic agent Taxol (PLAF@P/T) electrostatically coated with satellite-like polyplexes carrying an immune agonist dsDNA (PD), which brings about synergistic functions inside the pancreatic tumor. The PLAF@P/T core functions as an enhancer for intratumor delivery through size enlargement and charge conversion in response to reactive oxygen species (ROS) and low pH, which triggers polyplex release and enables ultrasound-assisted tumor-penetrating Taxol delivery. Meanwhile, the released cationic polyplexes function as nucleic nanomedicine preferentially engulfed by peripheral dendritic cells (DCs) for immune modulation. Animal studies in mouse orthotopic pancreatic tumor model demonstrated exceptional therapeutic efficacy against both primary and metastatic tumors, which underlines the potential of this heterostructural nanoplatform for overcoming the therapeutic challenges associated with the heterogeneous physical barrier hindering intratumor drug delivery in pancreatic cancer treatment.
Electrical Control of Photoluminescence in 2D Semiconductors Coupled to Plasmonic Lattices
Antti J. Moilanen *- ,
Moritz Cavigelli - ,
Takashi Taniguchi - ,
Kenji Watanabe - , and
Lukas Novotny
This publication is Open Access under the license indicated. Learn More
Integrating two-dimensional (2D) semiconductors into nanophotonic structures provides a versatile platform for advanced optoelectronic devices. A key challenge in realizing these systems is to achieve control over light emission from these materials. In this work, we demonstrate the modulation of photoluminescence (PL) in transition metal dichalcogenides (TMDs) coupled to surface lattice resonances in metal nanoparticle arrays. We show that both the intensity and the emission angle of light can be tuned by adjusting the lattice parameters. By applying gate electrodes to electrostatically dope the TMDs coupled to plasmonic lattices, we achieve PL intensity switching over 2 orders of magnitude with a low applied voltage. Our results represent an important step toward electrically powered and electrically tunable light sources based on 2D semiconductors.
January 19, 2025
Identifying Carbon–Carbon Triple Bonds from Double Bonds via Single-Molecule Conductance
Sifan You - ,
Yixuan Gao - ,
Yanning Tang - ,
Chaojie Xu - ,
Jing He - ,
Xuechao Li - ,
Haiming Zhang - ,
Shixuan Du *- , and
Lifeng Chi *
Molecular-scale electronics focuses on understanding and utilizing charge transport through individual molecules. A key issue is the charge transport capability of a single molecule characterized by current decay. We visualize the on-site formation of conjugated polymers with varying carbon–carbon bond orders by using scanning tunneling microscopy and noncontact atomic force microscopy. Although carbon–carbon double bonds and triple bonds exhibit similar electronic characteristics, single-molecule conductance measurements reveal distinct features based on different levels of conjugation. These findings, supported by density functional theory calculations, indicate that a higher bond order results in greater electron density and more symmetric molecular orbitals, leading to larger transmission rates and more rigid frontier orbitals. Consequently, this contributes to a higher conductance and a lower decay constant. These findings enhance the understanding of bond orders in molecular electronics and should facilitate the development of single-molecule devices and the applications of nanoscale circuitry.
A Deep Insight into the Microscopic Dynamics of the Electrode–Electrolyte Interface under Extreme Operating Conditions
Rui Yuan - ,
Handong Jiao *- ,
Xueyan Du - ,
Leyang Li - ,
Qiang Liu - , and
Shuqiang Jiao *
Understanding the interfacial dynamics during operation is critical for electrochemistry to make great advancements. However, breakthroughs on this topic under extreme conditions are very scarce. Here, as an example, we employ operando Raman spectroscopy to decode the interfacial dynamics of titanium electrolysis using a tailored instrument. Direct spectral evidence not only confirms the two-step reduction pathway and the key intermediate (TiF52–) in molten fluorides with high-temperature and strong-corrosion conditions but also unravels the origins of the undesirable shuttling effect of TiF52–, which are the sluggish reduction kinetics and outward diffusion behavior of TiF52–. Moreover, an insightful atomic scenario of the electric double layer (EDL) under varied potentials has been established. These quantitative understandings guide us to design economical-feasible regulation protocols─the rational combination of a high-concentration, low-valence Ti-ion electrolyte with appropriate applied potential. Impressively, the current efficiency is greatly promoted from 27.7 to 81.8% using our proposed protocols. Finally, this work also demonstrates a bottom-up technological research paradigm for extreme electrochemistry based on mechanism insights rather than phenomenological findings, which will accelerate the advancement of extreme electrochemistry.
High-Throughput Screening Strategy and Metal–Organic Framework-Based Multifunctional Controlled-Release Nanomaterial for Osteoarthritis Therapy
Yu Chen - ,
Yekai Zhang - ,
Chenyu Wu - ,
Xiaoying Zhao - ,
Hanwen Zhang - ,
Chenchao Li - ,
Yuxin Deng - ,
Liaojun Sun - ,
Yifei Zhou *- , and
Xiaolei Zhang *
Osteoarthritis (OA) is a prevalent degenerative disease that lacks effective therapy. Oxidative stress is one of the major factors contributing to OA; however, treatments targeting oxidative stress are still lacking. In the current study, we established an oxidative stress-induced cell death model in chondrocytes in vitro and screened drugs that may suppress oxidative stress-induced cell death. Ethyl gallate (EG) was identified as the most potent drug against oxidative stress-induced cell death out of more than 600 drugs in the natural product library. Application of drugs without an appropriate delivery system for OA therapy may have drawbacks such as low bioavailability, short action time, and poor efficacy. Herein, poly-His6-zinc assembly (PZA), a pH-responsive metal–organic framework (MOF) loaded with EG (EG@PZA) was designed for OA therapy. It was demonstrated that EG@PZA may have the lysosome escape property, which dramatically increases the utilization of EG. Furthermore, EG@PZA showed enhanced release capability of EG in the acidic microenvironment. In vitro and in vivo studies demonstrated that EG@PZA effectively suppresses oxidative stress-induced extracellular matrix degradation, ferroptosis, and senescence in chondrocytes and also ameliorates OA in the destabilization of the medial meniscus (DMM) mouse model in vivo. Together, the current study showed that EG@PZA may become a potential controlled-release nanomaterial for effective OA therapy.
January 18, 2025
Nanoscale Viscometry Reveals an Inherent Mucus Defect in Cystic Fibrosis
Olga Ponomarchuk - ,
Francis Boudreault - ,
Ignacy Gryczynski - ,
Bong Lee - ,
Sergei V. Dzyuba - ,
Rafal Fudala - ,
Zygmunt Gryczynski *- ,
John W. Hanrahan - , and
Ryszard Grygorczyk *
The abnormally viscous and thick mucus is a hallmark of cystic fibrosis (CF). How the mutated CF gene causes abnormal mucus remains an unanswered question of paramount interest. Mucus is produced by the hydration of gel-forming mucin macromolecules that are stored in intracellular granules prior to release. Current understanding of mucin/mucus structure before and after secretion remains limited, and contradictory models exist. Here, we used a molecular viscometer and fluorescence lifetime imaging of human bronchoepithelial cells (Normal and CF) to measure nanometer-scale viscosity. We found significantly elevated intraluminal nanoviscosity in a population of CF mucin granules, indicating an intrinsic, presecretory mucin defect. Nanoviscosity influences protein conformational dynamics and function. Its elevation along the protein secretory pathway could arise from molecular overcrowding, impacting mucin’s post-translational processing, hydration, and mucus rheology after release. The nanoviscosity of secreted CF mucus was elevated compared to that of non-CF. Interestingly, it was higher after release than in granules. Validation experiments indicate that reduced mobility of water hydrating mucin macromolecules may contribute to the high nanoviscosity in mucus and mucin granules. This suggests that mucins have a weakly ordered state in granules but adopt a highly ordered, nematic crystalline structure when secreted. This challenges the traditional view of mucus as a porous agarose-like gel and suggests an alternative model for mucin organization before and after secretion. Our study also indicates that endoplasmic reticulum stress due to molecular overcrowding could contribute to mucus pathogenesis in CF cells. It encourages the development of therapeutics that target presecretory mechanisms in CF and other muco-obstructive lung diseases.
Efficient Nitrate to Ammonia Conversion on Bifunctional IrCu4 Alloy Nanoparticles
Ning He - ,
Zhi Yuan - ,
Chao Wu - ,
Shibo Xi - ,
Jingjing Xiong - ,
Yucong Huang - ,
Guanwu Lian - ,
Zefan Du - ,
Laihao Liu - ,
Dawei Wu - ,
Zhongxin Chen *- ,
Wenguang Tu *- ,
Zhigang Zou - , and
Shuk-Yin Tong *
Electrochemical nitrate reduction (NO3RR) to ammonia presents a promising alternative strategy to the traditional Haber–Bosch process. However, the competitive hydrogen evolution reaction (HER) reduces the Faradaic efficiency toward ammonia, while the oxygen evolution reaction (OER) increases the energy consumption. This study designs IrCu4 alloy nanoparticles as a bifunctional catalyst to achieve efficient NO3RR and OER while suppressing the unwanted HER. This is achieved by operating the NO3RR at positive potentials using the IrCu4 catalyst, which allows a Faradaic efficiency of 93.6% for NO3RR. When applied to OER catalysis, the IrCu4 alloy also shows excellent results, with a relatively low overpotential of 260 mV at 10 mA cm–2. Stable ammonia production can be achieved for 50 h in a 16 cm2 flow electrolyzer in simulated working conditions. Our research provides a pathway for optimizing NO3RR through bifunctional catalysts in a tandem approach.
January 17, 2025
Mapping the Energy Carrier Diffusion Tensor in Perovskite Semiconductors
Roberto Brenes - ,
Dane W. deQuilettes *- ,
Richard Swartwout - ,
Abdullah Y. Alsalloum - ,
Osman M. Bakr - , and
Vladimir Bulović *
Understanding energy transport in semiconductors is critical for the design of electronic and optoelectronic devices. Semiconductor material properties, such as charge carrier mobility or diffusion length, are commonly measured in bulk crystals and determined using models that describe transport behavior in homogeneous media, where structural boundary effects are minimal. However, most emerging semiconductors exhibit nano- and microscale heterogeneity. Therefore, experimental techniques with high spatial resolution paired with models that capture anisotropy and domain boundary behavior are needed. We develop a diffusion tensor-based framework to analyze experimental photoluminescence (PL) diffusion maps accounting for material nano- and microstructure. Specifically, we quantify both carrier transport and recombination in single crystal and polycrystalline lead halide perovskites by globally fitting diffusion maps with spatial, temporal, and PL intensity data. We reveal a 29% difference in principal diffusion coefficients and alignment between electronically coupled grains for CH3NH3PbI3 polycrystalline films. This framework allows for understanding and optimizing anisotropic energy transport in heterogeneous materials.
Transforming Medicine: Cutting-Edge Applications of Nanoscale Materials in Drug Delivery
Rumiana Tenchov - ,
Kevin J. Hughes - ,
Magesh Ganesan - ,
Kavita A. Iyer - ,
Krittika Ralhan - ,
Leilani M. Lotti Diaz - ,
Robert E. Bird - ,
Julian M. Ivanov - , and
Qiongqiong Angela Zhou *
This publication is Open Access under the license indicated. Learn More
Since their inception in the early 1960s, the development and use of nanoscale materials have progressed tremendously, and their roles in diverse fields ranging from human health to energy and electronics are undeniable. The application of nanotechnology inventions has revolutionized many aspects of everyday life including various medical applications and specifically drug delivery systems, maximizing the therapeutic efficacy of the contained drugs by means of bioavailability enhancement or minimization of adverse effects. In this review, we utilize the CAS Content Collection, a vast repository of scientific information extracted from journal and patent publications, to analyze trends in nanoscience research relevant to drug delivery in an effort to provide a comprehensive and detailed picture of the use of nanotechnology in this field. We examine the publication landscape in the area to provide insights into current knowledge advances and developments. We review the major classes of nanosized drug delivery systems, their delivery routes, and targeted diseases. We outline the most discussed concepts and assess the advantages of various nanocarriers. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding nanosized drug delivery systems, to outline challenges, and to evaluate growth opportunities. The merit of the review stems from the extensive, wide-ranging coverage of the most up-to-date scientific information, allowing unmatched breadth of landscape analysis and in-depth insights.
Smart Vascular Grafts with Integrated Flow Biosensors for Hemodynamic Real-Time Monitoring and Vascular Healthcare
Zhiqiang Ma *- ,
Jing Zhang *- ,
Shangjie Zou - ,
Ke Huang - ,
Wei Li - ,
Mohamed Elhousseini Hilal - ,
Mingze Zhu - ,
Yatian Fu - , and
Bee Luan Khoo *
Real-time monitoring of hemodynamics is crucial for diagnosing disorders within implanted vascular grafts and facilitating timely treatment. Integrating vascular grafts with advanced flexible electronics offers a promising approach to developing smart vascular grafts (SVGs) capable of continuous hemodynamic monitoring. However, most existing SVG devices encounter significant challenges in practical applications, particularly regarding biomechanical compatibility and the effective evaluation of vascular status. Here, we present a state-of-the-art SVG device seamlessly integrated with flow biosensors constructed by encapsulating patterned porous graphene within biocompatible polymers. The innovative use of porous graphene imparts the SVG with exceptional mechanical sensing performance, featuring a low strain detection limit of 0.0034% and dynamic stability exceeding 32,400 cycles, thus enabling precise hemodynamic perception. This high sensitivity allows the SVG to accurately diagnose vascular disorders, such as blockage degree and position, by collecting hemodynamic data from an artificial artery model. In vitro thrombi (blood clot) diagnostics, treatment simulation experiments, and in vivo tests using a rabbit model strongly validate the SVG’s outstanding and reliable performance in vascular healthcare. We have also developed a stand-alone and wireless system, demonstrating its capability for remote monitoring and managing vascular health. Our pioneering SVG system showcases great potential in vascular healthcare for precise hemodynamic monitoring of disorders, timely diagnostics, and even drug screening.
Understanding the Mechanism of Electrochemical CO2 Capture by Supercapacitive Swing Adsorption
Grace Mapstone - ,
Tim M. Kamsma - ,
Zhen Xu - ,
Penelope K. Jones - ,
Alpha A. Lee - ,
Israel Temprano - ,
James Lee - ,
Michael F. L. De Volder - , and
Alexander C. Forse *
This publication is Open Access under the license indicated. Learn More
Carbon dioxide capture underpins an important range of technologies that can help to mitigate climate change. Improved carbon capture technologies that are driven by electrochemistry are under active development, and it was recently found that supercapacitor energy storage devices can reversibly capture and release carbon dioxide. So-called supercapacitive swing adsorption (SSA) has several advantages over traditional carbon dioxide capture technologies such as lower energy consumption and the use of nontoxic materials. However, the mechanism for the capture of CO2 in these devices is poorly understood, making it challenging to design improved systems. Here, the mechanism of SSA is investigated via finite-element modeling with COMSOL of aqueous continuum transport equations, coupled to the CO2 to bicarbonate reaction. This simple computational model reproduces the key experimental observations and shows that charging leads to bicarbonate depletion (or accumulation) in the electrodes, driving CO2 capture (or release) at the gas-exposed electrode. This suggests that relevant aspects of the mechanism are captured without excluding other mechanisms that might be at play in parallel as well. At very low charging currents, both experiments and modeling reveal a decrease in the amount of carbon dioxide captured, suggesting the presence of competing processes at the two electrodes, and that SSA is an inherently kinetic phenomenon. This study highlights the importance of the operating conditions of these devices and may aid their development in the future.
Tuning Dual Catalytic Active Sites of Pt Single Atoms Paired with High-Entropy Alloy Nanoparticles for Advanced Li-O2 Batteries
Lei Li - ,
Minghao Hua - ,
Jiafeng Li - ,
Peng Zhang - ,
Yingjian Nie - ,
Peng Wang *- ,
Xiaohang Lin - ,
Zhiwei Zhang *- ,
Rutao Wang - ,
Xiaoli Ge *- ,
Yuguang C. Li *- , and
Longwei Yin *
To achieve a long cycle life and high-capacity performance for Li-O2 batteries, it is critical to rationally modulate the formation and decomposition pathway of the discharge product Li2O2. Herein, we designed a highly efficient catalyst containing dual catalytic active sites of Pt single atoms (PtSAs) paired with high-entropy alloy (HEA) nanoparticles for oxygen reduction reaction (ORR) in Li-O2 batteries. HEA is designed with a moderate d-band center to enhance the surface adsorbed LiO2 intermediate (LiO2(ads)), while PtSAs active sites exhibit weak adsorption energy and promote the soluble LiO2 pathway (LiO2(sol)). An optimal ratio between LiO2(ads) and LiO2(sol) pathway was realized to modulate PtSAs and HEA active sites via regulating the etching conditions in the dealloying synthesis process for obtaining high-performance Li-O2 batteries. The ORR kinetics are accelerated, and the parasitic reactions are restrained in the Li-O2 batteries. As a result, Li-O2 batteries based on the HEA@Pt-PtSAs catalyst demonstrate an ultralow overpotential (0.3 V) and ultralong cycling performance of 470 cycles at 1000 mA g–1. The insights into the synthetic strategies and the importance of balancing the ORR pathways will offer guidance for devising multisite synergistic catalysts to accelerate redox-reaction kinetics for Li-O2 batteries.
PEGylated Ultrasmall Iron Oxide Nanoparticles as MRI Contrast Agents for Vascular Imaging and Real-Time Monitoring
Kuan Lu - ,
Ruru Zhang - ,
Hongzhao Wang - ,
Cang Li - ,
Zhe Yang - ,
Keyang Xu - ,
Xiaoyi Cao - ,
Ning Wang - ,
Wu Cai *- ,
Jianfeng Zeng *- , and
Mingyuan Gao *
Accurate imaging evaluations of pre- and post-treatment of cardiovascular diseases are pivotal for effective clinical interventions and improved patient outcomes. However, current imaging methods lack real-time monitoring capabilities with a high contrast and resolution during treatments. This study introduces PEGylated ultrasmall iron oxide nanoparticles (PUSIONPs), which have undergone comprehensive safety evaluations, boasting an r1 value of 6.31 mM–1 s–1, for contrast-enhanced magnetic resonance angiography (MRA). Systematic comparisons against common clinical methods in rabbits reveal that PUSIONPs-enhanced MRA exhibited improved vascular contrast, clearer vascular boundaries, and superior vessel resolution. Moreover, owing to their nanosize, PUSIONPs demonstrate significantly prolonged blood circulation compared to small molecular contrast agents such as Magnevist and Ultravist. This extended circulation enables captivating real-time monitoring of thrombolysis treatment for up to 4 h in rabbit models postsingle contrast agent injection. Additionally, in larger animal models such as beagles and Bama minipigs, PUSIONPs-enhanced MRA also showcases superior contrast effects, boundary delineation, and microvessel visualization, underscoring their potential to transform cardiovascular imaging, particularly in real-time monitoring and high-resolution visualization during treatment processes.
Lactobacillus-Loaded Easily Injectable Hydrogel Promotes Endometrial Repair via Long-Term Retention and Microenvironment Modulation
Guoqing Fan - ,
Yuheng Lu - ,
Yubin Li - ,
Jian Zhang - ,
Yuanbin Wang - ,
Pingyin Lee - ,
Canquan Zhou - ,
Rongkang Huang *- ,
Binghua Ma *- , and
Yuan Yuan *
Regeneration of the injured endometrium, particularly the functional layer, is crucial for the prevention of uterine infertility. At present, clinical treatment using sodium hyaluronate hydrogel injection is limited by its relatively low fluidity, short-term retention, and insufficient bioactive ingredients, so it is necessary to develop an advanced healing-promoting hydrogel. The modulation of the microenvironment by Lactobacillus presents a bioactive component that can facilitate the regeneration of the functional layer. Our study introduces a multifunctional Lactobacillus-loaded poly(N-isopropylacrylamide)-grafted bacterial cellulose (BC-g-PN@L) hydrogel designed with superior injectability and in situ stability. At 25 °C (room temperature), a uniform distribution is achieved with a low injection pressure of only 7.90 kPa. At 37 °C (body temperature), the BC-g-PN@L hydrogel forms a robust three-dimensional nanonetwork, providing space and substance exchange channels for Lactobacillus to maintain its viability and bioactivity. Enhanced by the hydrophobic isopropyl groups in poly(N-isopropylacrylamide) side chains and the rigid bacterial cellulose substrates, the BC-g-PN@L hydrogel exhibits prolonged retention properties in the uterine cavity, persisting for over 21 days. These attributes endow the BC-g-PN@L hydrogel with versatile pro-healing capacity and microenvironment modulation in a rat model of endometrial injury. Our BC-g-PN@L hydrogel promotes the development of advanced injectable hydrogels to facilitate both histological and functional repair of the injured endometrium.
Strong and Fireproof Regenerated Wood via a Combined Phosphorylation-Surface Nanofibrillation and Ionic Cross-Linking Strategy
Wen-Bin Sun - ,
Zi-Meng Han - ,
Xiao-Han Luo - ,
Huai-Bin Yang - ,
Zhao-Xiang Liu - ,
De-Han Li - ,
Kun-Peng Yang - ,
Qing-Fang Guan *- , and
Shu-Hong Yu *
To reduce the environmental impact of plastics, an increasing number of high-performance sustainable materials have emerged. Among them, wood-based high-performance structural materials have gained growing attention due to their outstanding mechanical and thermal properties. Here, we introduce phosphate groups onto the wood veneers for surface nanofibrillation, effectively altering both the molecular structure and surface morphology of wood, which enhances the interactions between wood veneers and endows the wood with excellent fire resistance properties. With these phosphorylated wood-based building blocks, “chemical welding” structural materials (CWSMs) obtained through chemical cross-linking exhibit excellent mechanical properties. The flexural strength of CWSM reaches 225 MPa, and the modulus reaches 16 GPa, surpassing those of various types of natural wood. At the same time, phosphorylation has endowed CWSM with excellent fire resistance, with a limiting oxygen index reaching 49%, making it completely noncombustible. More importantly, as a biomass-based structural material, CWSM exhibits mechanical, thermal, and fire resistance properties and degradability far superior to those of traditional petroleum-based plastics, making it an ideal candidate for plastic replacement.
Biofluid-Permeable and Erosion-Resistant Wireless Neural-Electronic Interfaces for Neurohomeostasis Modulation
Zhidong Wei - ,
Fei Jin - ,
Tong Li - ,
Yuyuan He - ,
Lili Qian - ,
Juan Ma - ,
Tao Yuan - ,
Xin Yu - ,
Weiying Zheng - ,
Negar Javanmardi - ,
Esteban Pena-Pitrach - ,
Ting Wang *- ,
Jianda Xu *- , and
Zhang-Qi Feng *
Neural-electronic interfaces through delivering electroceuticals to lesions and modulating pathological endogenous electrical environments offer exciting opportunities to treat drug-refractory neurological disorders. Such an interface should ideally be compatible with the neural tissue and aggressive biofluid environment. Unfortunately, no interface specifically designed for the biofluid environments is available so far; instead, simply stacking an encapsulation layer on silicon-based substrates makes them susceptible to biofluid leakage, device malfunction, and foreign-body reactions. Here, we developed a biofluid-permeable and erosion-resistant wireless neural-electronic interface (BNEI) that is composed of a flexible 3D interconnected poly(l-lactide) fibrous network with a dense and axially aligned piezoelectrical molecular chain arrangement architecture. The organized molecular chain structure enhances the tortuous pathway and longitudinal piezoelectric coefficient of poly(l-lactide) fibers, improves their water barrier properties, and enables efficient conversion of low-intensity acoustic vibrations transmitted in biofluids into electrical signals, achieving long-term stable and wireless neuromodulation. A 3-month clinical trial demonstrated that the BNEI can effectively accelerate the pathological cascade in peripheral neuropathy for nerve regeneration and transcranially modulate cerebellar–cerebral circuit dynamics, suppressing seizures in temporal lobe epilepsy. The BNEI can be a clinically scalable approach for wireless neuromodulation that is broadly applicable to the modulation of neurohomeostasis in both the peripheral and central nervous systems.
Targeted Modulation of the Meningeal Lymphatic Reverse Pathway for Immunotherapy of Breast Cancer Brain Metastases
Yanfeng Dai - ,
Xiang Yu - ,
Yifan Zhao - ,
Jianshuang Wei - ,
Dong Lin - ,
Jialu Wang - ,
Ren Zhang - ,
Xuenan Yuan - ,
Sanmu Li - ,
Songlin Huang - ,
Qian Liu *- , and
Zhihong Zhang *
Treatment of tumor brain metastases remains challenging due to the ineffectiveness of drugs in crossing the blood–brain barrier (BBB). Here, we proposed a potential strategy to target and modulate the meningeal lymphatic system for immunotherapy of breast cancer brain metastases (BCBM) through peripheral administration. CT/fluorescence dual-modality imaging demonstrated that the phospholipid nanoprobe (α-PLNPs) through intracisternal magna injection effectively labeled and long-range tracked the meningeal lymphatic pathway from meningeal lymphatic vessels (MLVs) to periphery drainage cervical lymph nodes (CLNs). Interestingly, the reverse pathway from CLNs to MLVs was also successfully labeled with α-PLNPs through cervical subcutaneous injection, facilitating the noninvasive delivery of immunomodulators to the meningeal lymphatics. Given this, we used melittin-carrying α-M-PLNPs to trigger the modulation of the meningeal lymphatic reverse pathway, which effectively prevents BCBM and prolongs the survival of mice through activating the antigen-presenting cells in the CLNs and promoting the migration of CD8+ T cells into the metastatic brain tumors. This study highlights the potential of the meningeal lymphatic reverse pathway for the immunotherapy of BCBM, which holds great promise for central nervous system disease therapy without the need for drug delivery via BBB.
Complex Core–Shell Architectures through Spatially Organized Nano-Assemblies
Xiangyu Jiang - ,
Bo Jiang - ,
Manrui Mu - ,
Tongyi Wang - ,
Shi Sun - ,
Jiaxin Xu - ,
Shutao Wang - ,
Yan Zhou - ,
Jun Zhang - , and
Wenle Li *
Core–shell structures demonstrate superior capability in customizing properties across multiple scales, offering valuable potential in catalysis, medicine, and performance materials. Integrating functional nanoparticles in a spatially controlled manner is particularly appealing for developing sophisticated architectures that support heterogeneous characteristics and tandem reactions. However, creating such complex structures with site-specific features remains challenging due to the dynamic microenvironment during the shell-forming process, which considerably impacts colloidal particle assembly. Here, we describe a method to spatially deploy nanoscale assemblies within microscale structures comprising a dense shell and a liquid core through colloidal surface decoration coupled with emulsion-based synthesis. Exploiting a spectrum of nanoparticles grafted with incrementally varying densities of organic ligands, we reveal that nanofeatures can be selectively sculpted onto the shell exterior, within the shell wall, and on the interior surface. The versatility of this mechanism is validated by systematically arranging nanoparticles with various compositions, shapes, and dimensions. Spatially integrated nanotitania endows the core–shell structures with localized photocatalytic abilities. Additionally, distinctive surface modifications enable the simultaneous yet independent implantation of diverse nanoparticles, yielding intricate architectures with programmable functions. This generalizable approach showcases a synthetic strategy to attain structural complexity and functional sophistication reminiscent of those of biological systems in nature.
Biomimetic Confined Assembly of Plasmonic CuS from Electronic Waste for Rapid Photothermal Disinfection
Zewei Hao - ,
Jingyu Sun - ,
Jiabin Chen *- ,
Yinchuan Yang - ,
Xiaoqi Sun - ,
Ruicheng Ji - ,
Qipeng Zhao - ,
Xuefei Zhou - ,
Hongbo Zeng - , and
Yalei Zhang *
Photothermal disinfection (PTD) offers promising potential for water purification due to its sustainable and broad-spectrum bactericidal properties, although it is hindered by slow charge separation in photosensitizers. Herein, we present a plasma-mediated PTD technique utilizing an efficient localized heating effect induced by incident light at specific wavelengths for rapid bacterial inactivation. A metallic CuS photosensitizer, derived from electronic waste through a biomimetic transmembrane confined-assembled strategy, facilitates collective and coherent oscillation of free electrons around Cu atoms in the near-infrared range. The resulting plasmon resonance effect generates abundant high-energy hot carriers, further enhancing the separation efficiency of carriers generated by plasmon-induced intrinsic excitation. The nonradiative dissipation of these carriers triggers a significant localized heating effect in water matrices, leading to comprehensive PTD performance against E. coli and B. subtilis. This study highlights the role of the plasmonic heating effect from waste-derived photosensitizers in enhancing PTD performance, inspiring the development of advanced water disinfection technologies.
January 16, 2025
Two-Dimensional Tantalum Carbo-Selenide for Hydrogen Evolution
Elham Loni - ,
Ahmad Majed - ,
Shengjie Zhang - ,
Hari H. S. Thangavelu - ,
Chaochao Dun - ,
Anika Tabassum - ,
Karamullah Eisawi - ,
Jeffrey J. Urban - ,
Per O. Å. Persson - ,
Matthew M. Montemore - , and
Michael Naguib *
This publication is Open Access under the license indicated. Learn More
Herein, we report the synthesis of two-dimensional Ta2Se2C (2D-Ta2Se2C) nanosheets using electrochemical lithiation in multilayer Ta2Se2C followed by sonication in deionized water. Multilayer Ta2Se2C was obtained via solid-state synthesis of FexTa2Se2C followed by chemical etching of Fe. 2D-Ta2Se2C exhibited promising electrocatalytic activity for the hydrogen evolution reaction from water compared to multilayer Ta2Se2C and 2D-TaSe2. 2D-Ta2Se2C showed an overpotential at 10 mA·cm–2 (η10) of 264 mV, a Tafel slope of 91 mV·dec–1, and an electrochemically active surface area of 17.61 mECSA2·gcatalyst–1. The high performance could be attributed to the large surface area of single sheets which hence maximizes the number of exposed catalytic sites and increased density of vacancies, observed with transmission electron microscopy, during synthesis and processing.
Bacterial Nanovesicles as Interkingdom Signaling Moieties Mediating Pain Hypersensitivity
Sameh Almousa - ,
Susy Kim - ,
Ashish Kumar - ,
Yixin Su - ,
Sangeeta Singh - ,
Shalini Mishra - ,
Miriam M. Fonseca - ,
Hilal A. Rather - ,
E. Alfonso Romero-Sandoval - ,
Fang-Chi Hsu - ,
Rakesh Singh - ,
Hariom Yadav - ,
Santosh Mishra - , and
Gagan Deep *
Gut dysbiosis contributes to multiple pathologies, yet the mechanisms of the gut microbiota-mediated influence on systemic and distant responses remain largely elusive. This study aimed to identify the role of nanosized bacterial extracellular vesicles (bEVs) in mediating allodynia, i.e., pain hypersensitivity, in a diet-induced obesity (DIO) gut dysbiosis model. bEVs were enriched from the feces of lean (bEVLean) and DIO (bEVDIO) mice by an approach combining ultracentrifugation and immunoprecipitation and then extensively analyzed for purity and bacterial characteristics. Next, bEVs were injected, either intraplantarly or intravenously, in mice to assess pain sensitivity. Fluorescence-labeled bEVs were injected in mice by enema to assess biodistribution. The effect of bEV on immune cells and inflammation was analyzed by array, immunophenotyping, microscopy, NF-κB activation, and cellular uptake assays. Results showed that bEVDIO administration in wild-type mice replicated the allodynia phenotype observed in DIO mice for both mechanical and thermal stimuli. Importantly, this effect was compromised in TRPA1/TRPV1 double-knockout mice. Biodistribution analyses showed bEV entry into systemic circulation with subsequent localization at distant sites. Multiple analyses revealed that bEVDIO exposure incited systemic inflammation, primarily through modulating the innate immune system. This inflammatory mechanism involved LPS on the bEV surface, activating TLR2- and TLR4-related pathways, as confirmed using TLR2 and TLR4 inhibitors and shaving bEV surface proteins. Interestingly, the enhanced cellular uptake of bEVDIO was contingent on interactions involving LPS and proteins on bEVs and TLR2/TLR4 on monocytes. These findings illuminate the hitherto unexplored role of bEV as pivotal mediators of allodynia and inflammation linked to gut dysbiosis.
Personalized Nanovaccine Based on STING-Activating Nanocarrier for Robust Cancer Immunotherapy
Yongjuan Li - ,
Ya Dong - ,
Danyang Shen - ,
Yichen Guo - ,
Yongjian Cao - ,
Kaixin Zhang - ,
Xinyan Li - ,
Rongrong Zhu - ,
Jinmeng Yi - ,
Xiaohan Yao - ,
Xiaowei Dang - ,
Rui Li - ,
Zhenzhong Zhang *- ,
Zhihai Qin *- , and
Weijing Yang *
Tumor-specific T cells play a vital role in potent antitumor immunity. However, their efficacy is severely affected by the spatiotemporal orchestration of antigen-presentation as well as the innate immune response in dendritic cells (DCs). Herein, we develop a minimalist nanovaccine that exploits a dual immunofunctional polymeric nanoplatform (DIPNP) to encapsulate ovalbumin (OVA) via electrostatic interaction when the nanocarrier serves as both STING agonist and immune adjuvant in DCs. In vitro results reveal that the nanocarrier induces STING activation via facilitating interferon regulatory factor 3 phosphorylation by block poly 18-crown-6-yl methacrylate (P18C6MA) mediated K+ perturbation cascade with endoplasmic reticulum stress, and stimulates DC maturation via the Toll-like receptor 4 activation by primary amine. In vivo studies indicate that the smart nanovaccine dramatically inhibits tumor growth with a long-term immune memory response in both the B16-OVA and EG7-OVA tumor models. After combination with programmed death ligand-1 antibody (aPD-L1), mice survival rate is notably prolonged. In addition, DIPNP forms a personalized nanovaccine after resected autologous primary tumor cell membranes decoration with a high antitumor activity in a homologous distant tumor model. The rational design provides inspiration for personalized nanovaccine construction via immunofunctional nanocarriers.
Low-Frequency Resistance Noise in Near-Magic-Angle Twisted Bilayer Graphene
Pritam Pal *- ,
Saisab Bhowmik - ,
Aparna Parappurath - ,
Saloni Kakkar - ,
Kenji Watanabe - ,
Takashi Taniguchi - , and
Arindam Ghosh *
The low-frequency resistance fluctuations, or noise, in electrical resistance not only set a performance benchmark in devices but also form a sensitive tool to probe nontrivial electronic phases and band structures in solids. Here, we report the measurement of such noise in the electrical resistance in twisted bilayer graphene (tBLG), where the layers are misoriented close to the magic angle (θ ∼ 1°). At high temperatures (T ≳ 60–70 K), the power spectral density (PSD) of the fluctuation inside the low-energy moiré bands is predominantly ∝1/f, where f is the frequency, being generally lowest close to the magic angle, and can be well-explained within the conventional McWhorter model of the ‘1/f noise’ with trap-assisted density-mobility fluctuations. At low T (≲10 K), the measured noise exhibits a strong two-level random telegraphic signal (RTS), especially close to the moiré gap, which exhibits a ∝1/f2-like PSD that can be attributed to poorly screened resonances of the Fermi energy to specific bands of defects in the encapsulating boron nitride (hBN) layers. The low-T noise within the moiré band exhibits a series of minima at the integral as well as half-integral fillings, which align with the frequently observed van Hove singularities in the density-of-states driven by strong Coulomb interaction. Apart from providing a comprehensive account of the origin and the magnitude of noise in tBLG, our experiment also reveals noise to be significantly more sensitive to the underlying interaction effects in tBLG than the conventional time-averaged transport.
Downscaling of Non-Van der Waals Semimetallic W5N6 with Resistivity Preservation
Hongze Gao - ,
Da Zhou - ,
Lu Ping - ,
Zifan Wang - ,
Nguyen Tuan Hung - ,
Jun Cao - ,
Michael Geiwitz - ,
Gabriel Natale - ,
Yuxuan Cosmi Lin - ,
Kenneth Stephen Burch - ,
Riichiro Saito - ,
Mauricio Terrones - , and
Xi Ling *
The bulk phase of transition metal nitrides (TMNs) has long been a subject of extensive investigation due to their utility as coating materials, electrocatalysts, and diffusion barriers, attributed to their high conductivity and refractory properties. Downscaling TMNs into two-dimensional (2D) forms would provide valuable members to the existing 2D materials repertoire, with potential enhancements across various applications. Moreover, calculations have anticipated the emergence of uncommon physical phenomena in TMNs at the 2D limit. In this study, we use the atomic substitution approach to synthesize 2D W5N6 with tunable thicknesses from tens of nanometers down to 2.9 nm. The obtained flakes exhibit high crystallinity and smooth surfaces. Electrical measurements on 15 samples show an average electrical conductivity of 161.1 S/cm, which persists while thickness decreases from 45.6 to 2.9 nm. The observed weak gate-tuning effect suggests the semimetallic nature of the synthesized 2D W5N6. Further investigation of the conversion mechanism elucidates the crucial role of chalcogen vacancies in the precursor for initiating the reaction and strain in propagating the conversion. Our work introduces a desired semimetallic crystal to the 2D material library with mechanistic insights for future design of the synthesis.
MXene Hollow Microsphere-Boosted Nanocomposite Electrodes for Thermocells with Enhanced Thermal Energy Harvesting Capability
Zhaopeng Liu - ,
Dianlun Wu - ,
Shouhao Wei - ,
Kangqian Xing - ,
Meilin Li - ,
Yue Jiang - ,
Rongfeng Yuan - ,
Guangming Chen - ,
Zhe Hu *- ,
Yang Huang *- , and
Zhuoxin Liu *
Thermal energy, constantly being produced in natural and industrial processes, constitutes a significant portion of energy lost through various inefficiencies. Employing the thermogalvanic effect, thermocells (TECs) can directly convert thermal energy into electricity, representing a promising energy-conversion technology for efficient, low-grade heat harvesting. However, the use of high-cost platinum electrodes in TECs has severely limited their widespread adoption, highlighting the need for more cost-effective alternatives that maintain comparable thermoelectrochemical performance. In this study, a nanocomposite electrode featuring Ti3C2Tx with hollow microsphere structures is rationally designed. This design addresses the restacking issue inherent in MXene nanosheets, increases the electrochemically active surface area, and modifies the original MXene surfaces with oxygen terminations, leading to improved redox kinetics at the electrode–electrolyte interface, particularly in n-type TECs employing Fe2+/3+ redox ions. The optimized n-type TEC achieved an output power of 84.55 μW cm–2 and a normalized power density of 0.53 mW m–2 K–2 under a ΔT of 40 K, outperforming noble platinum-based TECs by a factor of 5.5. An integrated device consisting of 32 TEC units with a p–n connection is also fabricated, which can be successfully utilized to power various small electronics. These results demonstrate the potential of MXene-based composite electrodes to revolutionize TEC technology by offering a cost-effective, high-performance alternative to traditional noble metal electrodes and contributing to efficient low-grade heat harvesting.
Framework Nucleic Acid-Based and Neutrophil-Based Nanoplatform Loading Baicalin with Targeted Drug Delivery for Anti-Inflammation Treatment
Mi Zhou - ,
Yuanlin Tang - ,
Yifei Lu - ,
Tianxu Zhang - ,
Shunhao Zhang - ,
Xiaoxiao Cai - , and
Yunfeng Lin *
Targeted drug delivery is a promising strategy for treating inflammatory diseases, with recent research focusing on the combination of neutrophils and nanomaterials. In this study, a targeted nanodrug delivery platform (Ac-PGP-tFNA, APT) was developed using tetrahedral framework nucleic acid (tFNA) along with a neutrophil hitchhiking mechanism to achieve precise delivery and anti-inflammatory effects. The tFNA structure, known for its excellent drug-loading capacity and cellular uptake efficiency, was used to carry a therapeutic agent─baicalin. The results demonstrate that the development of this drug delivery platform not only considerably enhances the bioavailability and effective concentration of the drug (baicalin) but also promotes the polarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages by modulating the interactions between the neutrophils and macrophages. This targeted therapeutic method effectively treats inflammatory conditions such as sepsis and introduces a strategy for managing inflammatory diseases characterized by neutrophil infiltration.
Asymmetric Atomic Coordination of Platinum Skin Layer on Intermetallic Platinum–Cobalt Particles
Shunsuke Kobayashi *- ,
Yuki Omori - ,
Kei Nakayama - ,
Kousuke Ooe - ,
Hsin-Hui Huang - , and
Akihide Kuwabara *
Pt-based intermetallic alloy particles with a Pt skin layer have higher catalytic activity than solid-solution alloy particles and have attracted considerable attention for practical applications in polymer electrolyte fuel cells. However, the reason for the superior performance of intermetallic alloys is not yet fully understood. Because the catalytic reaction proceeds on the topmost surface of the particle, it is necessary to clarify the relationship between the periodic structure of the intermetallic alloy and the Pt atomic coordination on the surface. This study investigated the Pt–Pt interatomic distance of a Pt skin layer formed on intermetallic Pt3Co particles at atomic resolution through precise measurements using scanning transmission electron microscopy and theoretical calculations. The Pt atomic coordination on the surface shows good agreement between experimental observations and theoretical models, although the experimental image is a projection and thus provides indirect results. The theoretical calculation model revealed that structural relaxation at the Pt and Pt3Co interfaces led to two distinct Pt bonding states at the surface, including asymmetric atomic coordination. The asymmetric coordination of the Pt site deepens the d-band center, diversifies the oxygen adsorption energies, and enhances catalytic activity. Further exploration and control of the unique surface Pt coordination environments formed on the periodic structures of intermetallic alloys should reveal promising routes for the development of catalytic particles.
Enhancing Droplet Spreading on a Hydrophobic Plant Surface by Surfactant/Cellulose Nanocrystal Complexes
Gaili Cao - ,
Weinan Zhao - ,
Lian Han - ,
Youchao Teng - ,
Shikuan Xu - ,
Han Nguyen - , and
Kam Chiu Tam *
A surfactant is an efficient and common additive used to enhance the spreading of droplets on hydrophobic surfaces. However, a high surfactant concentration is required to achieve the desired performance, resulting in environmental pollution and increased costs. Additionally, the pesticide loading capacity of surfactants at low concentrations (below their critical micelle concentrations) is a concern. Thus, in this study, we developed a strategy to enhance pesticide loading and droplet deposition by mixing small amounts of sodium dodecyl sulfate (SDS) (0.1 wt %) and cationically modified cellulose nanocrystals (PCNC). The reduced surface tension, increased viscosity and adhesion, and electrostatic and hydrogen interactions resulted in a low retraction velocity, excellent spreading, and resistance to air turbulence. The improved loading content was facilitated by the hydrophobic domains of PCNC and SDS micelles.
Molecular Determinants of Optical Modulation in ssDNA–Carbon Nanotube Biosensors
Andrew T. Krasley - ,
Sayantani Chakraborty - ,
Lela Vuković *- , and
Abraham G. Beyene *
This publication is Open Access under the license indicated. Learn More
Most traditional optical biosensors operate through molecular recognition, where ligand binding causes conformational changes that lead to optical perturbations in the emitting motif. Optical sensors developed from single-stranded DNA-functionalized single-walled carbon nanotubes (ssDNA–SWCNTs) have started to make useful contributions to biological research. However, the mechanisms underlying their function have remained poorly understood. In this study, we combine experimental and computational approaches to show that ligand binding alone is not sufficient for optical modulation in this class of synthetic biosensors. Instead, the optical response that occurs after ligand binding is highly dependent on the chemical properties of the ligands, resembling mechanisms seen in activity-based biosensors. Specifically, we show that in ssDNA–SWCNT catecholamine sensors, the optical response correlates positively with the electron density on the aryl motif, even among ligands with similar ligand binding affinities. Importantly, despite the strong correlations with electrochemical properties, we find that catechol oxidation itself is not necessary to drive the sensor optical response. We discuss how these findings could serve as a framework for tuning the performance of existing sensors and guiding the development of new biosensors of this class.
Silica-Activated Redox Signaling Confers Rice with Enhanced Drought Resilience and Grain Yield
Zhao Kang - ,
Jiankang Lu - ,
Shourong Zheng - ,
Xiaojie Hu - ,
Lianhong Wang - ,
Lijuan Jiang - ,
Yuqi Zheng - ,
Lecheng Lv - ,
Jorge L. Gardea-Torresdey - ,
Jason C. White - , and
Lijuan Zhao *
Under a changing climate, enhancing the drought resilience of crops is critical to maintaining agricultural production and reducing food insecurity. Here, we demonstrate that seed priming with amorphous silica (SiO2) nanoparticles (NPs) (20 mg/L) accelerated seed germination speed, increased seedlings vigor, and promoted seedling growth of rice under polyethylene glycol (PEG)-mimicking drought conditions. An orthogonal approach was used to uncover the mechanisms of accelerated seed germination and enhanced drought tolerance, including electron paramagnetic resonance, Fourier transform infrared spectroscopy (FTIR), metabolomics, and transcriptomics. It was revealed that the unique surface chemistry of amorphous silica, characterized by an enrichment of silanol and siloxane groups, can catalyze the production of reactive oxygen species. This, in turn, initiates redox signaling and activates downstream drought-responsive genes. In addition, silica-primed seeds exhibited a significant enrichment of 18 amino acids and 6 sugars compared to those undergoing hydropriming, suggesting the accelerated mobilization of stored energy reserves. The drought-tolerance trait was observed in vegetative tissues of 35 day-old plants, where this tolerance was associated with an accelerated catabolism of amino acids and an enhanced anabolism of antioxidants. A separated field trial showed that SiO2NPs seed priming not only increased rice grain yield by 7.77% (p = 0.051) and 6.48% (p = 0.066), respectively, under normal and drought conditions but also increased the grain amino acid content. These results demonstrate that a simple and cost-effective nanoseed-priming approach can convey life cycle-long drought tolerance while simultaneously increasing rice grain yield and nutrition quality, providing an effective and sustainable strategy to cultivate climate-resilient crops.
Concentration-Dependent Control of the Band Gap Energy of a Low-Dimensional Lepidocrocite Titanate
Adam D. Walter - ,
Gregory R. Schwenk *- ,
Yuanren Liu - ,
David Bugallo Ferron - ,
Jeffrey T. Wilk - ,
Lucas M. Ferrer - ,
Christopher Y. Li - ,
Yong-Jie Hu - , and
Michel W. Barsoum *
This publication is Open Access under the license indicated. Learn More
Recently, we reported on the simple, scalable synthesis of quantum-confined one-dimensional (1D) lepidocrocite titanate nanofilaments (1DLs). Herein, we show, using solid-state UV–vis spectroscopy, that reducing the concentration of aqueous 1DL colloidal suspensions from 40 to 0.01 g/L increases the band gap energy and light absorption onset of dried filtered films from ≈3.5 to ≈4.5 eV. This range is ascribed to quantum confinement as the system transitions from two-dimensional (2D) into 1D with dilution. It is only after the colloidal suspensions are dried and the 1DLs start to self-assemble into ribbons and sheets that the band gap values change. This self-assembly is manifested in the X-ray diffraction patterns and the emergence of a Raman band characteristic of 2D lepidocrocite titanates. In colloidal form, 1DLs exhibit a lyotropic liquid crystal phase with a critical concentration of between 10 and 1 g/L. Additionally, the Beer–Lambert law applies with a mass absorbance coefficient of 2 ± 0.4 Lg–1 cm–1. The optical absorbance edges of the colloidal suspensions are not a function of concentration. The experimental findings are theoretically supported by density functional theory calculations of the Raman vibrational modes and electronic band structures of the 1D and 2D lepidocrocite titanate atomic structures.
January 15, 2025
Anchoring of Probiotic-Membrane Vesicles in Hydrogels Facilitates Wound Vascularization
Chen Zhou - ,
Hongfu Cao - ,
Yuxiang Wang - ,
Chong Yao - ,
Yaping Zou - ,
Jingyi Liu - ,
Na Li - ,
Tun Yuan - ,
Jie Liang - ,
Qiguang Wang *- ,
Yujiang Fan *- , and
Xingdong Zhang
Inadequate vascularization significantly hampers wound recovery by limiting nutrient delivery. To address this challenge, we extracted membrane vesicles from Lactobacillus reuteri (LMVs) and identified their angiogenic potential via transcriptomic analysis. We further developed a composite hydrogel system (Gel-LMVs) by anchoring LMVs within carboxylated chitosan and cross-linking it with oxidized hyaluronic acid through a Schiff base reaction. The resulting Gel-LMVs exhibit good biocompatibility and retain the bioactivity of LMVs, which are released in a controlled manner to stimulate cell proliferation, migration, and angiogenesis in vitro by modulating gene expression in critical signaling pathways. Moreover, in an in vivo model, Gel-LMVs upregulate vascular endothelial growth factor (VEGF) and platelet endothelial cell adhesion molecule (CD31), leading to accelerated vascularization in early healing stages, while concurrently reducing inflammation and augmenting collagen deposition to enhance wound healing quality. This approach to functionalizing biomaterials with probiotic-MVs offers an advanced strategy for wound healing.
Multifunctional Nanomedicine for Targeted Atherosclerosis Therapy: Activating Plaque Clearance Cascade and Suppressing Inflammation
Cui Tang - ,
Hui Wang - ,
Lina Guo - ,
Yimin Cui - ,
Chan Zou - ,
Jianming Hu - ,
Hanyong Zhang - ,
Guoping Yang *- , and
Wenhu Zhou *
Atherosclerosis (AS) is a prevalent inflammatory vascular disease characterized by plaque formation, primarily composed of foam cells laden with lipids. Despite lipid-lowering therapies, effective plaque clearance remains challenging due to the overexpression of the CD47 molecule on apoptotic foam cells, inhibiting macrophage-mediated cellular efferocytosis and plaque resolution. Moreover, AS lesions are often associated with severe inflammation and oxidative stress, exacerbating disease progression. Herein, we introduce a multifunctional nanomedicine (CEZP) targeting AS pathogenesis via a “cell efferocytosis–lipid degradation–cholesterol efflux” paradigm, with additional anti-inflammatory properties. CEZP comprises poly(lactic-co-glycolic acid) nanoparticles encapsulated within a metal–organic framework shell coordinated with zinc ions (Zn2+) and epigallocatechin gallate (EGCG), enabling CpG encapsulation. Upon intravenous administration, CEZP accumulates at AS plaque sites, facilitating macrophage uptake and orchestrating AS treatment through synergistic mechanisms. CpG enhances cellular efferocytosis, Zn2+ promotes intracellular lipid degradation, and EGCG upregulates adenosine 5′-triphosphate-binding cassette transporters for cholesterol efflux while also exhibiting antioxidant and anti-inflammatory effects. In vivo validation confirms CEZP’s ability to stabilize plaques, reduce lipid burden, and modulate the macrophage phenotype. Moreover, CEZP is excreted from the body without safety concerns, offering a low-toxicity nonsurgical strategy for AS plaque eradication.
Long-Range Charge Transport Facilitated by Electron Delocalization in MoS2 and Carbon Nanotube Heterostructures
Daria D. Blach - ,
Dana B. Sulas-Kern - ,
Bipeng Wang - ,
Run Long - ,
Qiushi Ma - ,
Oleg V. Prezhdo - ,
Jeffrey L. Blackburn - , and
Libai Huang *
This publication is Open Access under the license indicated. Learn More
Controlling charge transport at the interfaces of nanostructures is crucial for their successful use in optoelectronic and solar energy applications. Mixed-dimensional heterostructures based on single-walled carbon nanotubes (SWCNTs) and transition metal dichalcogenides (TMDCs) have demonstrated exceptionally long-lived charge-separated states. However, the factors that control the charge transport at these interfaces remain unclear. In this study, we directly image charge transport at the interfaces of single- and multilayered MoS2 and (6,5) SWCNT heterostructures using transient absorption microscopy. We find that charge recombination becomes slower as the layer thickness of MoS2 increases. This behavior can be explained by electron delocalization in multilayers and reduced orbital overlap with the SWCNTs, as suggested by nonadiabatic (NA) molecular dynamics (MD) simulations. Dipolar repulsion of interfacial excitons results in rapid density-dependent transport within the first 100 ps. Stronger repulsion and longer-range charge transport are observed in heterostructures with thicker MoS2 layers, driven by electron delocalization and larger interfacial dipole moments. These findings are consistent with the results from NAMD simulations. Our results suggest that heterostructures with multilayer MoS2 can facilitate long-lived charge separation and transport, which is promising for applications in photovoltaics and photocatalysis.
Atomic-Level Stoichiometry Control of Ferroelectric HfxZryOz Thin Films by Understanding Molecular-Level Chemical Physical Reactions
Ngoc Le Trinh - ,
Bonwook Gu - ,
Kun Yang - ,
Chi Thang Nguyen - ,
Byungchan Lee - ,
Hyun-Mi Kim - ,
Hyeongkeun Kim - ,
Youngho Kang - ,
Min Hyuk Park *- , and
Han-Bo-Ram Lee *
HfO2-based thin films have garnered significant interest for integrating robust ferroelectricity into next-generation memory and logic chips, owing to their applicability with modern Si device technology. While numerous studies have focused on enhancing ferroelectric properties and understanding their fundamentals, the fabrication of ultrathin HfO2-based ferroelectric films has seldom been reported. This study presents the concept of atomic-level stoichiometry control of ferroelectric HfxZryOz films by examining the molecular-level interactions of precursor molecules in the atomic layer deposition (ALD) process through theoretical calculations. Atomic layer modulation (ALM) employs sequential precursor pulses, and the stoichiometries of HfxZryOz films are determined by the chemical and physical reactions predicted by theoretical simulations. The HfxZryOz ALM films demonstrate superior crystallinity and ferroelectricity compared to conventional HfxZryOz ALD films, with large polarization values reaching 2Pr = 48.8 μC/cm2 at a thickness of 4.5 nm. Because the ALM concept combines experimental and theoretical approaches, it can be applied to other applications that require multicomponent thin films with atomic-level stoichiometry control.
Exploring the Activation of Atomically Precise [Pt17(CO)12(PPh3)8]2+ Clusters: Mechanism and Energetics in Gas Phase and on an Inert Surface
Papri Chakraborty - ,
Marco Neumaier - ,
Johannes Seibel - ,
Nicola Da Roit - ,
Artur Böttcher - ,
Christian Schmitt - ,
Di Wang - ,
Christian Kübel - ,
Silke Behrens - , and
Manfred M. Kappes *
Atomically precise clusters such as [Pt17(CO)12(PPh3)8]x+ (x = 1,2) (PPh3 is triphenylphosphine) are known as precursors for making oxidation catalysts. However, the changes occurring to the cluster upon thermal activation during the formation of the active catalyst are poorly understood. We have used a combination of hybrid mass spectrometry and surface science to map the thermal decomposition of [Pt17(CO)12(PPh3)8](NO3)2. High-resolution mass and ion mobility spectrometry together with DFT-based modeling were used to probe the sequence of fragmentation reactions and fragment structures generated upon collisional excitation of [Pt17(CO)12(PPh3)8]2+. This was compared with thermal desorption spectroscopy of [Pt17(CO)12(PPh3)8](NO3)2 dropcast onto an inert graphite surface. In both cases, a characteristic sequence of CO and benzene desorption steps is observed followed at higher excitation energy by H2 loss. This behavior is indicative of Pt-catalyzed C–H activation of phenyl groups during partial stripping of the ligand shell while the Pt17P8 cluster core is retained.
Robust and Regular Micronano Binary Texture on the Complex Curved Surface for Enhanced Reendothelialization and Antithrombotic Performance
Jing Zhang - ,
Wenyuan Yu - ,
Guoqiang Li - ,
Guiling Li - ,
Baolan Chen - ,
Luwen Wang *- ,
Yang Yu *- ,
Zhiyuan Liu *- , and
Donghai Li *
Blood-contacting medical devices can easily trigger immune responses, leading to thrombosis and hyperblastosis. Constructing microtexture that provides efficient antithrombotic and rapid reendothelialization performance on complex curved surfaces remains a pressing challenge. In this work, we present a robust and regular micronano binary texture on the titanium surface, characterized by exceptional mechanical strength and precisely controlled wettability to achieve excellent hemocompatibility. Systematic in vitro and in vivo investigations confirmed that the micronano binary texture with superhydrophilic modification effectively suppressed the adhesion and activation of plasma proteins and blood cells, thereby mitigating the subsequent coagulation cascade and thrombosis. Meanwhile, the modified surface significantly upregulated the gene expression involving cell–matrix adhesion, growth factor synthesis, and calcium-mediated cytoskeleton remodeling and then accelerated the formation of a healthy and stable endothelial cell layer. This enhancement of re-endothelialization was not observed with pure titanium and superhydrophobic surfaces. Hence, superhydrophilic micronano binary texture not only significantly inhibits thrombosis but also selectively enhances the integrity and viability of the endothelial cell layer, making it a promising strategy for improving the long-term anticoagulation performance of vascular implants.
Advances, Challenges, and Opportunities in Plasmonic Nanogap-Enhanced Raman Scattering with Nanoparticles
Gyeong-Hwan Kim - ,
Jiwoong Son - , and
Jwa-Min Nam *
Surface-enhanced Raman scattering has been widely used for molecular/material characterization and chemical and biological sensing and imaging applications. In particular, plasmonic nanogap-enhanced Raman scattering (NERS) is based on the highly localized electric field formed within the nanogap between closely spaced metallic surfaces to more strongly amplify Raman signals than the cases with molecules on metal surfaces. Nanoparticle-based NERS offers extraordinarily strong Raman signals and a plethora of opportunities in sensing, imaging and many different types of biomedical applications. Despite its potential, several challenges still remain for NERS to be widely useful in real-world applications. This Perspective introduces various plasmonic nanogap configurations with nanoparticles, discusses key advances and critical challenges while addressing possible misunderstandings in this field, and provides future directions for NERS to generate stronger, more uniform, and stable signals over a large number of structures for practical applications.
Induction of Antigen-Specific Tolerance in a Multiple Sclerosis Model without Broad Immunosuppression
Rebeca T. Stiepel - ,
Sean R. Simpson - ,
Nicole Rose Lukesh - ,
Denzel D. Middleton - ,
Dylan A. Hendy - ,
Luis Ontiveros-Padilla - ,
Stephen A. Ehrenzeller - ,
Md Jahirul Islam - ,
Erik S. Pena - ,
Michael A. Carlock - ,
Ted M. Ross - ,
Eric M. Bachelder - , and
Kristy M. Ainslie *
Multiple sclerosis (MS) is a severe autoimmune disorder that wreaks havoc on the central nervous system, leading to a spectrum of motor and cognitive impairments. There is no cure, and current treatment strategies rely on broad immunosuppression, leaving patients vulnerable to infections. To address this problem, our approach aims to induce antigen-specific tolerance, a much-needed shift in MS therapy. We have engineered a tolerogenic therapy consisting of spray-dried particles made of a degradable biopolymer, acetalated dextran, and loaded with an antigenic peptide and tolerizing drug, rapamycin (Rapa). After initial characterization and optimization, particles were tested in a myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis model of MS. Representing the earliest possible time of diagnosis, mice were treated at symptom onset in an early therapeutic model, where particles containing MOG and particles containing Rapa+MOG evoked significant reductions in clinical score. Particles were then applied to a highly clinically relevant late therapeutic model during peak disease, where MOG particles and Rapa+MOG particles each elicited a dramatic therapeutic effect, reversing hind limb paralysis and restoring fully functional limbs. To confirm the antigen specificity of our therapy, we immunized mice against the influenza antigen hemagglutinin (HA) and treated them with MOG particles or Rapa+MOG particles. The particles did not suppress antibody responses against HA. Our findings underscore the potential of this particle-based therapy to reverse autoimmunity in disease-relevant models without compromising immune competence, setting it apart from existing treatments.
Moisture-Electric Generators Working in Subzero Environments Based on Laser-Engraved Hygroscopic Hydrogel Arrays
Fei Yu - ,
Liying Wang - ,
Xijia Yang - ,
Yue Yang - ,
Xuesong Li *- ,
Yang Gao - ,
Yi Jiang - ,
Ke Jiang - ,
Wei Lü *- ,
Xiaojuan Sun *- , and
Dabing Li
Moisture-electric generators (MEGs) generate power by adsorbing water from the air. However, their performance at low temperatures is hindered due to icing. In the present work, MEG arrays are developed by laser engraving techniques and a modulated low-temperature hydrogel as the absorbent material. LTH effectively captures moisture and maintains ion dissociation and migration even at subzero temperatures. Based on the double electric layer pseudocapacitance model, the oscillating circuit theory is introduced to explain the effects of moisture absorption, evaporation, and ion migration on the output current of the MEG, and the circuit calculations are matched with the experimental results. Molecular dynamics simulations indicate that LTH’s low-temperature stability results from preferential hydrogen bonding between glycerol molecules and H2O, which disrupts H2O–H2O hydrogen bonds and slows water crystallization. A single MEG unit (0.25 cm2) can produce up to ∼0.8 V and ∼21.2 μW/cm2 at room temperature, and at −35 °C with 16% RH, it generates ∼0.58 V and ∼14.35 μA. MEG realizes the following applications: MEG successfully drives electronic devices in snow; arrays of 16 MEGs can power portable electronics, and 384 MEGs can achieve up to 210 V; MEG absorbs moisture in water and drives LEDs by blowing up; MEG has a flexible wearable nature; MEG is used for respiratory monitoring and photoelectric sensors.
Parameter Pool-Assisted Centrifugation Sorter for Multiscale Higher-Order DNA Nanomaterials
Lilin Ouyang - ,
Junke Wang - ,
Bing Liu - ,
Mo Xie - ,
Lianhui Wang - ,
Chunhai Fan - , and
Jie Chao *
Higher-order DNA nanomaterials have emerged as programmable tools for probing biological processes, constructing metamaterials, and manipulating mechanically active nanodevices with the multifunctionality and high-performance attributes. However, their utility is limited by intricate mixtures formed during hierarchical multistage assembly, as standard techniques like gel electrophoresis lack the resolution and applicability needed for precise characterization and enrichment. Thus, it is urgent to develop a sorter that provides high separation resolution, broad scope, and bioactive functionality. Here, we present a versatile and scalable sorting pipeline based on a centrifugation parameter pool capable of distinguishing DNA nanomaterials across multiple scales. By tuning parameters, we achieved high-throughput classification of nanostructures, spanning from DNA tile-based constructs to DNA origami-based assemblies (∼50 MDa, 75,000 bp), surpassing conventional methods. Furthermore, we optimized the separation resolution to less than 78 kDa (∼120 bp) at a large scale by sorting DNA tetrahedron structures using this systematic parameter pool-assisted centrifugation strategy. This sorter maintains the integrity and functionality of bioactive materials, facilitating a seamless transition from assembly to application, allowing for integration with proteins and other components to achieve the fabrication of complex functional materials and programmable molecular machines across interdisciplinary fields within the nanotechnology community.
Solid-State Nanopore Real-Time Assay for Monitoring Cas9 Endonuclease Reactivity
Chalmers C. C. Chau *- ,
Nicole E. Weckman - ,
Emma E. Thomson - , and
Paolo Actis
This publication is Open Access under the license indicated. Learn More
The field of nanopore sensing is now moving beyond nucleic acid sequencing. An exciting avenue is the use of nanopore platforms for the monitoring of biochemical reactions. Biological nanopores have been used for this application, but solid-state nanopore approaches have lagged. This is due to the necessity of using higher salt conditions (e.g., 4 M LiCl) to improve the signal-to-noise ratio which completely abolish the activities of many biochemical reactions. We pioneered a polymer electrolyte solid-state nanopore approach that maintains a high signal-to-noise ratio even at a physiologically relevant salt concentration. Here, we report the monitoring of the restriction enzyme SwaI and CRISPR-Cas9 endonuclease activities under physiological salt conditions and in real time. We investigated the dsDNA cleavage activity of these enzymes in a range of digestion buffers and elucidated the off-target activity of CRISPR-Cas9 ribonucleoprotein endonuclease in the presence of single base pair mismatches. This approach enables the application of solid-state nanopores for the dynamic monitoring of biochemical reactions under physiological salt conditions.
Enormous Out-of-Plane Charge Rectification and Conductance through Two-Dimensional Monolayers
Anthony Cabanillas - ,
Simran Shahi - ,
Maomao Liu - ,
Hemendra Nath Jaiswal - ,
Sichen Wei - ,
Yu Fu - ,
Anindita Chakravarty - ,
Asma Ahmed - ,
Xiaochi Liu - ,
Jian Sun - ,
Cheng Yang - ,
Won Jong Yoo - ,
Theresia Knobloch - ,
Vasili Perebeinos - ,
Antonio Di Bartolomeo - ,
Tibor Grasser *- ,
Fei Yao *- , and
Huamin Li *
Heterogeneous integration of emerging two-dimensional (2D) materials with mature three-dimensional (3D) silicon-based semiconductor technology presents a promising approach for the future development of energy-efficient, function-rich nanoelectronic devices. In this study, we designed a mixed-dimensional junction structure in which a 2D monolayer (e.g., graphene, MoS2, and h-BN) is sandwiched between a metal (e.g., Ti, Au, and Pd) and a 3D semiconductor (e.g., p-Si) to investigate charge transport properties exclusively in an out-of-plane (OoP) direction. The role of 2D monolayers as either an OoP metal-to-semiconductor charge injection barrier or an OoP semiconductor-to-metal charge collection barrier was comparatively evaluated. Compared to monolayer graphene, monolayer MoS2 and h-BN effectively modulate OoP metal-to-semiconductor charge injection through a barrier tunneling effect. Their effective OoP resistance and resistivity were extracted using a resistors-in-series model. Intriguingly, when functioning as a semiconductor-to-metal charge collection barrier, all 2D monolayers become electronically “transparent” (close to zero resistance) when a high OoP voltage (greater than the built-in voltage) is applied. As a mixed-dimensional integrated diode, the Ti/MoS2/p-Si and Au/MoS2/p-Si configurations exhibit both high OoP rectification ratios (5.4 × 104) and conductance (1.3 × 105 S/m2). Our work demonstrates the tunable OoP charge transport characteristics at a 2D/3D interface, suggesting the opportunity for 2D/3D heterogeneous integration, even with sub-1 nm thick 2D monolayers, to enhance modern Si-based electronic devices.
The Road to Commercializing Optical Metasurfaces: Current Challenges and Future Directions
Younghwan Yang - ,
Eunji Lee - ,
Yujin Park - ,
Junhwa Seong - ,
Hongyoon Kim - ,
Hyunjung Kang - ,
Dohyun Kang - ,
Doohyuk Han - , and
Junsuk Rho *
Optical metasurfaces, components composed of artificial nanostructures, are recognized for pushing boundaries of wavefront manipulation while maintaining a lightweight, compact design that surpasses conventional optics. Such advantages align with the current trends in optical systems, which demand compact communication devices and immersive holographic projectors, driving significant investment from the industry. Although interest in commercialization of optical metasurfaces has steadily grown since the initial breakthrough with diffraction-limited focusing, their practical applications have remained limited by challenges such as, massive-production yield, absence of standardized evaluation methods, and constrained design methodology. Here, this Perspective addresses the challenges in commercialization of optical metasurfaces, particularly focused on mass production, fabrication tolerance, performance evaluation, and integration into commercial systems. Additionally, we select the fields where metasurfaces may soon play significant roles and provide a perspective on their potentials. By addressing the challenges and exploring the solutions, this Perspective aims to foster discussions that will accelerate the utilization of optical metasurfaces and further build near-future metaphotonics platforms.
Revealing the Limitations of the Thermocapacitive Cycle
Yining Lao - ,
Pei Tang - ,
Jinquan Zeng - ,
Shan Xu - ,
Jian Zhu - ,
Qingyun Dou - ,
Xiaohua Xiao - , and
Xingbin Yan *
While thermoelectric conversion by a thermocapacitive cycle has been considered a promising green technology for low-grade heat recovery, our study finds that its practical feasibility is overestimated. During thermal charging, the coexistence and dynamic competition between thermal-induced voltage rise and self-discharge lead to the limitations of the thermocapacitive cycle. Therefore, the operational conditions in the charge-heat-discharge steps seriously restrict the thermal charging performance. The calculation of energy efficiency further confirms the economic infeasibility of the thermocapacitive cycle. This study provides insights into comprehending the principle and process of thermoelectric conversion by thermocapacitive cycle and will guide the rational development of capacitive heat-to-current converters.
A Thermally Robust Biopolymeric Separator Conveys K+ Transport and Interfacial Chemistry for Longevous Potassium Metal Batteries
Yuyuan Wang - ,
Liang Xu - ,
Xiaopeng Chen - ,
Ziang Chen - ,
Xinhua Li - ,
Wenyi Guo - ,
Tao Cheng *- ,
Yuyang Yi *- , and
Jingyu Sun *
Potassium metal batteries (KMBs) hold promise for stationary energy storage with certain cost and resource merits. Nevertheless, their practicability is greatly handicapped by dendrite-related anodes, and the target design of specialized separators to boost anode safety is in its nascent stage. Here, we develop a thermally robust biopolymeric separator customized via a solvent-exchange and amino-siloxane decoration strategy to render durable and safe KMBs. Through experimental investigation and theoretical computation, we reveal that the optimized porosity and surface functionalization could manage ion transport and interfacial chemistry, thereby enabling efficient K+ diffusion and a favorable solid electrolyte interphase to achieve prolonged cycling stability (over 3000 h). The thus-assembled full cell retains 80% of its initial capacity after 400 cycles at 0.5 A g–1. The heat-proof property of the designed separator is further demonstrated. Our biopolymeric separator, affording multifunctional features, provides an appealing solution to circumvent instability and safety issues associated with potassium metal batteries.
Deciphering the Sulfur-Involved Bonding Interactions in Sulfurized Polyacrylonitrile: The Formation Thermodynamics and the Roles in Electrochemical Characteristics
Jingyi Xie - ,
Junxiong Chen - ,
Lingling Guo - ,
Yande Li - ,
Yibo Wang - ,
Shun Zheng - ,
Nian Zhang - ,
Jianwei Meng - ,
Kaiyu Zhang - ,
Qinghao Li *- ,
Tsu-Chien Weng *- ,
Pengfei Yu *- , and
Xiaosong Liu *
Sulfurized polyacrylonitrile (SPAN) exhibits a very high cycle stability by overcoming the shuttle effect of conventional Li–S batteries. However, there are still controversies in SPAN about the bonding types of sulfur with the matrix, their critical synthesis temperature regions, and their roles in the electrochemical lithium storage reaction, seriously hindering the economical synthesis of SPAN, the optimization of performances, and the exploration of other SPAN-like alternatives. The key to solving the above problems lies in accurate measurements of the thermodynamic evolution of bonding interactions in the synthesis process as well as in the electrochemical process. In this study, soft and tender X-ray absorption spectroscopy (XAS) is utilized to achieve a fine resolution of specific bonding interactions through the selective excitation of C, N, and S. Sulfur-involved bonding interactions have been elucidated, including the bonding type, critical temperature region, linking site, and their interplays. Furthermore, their contributions to lithium storage and their regulations on electrochemical performances are discussed. This study demonstrates the resolving capability of XAS for organic electrode materials and provides insights for further analyzing the cyclability of SPAN and rationally designing alternatives from the perspective of bonding interactions.
Capillary-Assisted Confinement Assembly for Advanced Sensor Fabrication: From Superwetting Interfaces to Capillary Bridge Patterning
Zhihao Zhao - ,
Weijie Wang - ,
Gongmo Xiang - ,
Lei Jiang - , and
Xiangyu Jiang *
Precise patterning of sensing materials, particularly the long-range-ordered assembly of micro/nanostructures, is pivotal for improving sensor performance, facilitating miniaturization, and enabling seamless integration. This paper examines the importance of interfacial confined assembly in sensor patterning, including gas–liquid and liquid–liquid confined assembly, wettability-assisted or microstructure-assisted solid–liquid interfacial confined assembly, and tip-induced confined assembly. The application of capillary bridge confined assembly technology in chemical sensors, flexible electronics, and optoelectronics is highlighted. The advantages of capillary bridge confined assembly technology include the ability to achieve high-resolution patterning, scalability, and material arrangement in long-range order. It is, therefore, an ideal processing platform for next-generation sensors. Finally, the broad prospects of this technology in the miniaturization and integration of high-performance multifunctional sensors are discussed.
January 14, 2025
Liquid Active Surface Growth: Explaining the Symmetry Breaking in Liquid Nanoparticles
Huai Lin - ,
Huiying Guo - ,
Xuejun Cheng - ,
An Su - ,
Liping Huang - ,
Qingwu Yao - ,
Xiaohuo Shi - ,
Ruoxu Wang *- , and
Hongyu Chen *
In our previous studies of metal nanoparticle growth, we have come to realize that the dynamic interplay between ligand passivation and metal deposition, as opposed to static facet control, is responsible for focused growth at a few active sites. In this work, we show that the same underlying principle could be applied to a very different system and explain the abnormal growth modes of liquid nanoparticles. In such a liquid active surface growth (LASG), the interplay between droplet expansion and simultaneous silica shell encapsulation gives rise to an active site of growth, which eventually becomes the long necks of nanobottles. For this synthetic control, the imbalance of the said interplay is the critical factor, as demonstrated by carefully designed control experiments. Thus, LASG provides a coherent mechanism that encompasses a wide range of liquid-derived nanostructures, including hollow nanospheres, asymmetric teardrops, and hollow nanobottles with an opening. By adapting nanosynthesis techniques from the solid to liquid realm, we believe that LASG would provide deeper insights and more sophisticated synthetic controls.
Shape Anisotropy-Dependent Leaking in Magnetic Neurons for Bio-Mimetic Neuromorphic Computing
Thomas Leonard - ,
Nicholas Zogbi - ,
Samuel Liu - ,
William S. Rogers - ,
Christopher H. Bennett - , and
Jean Anne C. Incorvia *
Spiking neural networks seek to emulate biological computation through interconnected artificial neuron and synapse devices. Spintronic neurons can leverage magnetization physics to mimic biological neuron functions, such as integration tied to magnetic domain wall (DW) propagation in a patterned nanotrack and firing tied to the resistance change of a magnetic tunnel junction (MTJ), captured in the domain wall-magnetic tunnel junction (DW-MTJ) device. Leaking, relaxation of a neuron when it is not under stimulation, is also predicted to be implemented based on DW drift as a DW relaxes to a low energy position, but it has not been well explored or demonstrated in device prototypes. Here, we study DW-MTJ artificial neurons capable of leaky integrate-and-fire (LIF) behavior and demonstrate geometry-dependent leaking dynamics that results in repeatable, tunable LIF operation. Studying the behavior of five different device designs, we show tuning the geometry, stimulating fields and currents, and location of electrical contacts results in a wide range of neuron behavior. Additionally, implementation of an asymmetric notch allows for nonlinear pinning which increased expressivity without sacrificing leaking. The measured behavior is implemented in a simulated spiking neural network that outperforms a 1D model of continuous DW motion and approaches the performance of an ideal LIF activation function. The results show that the analog LIF capability of DW-MTJ neurons combines many desirable neuron functions into a single device, which can result in varied forms of multifunctional neuromorphic computing.
Oxygen-Passivated Sulfur Vacancies in Monolayer MoS2 for Enhanced Piezoelectricity
Ajay Kumar Verma - ,
Md. Ataur Rahman - ,
Pargam Vashishtha - ,
Xiangyang Guo - ,
Manoj Sehrawat - ,
Rahul Mitra - ,
Sindhu P. Giridhar - ,
Moaz Waqar - ,
Ankit Bhoriya - ,
Billy J. Murdoch - ,
Chenglong Xu - ,
Ali Zavabeti - ,
Wei Qian Song - ,
Yongxiang Li - ,
Sanjay R. Dhakate - ,
Bhasker Gahtori - ,
Taimur Ahmed - ,
Irfan H. Abidi *- , and
Sumeet Walia *
Modern-day applications demand onboard electricity generation that can be achieved using piezoelectric phenomena. Reducing the dimensionality of materials is a pathway to enhancing the piezoelectric properties. Transition-metal dichalcogenides have been shown to exhibit high piezoelectricity. Monolayer MoS2 possesses strong piezoelectricity that is otherwise negligible in its bulk form. The presence of sulfur vacancy defects in two-dimensional MoS2 can starkly reduce piezoelectric output due to enhanced charge screening. Oxygen passivation offers thermodynamically favorable and superior vacancy passivation. Here, we demonstrate an in situ oxygen passivation of sulfur vacancies achieved by performing chemical vapor deposition in atmospheric pressure conditions, resulting in a dramatically enhanced piezoelectric output. We achieved an out-of-plane effective piezoelectric coefficient d33eff 0.54 pm/V for the MoS2 monolayer with sulfur vacancies (SV-MoS2) and 0.94 pm/V where sulfur vacancies are passivated by oxygen (OP-MoS2). The piezoelectric device (PED) based on OP-MoS2 exhibits 26% higher output voltage than SV-MoS2 with the maximum peak-to-peak value of 0.95 V. Additionally, we show that the OP-MoS2-based PED can charge a 330 nF capacitor 30% faster than the SV-MoS2 PED for up to 50 mV in 0.5 s by repetitive finger tapping. The evolution of piezoelectricity in MoS2 with sulfur vacancy defect manipulation promises an avenue for scalable defect engineering for next-generation applications in miniaturized self-powered electronics and sensors across computing, healthcare, and size-, weight-, and power-constrained environments.
Symmetric Diblock Copolymers Form Versatile and Switchable Ultrasmall Nanoparticles
Artem Petrov *- ,
Guillermo A. Hernández-Mendoza - , and
Alfredo Alexander-Katz *
Block copolymers (BCPs) can form nanoparticles having different morphologies that can be used as photonic nanocrystals and are a platform for drug delivery, sensors, and catalysis. In particular, BCP nanoparticles having disk-like shape have been recently discovered. Such nanodisks can be used as the next-generation antitumor drug delivery carriers; however, the applicability of the existing nanodisks is limited due to their poor or unknown ability to respond to external stimuli. In this work, we showed that the simplest symmetric diblock copolymers in equilibrium can form nanodisks that can be reversibly switched into a multitude of various nanoparticles potentially applicable in nanophotonics, biomedicine, and hierarchical self-assembly. These structures include patchy and onion-like nanoparticles, striped ellipsoids, mixed morphology nanocolloids, and spherical micelles. The transitions between nanodisks and the aforementioned nanoparticles are sharp, direct, and can be achieved by tuning the block–block and polymer–solvent incompatibility. We demonstrated that this versatility of nanoparticle morphologies can be achieved upon reducing the nanoparticle size to approximately two lamellar periods of the BCP. Upon aggregation of such small nanocolloids, a larger assembly can be formed. In turn, these bigger particles could form many other structures including a chain-like supramolecular aggregate of nanodisks and a multilayered disk-like nanoparticle. We obtained our results by performing self-consistent field theory calculations according to an algorithm designed to produce equilibrium nanoparticle morphology. This work demonstrates that nanodisks prepared from the simplest type of BCPs are extremely tunable; therefore, symmetric diblock copolymers can become a platform for producing the next-generation stimuli-responsive nanoparticles.
Direct Electrical Access to the Spin Manifolds of Individual Lanthanide Atoms
Gregory Czap - ,
Kyungju Noh - ,
Jairo Velasco Jr.- ,
Roger M. Macfarlane - ,
Harald Brune *- , and
Christopher P. Lutz *
This publication is Open Access under the license indicated. Learn More
Lanthanide atoms show long magnetic lifetimes because of their strongly localized 4f electrons, but electrical control of their spins has been difficult because of their closed valence shell configurations. We achieved electron spin resonance of individual lanthanide atoms using a scanning tunneling microscope to probe the atoms bound to a protective insulating film. The atoms on this surface formed a singly charged cation state having an unpaired 6s electron, enabling tunnel current to access their 4f electrons. Europium spectra display a rich array of transitions among the 54 combined electron and nuclear spin states. In contrast, samarium’s ground state is a Kramers doublet with a very large g-factor of 5. These results demonstrate that all-electronic sensing and control of individual lanthanide spins is possible for quantum devices and spin-based electronics by using their rarely observed monovalent cation state.
Olfactory-Inspired Separation-Sensing Nanochannel-Based Electronics for Wireless Sweat Monitoring
Yuge Wu - ,
Qi Wang - ,
Xin Li - ,
Ke Li - ,
Dehua Huang - ,
Kehan Zou - ,
Zhehua Zhang - ,
Yongchao Qian - ,
Congcong Zhu *- ,
Xiang-Yu Kong - , and
Liping Wen *
Human sweat has the potential to be sufficiently utilized for noninvasive monitoring. Given the complexity of sweat secretion, the sensitivity and selectivity of sweat monitoring should be further improved. Here, we developed an olfactory-inspired separation-sensing nanochannel-based electronic for sensitive and selective sweat monitoring, which was simultaneously endowed with interferent separation and target detection performances. The special separation-sensing strategy imparts functional composite membranes with a high sensitivity of 113 mV dec–1 for potassium detection. The excellent mechanical properties and conformability of the Kevlar aramid nanofiber layer bring well-wearing performances to realize continuous wireless sweat monitoring. The recognition between functional molecules and target ions is proved at the molecular level in detail in the article. The replacement of functional molecules proves the universality of the strategy for performance enhancement in intricate biofluid analysis systems.
Creation of Piezoelectricity in Quadruple Perovskite Oxides by Harnessing Cation Defects and Their Application in Piezo-Photocatalysis
Kai Wang - ,
Xiangyu Guo *- ,
Chen Han - ,
Lihong Liu *- ,
Zhiliang Wang - ,
Lars Thomsen - ,
Peng Chen - ,
Zongping Shao - ,
Xudong Wang *- ,
Fang Xie - ,
Gang Liu - ,
Lianzhou Wang *- , and
Shaomin Liu *
Quadruple perovskite oxides have received extensive attention in electronics and catalysis, owing to their cation-ordering structure and intriguing physical properties. However, their repertoires still remain limited. In particular, piezoelectricity from quadruple perovskites has been rarely reported due to the frustrated symmetry-breaking transition in A-site-ordered perovskite structures, disabling their piezoelectric applications. Herein, we report a feasible strategy to achieve piezoelectricity in CaCu3Ti4O12 (CCTO) quadruple perovskite via cation defect engineering, specifically through a thermal-driven selective cation exsolution strategy to introduce Cu vacancies. The introduction of Cu point defects in CCTO locally destabilizes the constrained tilted TiO6 octahedra framework, relaxing the octahedral tilting and inducing structural heterogeneity which, in turn, disrupts the high symmetry of the pristine cubic phase. As a result, the defective CCTO with localized asymmetry exhibits intense polarization and a robust piezoelectricity of 7 pC N–1. The created piezoelectricity is further validated by its application as a piezo-photocatalyst, enabling efficient charge separation and transfer with a 2.5-times increment in the lifetime of photoexcitations. This enhancement leads to a 3.86- and 31-fold increase in the production of hydrogen peroxide and reactive oxygen species compared with individual piezocatalysis and photocatalysis, respectively. This study establishes a pathway to engineer piezoelectricity in quadruple perovskites, potentially unlocking a wide range of applications in modern microelectronics beyond the demonstrated piezo-photocatalysis.
Revealing Multistep Phase Separation in Metal Alloy Nanoparticles with In Situ Transmission Electron Microscopy
Yingying Jiang - ,
Zicong Marvin Wong - ,
Hongwei Yan - ,
Teck Leong Tan - , and
Utkur Mirsaidov *
Phase separation plays a crucial role in many natural and industrial processes, such as the formation of clouds and minerals and the distillation of crude oil. In metals and alloys, phase separation is an important approach often utilized to improve their mechanical strength for use in construction, automobile, and aerospace manufacturing. Despite its importance in many processes, the atomic details of phase separation are largely unknown. In particular, it is unclear how a different crystal phase emerges from the parent alloy. Here, using real-time in situ transmission electron microscopy, we describe the stages of the phase separation in face-centered cubic (fcc) AuRu alloy nanoparticles, resulting in a Ru phase with a hexagonal close-packed (hcp) crystal structure. Our observation reveals that the hcp Ru phase forms in two steps: the spinodal decomposition of the alloy produces metastable fcc Ru clusters, and as they grow larger, these clusters transform into hcp Ru domains. Our calculations indicate that the primary reason for the fcc-to-hcp transformation is the size-dependent competition between the interfacial and bulk energies of Ru domains. These insights into elusive, transient steps in the phase separation of alloys can aid in engineering nanomaterials with unconventional phases.
Inhalable Metal–Organic Frameworks: A Promising Delivery Platform for Pulmonary Diseases Treatment
Qifan Yu - ,
Qiang Zhang - ,
Zhiqiang Wu - , and
Yang Yang *
Inhalation delivery, offering a direct pathway for administering drugs to the lungs in the form of dry powders or aerosols, stands out as an optimal approach for the localized treatment of pulmonary diseases. However, the intricate anatomical architecture of the lung often poses challenges in maintaining effective drug concentrations within the lungs over extended periods. This highlights the pressing need to develop rational inhalable drug delivery systems that can improve treatment outcomes for respiratory diseases. Metal–organic frameworks (MOFs) assembled from inorganic metal ions and organic ligands, characterized by customizable porous architecture and chemical composition, modifiable porosity, vast surface area, straightforward surface modification, and adjustable biocompatibility, have garnered extensive attention in the biomedical sphere. The introduction of MOFs into inhalation therapy represents a promising avenue to navigate past the hurdles associated with traditional inhalation methods. Therefore, this review summarizes the characteristics of inhalation delivery together with the latest advances, challenges, and opportunities in utilizing inhalable MOFs for treating lung diseases and discusses prospects in this field alongside the potential pathways for translating this strategy into clinic.
Heteroconfinement in Single CdTe Nanoplatelets
Tasnim Ahmed - ,
Xuanheng Tan - ,
Barry Y. Li - ,
Elijah Cook - ,
Jillian Williams - ,
Sophia M. Tiano - ,
Belle Coffey - ,
Stephanie M. Tenney - ,
Dugan Hayes - , and
Justin R. Caram *
Dimension-engineered synthesis of atomically thin II–VI nanoplatelets (NPLs) remains an open challenge. While CdSe NPLs have been made with confinement ranging from 2 to 11 monolayers (ML), CdTe NPLs have been significantly more challenging to synthesize and separate. Here we provide detailed mechanistic insight into the layer-by-layer growth kinetics of the CdTe NPLs. Combining ensemble and single-particle spectroscopic and microscopic tools, our work suggests that beyond 2 ML CdTe NPLs, higher ML structures initially appear as heteroconfined materials with colocalized multilayer structures. In particular, we observe strongly colocalized 3 and 4 ML emissions, accompanied by a broad trap emission. Accompanying transient absorption, single-particle optical, and atomic force microscopy analyses suggest islands of different MLs on the same NPL. To explain the nonstandard nucleation and growth of these heteroconfined structures, we simulated the growth conditions of NPLs and quantified how the monomer binding energy modifies the kinetics and permits single NPLs with multi-ML structures. Our findings suggest that the lower bond energy associated with CdTe relative to CdSe limits higher ML syntheses and explains the observed differences between CdTe and CdSe growth.
January 13, 2025
Tumor Vaccine Exploiting Membranes with Influenza Virus-Induced Immunogenic Cell Death to Decorate Polylactic Coglycolic Acid Nanoparticles
Ying Yang - ,
Yongmao Hu - ,
Ying Yang - ,
Qingwen Liu - ,
Peng Zheng - ,
Zhongqian Yang - ,
Biao Duan - ,
Jinrong He - ,
Weiran Li - ,
Duo Li - ,
Xiao Zheng - ,
Mengzhen Wang - ,
Yuting Fu - ,
Qiong Long *- , and
Yanbing Ma *
Immunogenic cell death (ICD) of tumor cells, which is characterized by releasing immunostimulatory “find me” and “eat me” signals, expressing proinflammatory cytokines and providing personalized and broad-spectrum tumor antigens draws increasing attention in developing a tumor vaccine. In this study, we aimed to investigate whether the influenza virus (IAV) is efficient enough to induce ICD in tumor cells and an extra modification of IAV components such as hemeagglutinin (HA) will be helpful for the ICD-induced cells to elicit robust antitumor effects; in addition, to evaluate whether the membrane-engineering polylactic coglycolic acid nanoparticles (PLGA NPs) simulating ICD immune stimulation mechanisms hold the potential to be a promising vaccine candidate, a mouse melanoma cell line (B16–F10 cell) was infected with IAV rescued by the reverse genetic system, and the prepared cells and membrane-modified PLGA NPs were used separately to immunize the melanoma-bearing mice. IAV-infected tumor cells exhibit dying status, releasing high mobility group box-1 (HMGB1) and adenosine triphosphate (ATP), and exposing calreticulin (CRT), IAV hemeagglutinin (HA), and tumor antigens like tyrosinase-related protein 2 (TRP2). IAV-induced ICD cells enhance biomass-derived carbon (BMDCs) migration, antigen uptake, cross-presentation, and maturation in vitro. Furthermore, immunization with IAV-induced ICD cells effectively suppressed tumor growth in melanoma-bearing mice. The isolated cell membrane inherited the immunological characteristics from the ICD cells and elicited robust antitumor immune responses through decorating PLGA NPs loading with a tumor-specific helper T-cell peptide and supplemented with ATP in a hydrogel system. This study indicated a promising strategy for developing cell-based and personalized tumor vaccines through fully taking advantage of the immune stimulation mechanisms of ICD occurrence in tumor cells, IAV modification, and nanoscale delivery.
Transforming Detrimental Crystalline Zinc Hydroxide Sulfate to Homogeneous Fluorinated Amorphous Solid–Electrolyte Interphase on Zinc Anode
Siyu Tian - ,
Taesoon Hwang - ,
Zhuoxun Zhang - ,
Shiwen Wu - ,
Amirarsalan Mashhadian - ,
Renzheng Zhang - ,
Tye Milazzo - ,
Tengfei Luo - ,
Ruda Jian - ,
Tianyi Li - ,
Kyeongjae Cho *- , and
Guoping Xiong *
The formation of non-ion conducting byproducts on zinc anode is notoriously detrimental to aqueous zinc-ion batteries (AZIBs). Herein, we successfully transform a representative detrimental byproduct, crystalline zinc hydroxide sulfate (ZHS) to fast-ion conducting solid-electrolyte interphase (SEI) via amorphization and fluorination induced by suspending CaF2 nanoparticles in dilute sulfate electrolytes. Distinct from widely reported nonhomogeneous organic–inorganic hybrid SEIs that exhibit structural and chemical instability, the designed single-phase SEI is homogeneous, mechanically robust, and chemically stable. These characteristics of the SEI facilitate the prevention of zinc dendrite growth and reduction of capacity loss during long-term cycling. Importantly, AZIB full cells based on this SEI-forming electrolyte exhibit exceptional stability over 20,000 cycles at 3 A/g with a charging voltage of 2.2 V without short circuits and electrolyte dry-out. This work suggests avenues for designing SEIs on a metal anode and provides insights into associated SEI chemistry.
Perovskite Nanocrystal Self-Assemblies in 3D Hollow Templates
Etsuki Kobiyama - ,
Darius Urbonas - ,
Benjamin Aymoz - ,
Maryna I. Bodnarchuk *- ,
Gabriele Rainò - ,
Antonis Olziersky - ,
Daniele Caimi - ,
Marilyne Sousa - ,
Rainer F. Mahrt - ,
Maksym V. Kovalenko *- , and
Thilo Stöferle *
This publication is Open Access under the license indicated. Learn More
Highly ordered nanocrystal (NC) assemblies, namely, superlattices (SLs), have been investigated as materials for optical and optoelectronic devices due to their unique properties based on interactions among neighboring NCs. In particular, lead halide perovskite NC SLs have attracted significant attention owing to their extraordinary optical characteristics of individual NCs and collective emission processes like superfluorescence (SF). So far, the primary method for preparing perovskite NC SLs has been the drying-mediated self-assembly method, in which the colloidal NCs spontaneously assemble into SLs during solvent evaporation. However, this method lacks controllability because NCs form random-sized SLs at random positions on the substrate, rendering NC assemblies in conjunction with device structures, such as photonic waveguides or microcavities, challenging. Here, we demonstrate template-assisted self-assembly to deterministically place perovskite NC SLs and control their geometrical properties. A solution of CsPbBr3 NCs is drop-casted on a substrate with lithographically defined hollow structures. After solvent evaporation and removal of excess NCs from the substrate surface, NCs remain only in the templates, thereby defining the position and size of these NC assemblies. We performed photoluminescence (PL) measurements on these NC assemblies and observed signatures of SF, similar to those in spontaneously assembled SLs. Our findings are crucial for optical devices that harness embedded perovskite NC assemblies and enable fundamental studies on how these collective effects can be tailored through the SL geometry.
Combating Antibiotic-Resistant Bacterial Infection Using Coassembled Dimeric Antimicrobial Peptide-Based Nanofibers
Guoyu Li - ,
Haoran Deng - ,
Wanying Xu - ,
Wenwen Chen - ,
Zhenheng Lai - ,
Yongjie Zhu - ,
Licong Zhang - ,
Changxuan Shao *- , and
Anshan Shan *
The emergence of multidrug-resistant (MDR) pathogens, coupled with the limited effectiveness of existing antibiotics in eradicating biofilms, presents a significant threat to global health care. This critical situation underscores the urgent need for the discovery and development of antimicrobial agents. Recently, peptide-derived antimicrobial nanomaterials have shown promise in combating such infections. Amino acid noncovalent forces, notably π–π stacking and electrostatic interactions, remain underutilized for guiding the coassembly of peptides into bacteriostatic nanomaterials. Thus, we constructed a dimeric nanopeptide system using the disulfide bonds of cysteine. The self-assembly of dimeric peptides into nanofibers was realized by the interaction of π–π aromatic amino acids (Trp, Phe, and Pyr) and the electrostatic attraction between oppositely charged amino acids (Asp and Arg). The optimal dimeric peptide 2D2W exhibits potent antibacterial activity against resistant bacteria and is nontoxic. Mechanistically, 2D2W penetrated the outer membrane after electrostatic adsorption, resulting in plasma membrane depolarization, homeostatic disruption, and ultimately bacterial death. In a mouse model of peritonitis, 2D2W demonstrated efficacy in the in vivo treatment of bacterial infections. In conclusion, the design of dimeric nanopeptides co-driven by intermolecular forces provides a promising avenue for the development of high-performance antimicrobial nanomaterials. These advances may also facilitate the application and advancement of peptide-based bacteriostatic agents in clinical practice.
Robotic Microcapsule Assemblies with Adaptive Mobility for Targeted Treatment of Rugged Biological Microenvironments
Hong Huy Tran - ,
Zhenting Xiang - ,
Min Jun Oh - ,
Yuan Liu - ,
Zhi Ren - ,
Chider Chen - ,
Nadasinee Jaruchotiratanasakul - ,
James M. Kikkawa - ,
Daeyeon Lee *- ,
Hyun Koo *- , and
Edward Steager *
This publication is Open Access under the license indicated. Learn More
Microrobots are poised to transform biomedicine by enabling precise, noninvasive procedures. However, current magnetic microrobots, composed of solid monolithic particles, present fundamental challenges in engineering intersubunit interactions, limiting their collective effectiveness in navigating irregular biological terrains and confined spaces. To address this, we design hierarchically assembled microrobots with multiaxis mobility and collective adaptability by engineering the potential magnetic interaction energy between subunits to create stable, self-reconfigurable structures capable of carrying and protecting cargo internally. Using double emulsion templates and magnetic control techniques, we confine 10 nm iron oxide and 15 nm silica nanoparticles within the shell of 100 μm microcapsules that form multiunit robotic collectives. Unexpectedly, we find that asymmetric localization of iron oxide nanoparticles in the microcapsules enhances the intercapsule potential energy, creating stable connections under rotating magnetic fields without altering the magnetic susceptibility. These robotic microcapsule collectives exhibit emergent behaviors, self-reconfiguring into kinematic chain-like structures to traverse complex obstacles, arched confinements, and adhesive, rugged biological tissues that typically impede microscale systems. By harnessing these functions, we demonstrate targeted antifungal delivery using a localized biofilm model on mucosal tissues, showing effective killing ofCandida without binding or causing physical damage to host cells. Our findings show how hierarchical assembly can produce cargo-carrying microrobots with collective, self-adaptive mobility for traversing complex biological environments, advancing targeted delivery for biomedical applications.
Mitigating the Efficiency Deficit in Single-Crystal Perovskite Solar Cells by Precise Control of the Growth Processes
Tongpeng Zhao - ,
Ruiqin He - ,
Tanghao Liu *- ,
Yanhao Li - ,
De Yu - ,
Yuxin Gao - ,
Geyang Qu - ,
Ning Li - ,
Chunmei Wang - ,
Huang Huang - ,
Jiong Zhou - ,
Sai Bai - ,
Shumin Xiao - ,
Zhaolai Chen - ,
Yimu Chen *- , and
Qinghai Song *
The power conversion efficiencies (PCEs) of polycrystalline perovskite solar cells (PC–PSCs) have now reached a plateau after a decade of rapid development, leaving a distinct gap from their Shockley-Queisser limit. To continuously mitigate the PCE deficit, nonradiative carrier losses resulting from defects should be further optimized. Single-crystal perovskites are considered an ideal platform to study the efficiency limit of perovskite solar cells due to their intrinsically low defect density, as demonstrated in bulk single crystals. However, current single-crystal perovskite solar cells (SC-PSCs) based on single-crystal thin film (SCTF) suffer from severe nonradiative carrier losses at the interface and in the bulk simultaneously due to the immature SCTF growth techniques. In this study, we show that the SC-PSCs can outperform state-of-the-art PC–PSCs, with MAPbI3 as an example, by suppressing carrier losses at the interface and in the bulk in device-compatible SCTFs through precisely controlling their growth.
Rapid Preparation of Collagen/Red Blood Cell Membrane Tubes for Stenosis-Free Vascular Regeneration
Chunliang Zhang - ,
Chunyuan Wang - ,
Ruitao Cha *- ,
Qinghua Meng - ,
Zhan Hu - ,
Yang Sun - ,
Zulan Li - ,
Min Xiao *- ,
Yan Zhang *- , and
Xingyu Jiang *
Extracellular matrix (ECM)-based small-diameter vascular grafts (SDVGs, inner diameter (ID) < 6 mm) hold great promise for clinical applications. However, existing ECM-based SDVGs suffer from limited donor availability, complex purification, high cost, and insufficient mechanical properties. SDVGs with ECM-like structure and function, and good mechanical properties were rapidly prepared by optimizing common materials and preparation, which can improve their clinical prospects. Here, we rapidly prepared an electrospinning film-collagen/red blood cell membrane-genipin hydrogel tube (ES-C/Rm-G-ht, ID = 2 mm) by the combination of the cross-linking of genipin, plastic compression, electrospinning, and rolling without a biological adhesive, which had a shorter preparation time of less than 17 h compared to the existing ECM-based SDVGs (preparation time of 4–18 weeks). ES-C/Rm-G-ht exhibited a layered honeycomb-like structure and demonstrated the ECM-like functions to promote the proliferation and migration of endothelial cells, and prevent thrombus and inflammation. Furthermore, ES-C/Rm-G-ht, possessing sufficient mechanical strength, showed high patency, rapid endothelialization (95%), good regeneration of smooth muscle cell layers and ECM, and effective antistenosis capability after implantation in the rabbit’s carotid artery for 31 days. This work provides a straightforward, cost-effective, and promising strategy to prepare SDVGs with ECM-like structure and function, which is an ideal alternative for vascular grafts and autologous vessels in the current clinic.
Photoinduced Fröhlich Interaction-Driven Distinct Electron- and Hole-Polaron Behaviors in Hybrid Organic–Inorganic Perovskites by Ultrafast Terahertz Probes
Yuna Song - ,
Zhongtao Duan - ,
Lei Peng - ,
Juan Zhang - ,
Xun Zhu - ,
Qi Feng - ,
Zhihao Ji - ,
Yuqing Zou - ,
Jingying Zhang - ,
Ziyang Li - ,
Zongzhi Zhang - ,
Xiao-Lei Zhang - ,
Fengxian Xie *- ,
Hao Zhang *- , and
Qingyuan Jin *
The formation of large polarons resulting from the Fröhlich coupling of photogenerated carriers with the polarized crystal lattice is considered crucial in shaping the outstanding optoelectronic properties in hybrid organic–inorganic perovskite crystals. Until now, the initial polaron dynamics after photoexcitation have remained elusive in the hybrid perovskite system. Here, based on the terahertz time-domain spectroscopy and optical-pump terahertz probe, we access the nature of interplay between photoexcited unbound charge carriers and optical phonons in MAPbBr3 within the initial 5 ps after excitation and have demonstrated the simultaneous existence of both electron- and hole-polarons, together with the photogenerated carrier dynamic process. Two resonant peaks in the frequency-dependent photoconductivity are interpreted by the Drude–Smith–Lorentz model along with the ab initio excitation calculation, revealing that the electron-/hole-polaron is related to the vibration modes of the stretched/contracted Pb–Br bond. The red /blue shift of the corresponding peaks as the fingerprints of electron-/hole-polaron provides a channel for observing their dynamic behavior. Different from polarons with long lifetime (>300 ps) in single-crystalline grains, we observed in thin films the transient process from the formation to the dissociation of polarons occurring at timescales within ∼5 ps, resulting from the Mott phase transition for carriers at high concentrations. Moreover, the observation of the polaron dynamic process of the virtual state-assisted band gap transition (800 nm excitation) further reveals the competition of carriers cooling and polaron formation with photocarrier density. Our observations demonstrate a strategy for direct observation and manipulation of bipolar polaron transport in hybrid perovskites.
Individual Assembly of Radical Molecules on Superconductors: Demonstrating Quantum Spin Behavior and Bistable Charge Rearrangement
Chao Li *- ,
Vladislav Pokorný - ,
Martin Žonda *- ,
Jung-Ching Liu - ,
Ping Zhou - ,
Outhmane Chahib - ,
Thilo Glatzel - ,
Robert Häner - ,
Silvio Decurtins - ,
Shi-Xia Liu *- ,
Rémy Pawlak *- , and
Ernst Meyer *
This publication is Open Access under the license indicated. Learn More
High-precision molecular manipulation techniques are used to control the distance between radical molecules on superconductors. Our results show that the molecules can host single electrons with a spin 1/2. By changing the distance between tip and sample, a quantum phase transition from the singlet to doublet ground state can be induced. Due to local screening and charge redistribution, we observe either charged or neutral molecules, which couple in a sophisticated way, showing quantum spin behavior that deviates from the classical spins. Dimers at different separations show multiple Yu-Shiba-Rusinov peaks in tunneling spectroscopy of varying intensity, which are in line with the superconducting two-impurity Anderson model, where singlet (S = 0) and doublet (S = 1/2) ground states are found. The assembly of chains of 3, 4, and 5 molecules shows alternating charge patterns, where the edge molecules always host a charge/spin. The tetramer is observed in two configurations, where the neutral site is moved by one position. We show that these two configurations can be switched by the action of the probing tip in a nondestructive manner, demonstrating that the tetramer is an information unit, based on single-electron charge reorganization.
Two-Dimensional Nonvolatile Valley Spin Valve
Kai Huang - ,
Kartik Samanta - ,
Ding-Fu Shao - , and
Evgeny Y. Tsymbal *
A spin valve represents a well-established device concept in magnetic memory technologies, whose functionality is determined by electron transmission, controlled by the relative alignment of magnetic moments of the two ferromagnetic layers. Recently, the advent of valleytronics has conceptualized a valley spin valve (VSV)─a device that utilizes the valley degree of freedom and spin-valley locking to achieve a similar valve effect without relying on magnetism. In this study, we propose a nonvolatile VSV (n-VSV) based on a two-dimensional (2D) ferroelectric semiconductor where resistance of n-VSV is controlled by a ferroelectric domain wall between two uniformly polarized domains. Focusing on the 1T″ phase of MoS2, which is known to be ferroelectric down to a monolayer and using density functional theory combined with quantum transport calculations, we demonstrate that switching between the uniformly polarized state and the state with oppositely polarized domains separated by a domain wall results in a resistance change of as high as 107. This giant VSV effect occurs due to transmission being strongly dependent on matching (mismatching) the valley-dependent spin polarization in the two domains with the same (opposite) ferroelectric polarization orientations, when the chemical potential of 1T″-MoS2 lies within the spin-split valleys. The proposed n-VSV can be employed as a functional device for high-performance nonvolatile valleytronics.
Pick-and-Place Transfer of Arbitrary-Metal Electrodes for van der Waals Device Fabrication
Kaijian Xing *- ,
Daniel McEwen - ,
Yuefeng Yin - ,
Weiyao Zhao - ,
Abdulhakim Bake - ,
David Cortie - ,
Jingying Liu - ,
Thi-Hai-Yen Vu - ,
Yi-Hsun Chen - ,
James Hone - ,
Alastair Stacey - ,
Mark T. Edmonds - ,
Nikhil V. Medhekar - ,
Kenji Watanabe - ,
Takashi Taniguchi - ,
Qingdong Ou *- ,
Dong-Chen Qi *- , and
Michael S. Fuhrer *
Van der Waals electrode integration is a promising strategy to create nearly perfect interfaces between metals and 2D materials, with advantages such as eliminating Fermi-level pinning and reducing contact resistance. However, the lack of a simple, generalizable pick-and-place transfer technology has greatly hampered the wide use of this technique. We demonstrate the pick-and-place transfer of prefabricated electrodes from reusable polished hydrogenated diamond substrates without the use of any sacrificial layers due to the inherent low-energy and dangling-bond-free nature of the hydrogenated diamond surface. The technique enables transfer of arbitrary-metal electrodes and an electrode array, as demonstrated by successful transfer of eight different elemental metals with work functions ranging from 4.22 to 5.65 eV. We also demonstrate the electrode array transfer for large-scale device fabrication. The mechanical transfer of metal electrodes from diamond to van der Waals materials creates atomically smooth interfaces with no interstitial impurities or disorder, as observed with cross-section high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. As a demonstration of its device application, we use the diamond transfer technique to create metal contacts to monolayer transition metal dichalcogenide semiconductors with high-work-function Pd, low-work-function Ti, and semimetal Bi to create n- and p-type field-effect transistors with low Schottky barrier heights. We also extend this technology to air-sensitive materials (trilayer 1T’ WTe2) and other applications such as ambipolar transistors, Schottky diodes, and optoelectronics. This highly reliable and reproducible technology paves the way for new device architectures and high-performance devices.
Active Inference and Artificial Spin Ice: Control Processes and State Selection
Robert L. Stamps *- ,
Rehana Begum Popy - , and
Johan van Lierop *
Theory and simulations are used to demonstrate implementation of a variational Bayes algorithm called “active inference” in interacting arrays of nanomagnetic elements. The algorithm requires stochastic elements, and a simplified model based on a magnetic artificial spin ice geometry is used to illustrate how nanomagnets can generate the required random dynamics. Examples of tracking and PID control are demonstrated and shown to be consistent with the original stochastic differential equation formulation of active inference. Interestingly, nonlinear response in the form of spikes and spike trains not predicted by the original theory can appear in the nanomagnet system for certain temperature regimes. A theoretical approach using a mean-field approximation for spin systems is proposed, which describes the transition to nonlinear response. Finally, the possibility to create simple magnetic arrays using realistic models is shown with micromagnetic simulations of a simple 17 element array of nanomagnets that include magnetic anisotropies, and exchange and dipolar interactions. Possible applications are simulated to illustrate how nanomagnetic arrays can be used as the stochastic element for feedback control of processes, investigation and control of magnetic state evolution, and as a method to optimize pulsed field magnetic switching protocols.
Atomically Precise Fabrication of Ultranarrow Zigzag CuTe Nanoribbons via Dimensional Regulation
Gefei Niu - ,
Jianchen Lu *- ,
Lei Gao *- ,
Jianqun Geng - ,
Wei Xiong - ,
Yong Zhang - ,
Hui Zhang - ,
Shicheng Li - ,
Yuhang Yang - ,
Boyu Fu - ,
Yi Zhang - , and
Jinming Cai *
Artificial dimension control has been playing a vital role in electronic structure manipulation and properties generation. However, systematic investigations into the dimensional regulation, such as transformation from two-dimensional (2D) materials to well-controlled one-dimensional (1D) ribbons, remain insufficient via molecular beam epitaxy. Here, high-quality ultranarrow zigzag CuTe nanoribbons are atomically precisely prepared via the dimensional regulation induced by adjusting the Te chemical potential, utilizing CuSe monolayer as the starting 2D template. Introducing Te atoms into the CuSe monolayer and subsequent annealing, Te atoms replace Se atoms within CuSe lattice. As the Te substitution ratio increases, strain accumulates and elongated nanopores emerge, which expand and interconnect to form 1D CuSe1–xTex (0 ≤ x ≤ 1) nanoribbons and ultimately coalesce into a 1D ultranarrow zigzag CuTe nanoribbons with a honeycomb lattice. The entire structural transformation is verified through scanning tunneling microscopy (STM) and density functional theory (DFT). Contrary to the 2D semiconducting nature of CuSe and CuSe1–xTex monolayers, newly formed 1D CuTe nanoribbons exhibit metallic properties. Intriguingly, DFT calculations further reveal spin-polarized states at the zigzag edges of CuTe nanoribbons. Our proposed dimensional regulation strategy from 2D materials to well-controlled 1D nanoribbons presents avenues for refining and enhancing the synthesis process.
Optical Metasurfaces for Biomedical Imaging and Sensing
Hongyoon Kim - ,
Heechang Yun - ,
Sebin Jeong - ,
Seokho Lee - ,
Eunseo Cho - , and
Junsuk Rho *
Optical metasurfaces, arrays of nanostructures engineered to manipulate light, have emerged as a transformative technology in both research and industry due to their compact design and exceptional light control capabilities. Their strong light–matter interactions enable precise wavefront modulation, polarization control, and significant near-field enhancements. These unique properties have recently driven their application in biomedical fields. In particular, metasurfaces have led to breakthroughs in biomedical imaging technologies, such as achromatic imaging, phase imaging, and extended depth-of-focus imaging. They have also advanced cutting-edge biosensing technologies, featuring high-quality factor resonators and near-field enhancements. As the demand for device miniaturization and system integration increases, metasurfaces are expected to play a pivotal role in the development of next-generation biomedical devices. In this review, we explore the latest advancements in the use of metasurfaces for biomedical applications, with a particular focus on imaging and sensing. Additionally, we discuss future directions aimed at transforming the biomedical field by leveraging the full potential of metasurfaces to provide compact, high-performance solutions for a wide range of applications.
Volatile Sieving Using Architecturally Designed Nanochannel Lamellar Membranes in Membrane Desalination
Zhigao Zhu - ,
Xiaohui Wang - ,
Yujun Zhou - ,
Junwen Qi - ,
Yue Yang - ,
Wei Wang *- , and
Jiansheng Li *
Thermally driven membrane desalination processes have garnered significant interest for their potential in the treatment of hypersaline wastewater. However, achieving high rejection rates for volatiles while maintaining a high water flux remains a considerable challenge. Herein, we propose a thermo-osmosis-evaporation (TOE) system that utilizes molecular intercalation-regulated graphene oxide (GO) as the thermo-osmotic selective permeation layer, positioned on a hydrophobic poly(vinylidene fluoride) fibrous membrane serving as the thermo-evaporation layer. By carefully constructing architectural interlaminar nanochannels of GO membranes via simultaneously confining small molecules to enlarge the interlayer spacing and incorporating polymers within the GO interlayers to create a dense network, the resultant demonstrates a rejection rate of 100% for NaCl and 97.41% for volatile phenylamine, with a water permeance of 63.80 L m–2 h–1 at a temperature difference of 40 °C, outperforming previously reported GO-based membranes. Simulation and calculation results reveal that the polymer network between the GO interlayers facilitates the high-efficiency separation of nonvolatile ions and volatile molecules, while the enlarged channels reduce vapor diffusion resistance. This study provides valuable insights for the design of advanced membranes and serves as inspiration for the continued development of the TOE system for complex hypersaline wastewater treatment.
Bionic Luminescent Sensors Based on Covalent Organic Frameworks: Auditory, Gustatory, and Olfactory Information Monitoring for Multimode Perception
Xueping Quan - ,
Kai Zhu - ,
Yinsheng Liu - , and
Bing Yan *
The synthesis of covalent organic frameworks (COFs) with excellent luminescent properties and their effective application in the field of bionic sensing remain a formidable challenge. Herein, a series of COFs with different numbers of hydroxyl groups are successfully synthesized, and the number of hydroxyl groups on the benzene-1,3,5-tricarbaldehyde (BTA) linker influences the properties of the final COFs. The COF (HHBTA-OH) prepared with hydrazine hydrate (HH) and BTA containing one hydroxyl group as the ligands exhibits the best fluorescent performance. MA@HHBTA-OH is formed by the reaction of HHBTA-OH with meldrum’s acid (MA) and has its extremely high hydrophilicity, dispersibility, and strong red fluorescence, which can imitate the human gustatory system to detect bitter substances. MA@HHBTA-OH was combined with agarose (AG) to construct a MA@HHBTA-OH@AG film for assessing food freshness. In addition, an acoustic MA@HHBTA-OH@MF sensor is fabricated by integrating luminescent MA@HHBTA-OH with melamine foam (MF) through a strong hydrogen bond. MA@HHBTA-OH@MF functions like an eardrum and recognizes sound through pressure waves with excellent mechanical sensing performance. In summary, biomimetic luminescent sensors based on MA@HHBTA-OH were successfully constructed, which can monitor auditory, gustatory, and olfactory information to achieve the multimode perception of sound, bitter substances, and food freshness.
Superconductive Coupling Effects in Selectively Grown Topological Insulator-Based Three-Terminal Junctions
Gerrit Behner *- ,
Abdur Rehman Jalil - ,
Alina Rupp - ,
Hans Lüth - ,
Detlev Grützmacher - , and
Thomas Schäpers *
This publication is Open Access under the license indicated. Learn More
The combination of an ordinary s-type superconductor with three-dimensional topological insulators creates a promising platform for fault-tolerant topological quantum computing circuits based on Majorana braiding. The backbone of the braiding mechanism are three-terminal Josephson junctions. It is crucial to understand the transport in these devices for further use in quantum computing applications. We present low-temperature measurements of topological insulator-based three-terminal Josephson junctions fabricated by a combination of selective-area growth of Bi0.8Sb1.2Te3 and shadow mask evaporation of Nb. This approach allows for the in situ fabrication of Josephson junctions with an exceptional interface quality, important for the study of the proximity-effect. We map out the transport properties of the device as a function of bias currents and prove the coupling of the junctions by the observation of a multiterminal geometry-induced diode effect. We find good agreement of our findings with a resistively and capacitively shunted junction network model.
Controlled Nitrogen Release by Hydroxyapatite Nanomaterials in Leaves Enhances Plant Growth and Nitrogen Uptake
Bhaskar Sharma - ,
Hagay Kohay - ,
Sandeep Sharma - ,
Marina Youngblood - ,
Jarad P. Cochran - ,
Jason M. Unrine - ,
Olga V. Tsyusko - ,
Gregory V. Lowry - , and
Juan Pablo Giraldo *
Nitrogen fertilizer delivery inefficiencies limit crop productivity and contribute to environmental pollution. Herein, we developed Zn- and Fe-doped hydroxyapatite nanomaterials (ZnHAU, FeHAU) loaded with urea (∼26% N) through hydrogen bonding and metal–ligand interactions. The nanomaterials attach to the leaf epidermal cuticle and localize in the apoplast of leaf epidermal cells, triggering a slow N release at acidic conditions (pH 5.8) that promote wheat (Triticum aestivum) growth and increased N uptake compared to conventional urea fertilizers. ZnHAU and FeHAU exhibited prolonged N release compared to urea in model plant apoplast fluid pH in vitro (up to 2 days) and in leaf membranes in plants (up to 10 days) with a high N retention (32% to 53%) under simulated high rainfall events (50 mm). Foliar N delivery doses of up to 4% as ZnHAU and FeHAU did not induce toxicity in plant cells. The foliar-applied ZnHAU and FeHAU enhanced fresh and dry biomass by ∼214% and ∼161%, and N uptake by ∼108% compared to foliar-applied urea under low soil N conditions in greenhouse experiments. Controlled N release by leaf-attached nanomaterials improves N delivery and use efficiency in crop plants, creating nanofertilizers with reduced environmental impact.
Preclinical and First-in-Human Study of a Compact Radionuclide Labeled Self-Assembly Nanomedicine for Chemo-Radio-Theranostics of Cancer
Hehe Xiong - ,
Rongxi Wang - ,
Heng Zhang - ,
Qianyu Zhang - ,
Yatong Qin - ,
Chao Du - ,
Xinyi Zhang - ,
Jinmin Ye - ,
Changrong Shi - ,
Huaxiang Shen - ,
Zhaohui Zhu *- ,
Zijian Zhou *- ,
Xiaoyuan Chen *- , and
Jingjing Zhang *
The emerging combination of chemotherapy and radionuclide therapy has been actively investigated to overcome the limitations of monotherapy and augment therapeutic efficacy. However, it remains a challenge to design a single delivery vehicle that can incorporate chemotherapeutics and radionuclides into a compact structure. Here, a chelator DOTA- or NOTA-modified Evans blue conjugated camptothecin molecule (EB-CPT) nanoprodrug was synthesized, which could self-assemble into nanoparticles due to its inherent amphiphilicity. The nanoparticles could then be effectively labeled with therapeutic radionuclide lutetium-177 (177Lu) or diagnostic radionuclides gallium-68 (68Ga)/copper-64 (64Cu) with high radiolabeling efficiency and radiochemical stability. Impressively, a single-dose chemoradiation therapy of [177Lu]Lu-DOTA-EB-CPT plus EB-CPT effectively inhibited tumor growth in HCT116 tumor-bearing mice compared to the respective individual therapeutic approach. The [64Cu]Cu-NOTA-EB-CPT nanoparticles also exhibited excellent in vivo characteristics including favorable blood circulation properties and prolonged tumor retention in tumor-bearing mice. The safety, feasibility, tolerability, and biodistribution of [68Ga]Ga-NOTA-EB-ss-CPT were also preliminarily characterized in a first-in-human study. This study presents a simple but robust EB-CPT radiopharmaceutical that leverages EB as an albumin binder to strike a delicate balance between enhanced tumor accumulation, safety, and diagnostic efficacy, facilitating an integrated theranostic strategy within a single molecular structure. This radionuclide-labeled EB-CPT nanomedicine presents a step toward clinical translation of the combination of chemotherapy and radiotheranostics.
January 12, 2025
Permeable, Stretchable, and Recyclable Cellulose Aerogel On-Skin Electronics for Dual-Modal Sensing and Personal Healthcare
Shuai Liu - ,
Wenwen Li - ,
Xinyi Wang - ,
Liang Lu *- ,
Yue Yao - ,
Shuyu Lai - ,
Yunqi Xu - ,
Junjie Yang - ,
Zhihao Hu - ,
Xinglong Gong *- ,
Ken Cham-Fai Leung - , and
Shouhu Xuan *
Flexible on-skin electronics present tremendous popularity in intelligent electronic skins (e-skins), healthcare monitoring, and human-machine interfaces. However, the reported e-skins can hardly provide high permeability, good stretchability, and large sensitivity and are limited in long-term stability and efficient recyclability when worn on the human body. Herein, inspired from the human skin, a permeable, stretchable, and recyclable cellulose aerogel-based electronic system is developed by sandwiching a screen-printed silver sensing layer between a biocompatible CNF/HPC/PVA (cellulose nanofiber/hydroxypropyl cellulose/poly(vinyl alcohol)) aerogel hypodermis layer and a permeable polyurethane layer as the epidermis layer. The cellulose aerogel displays a high tensile strength of 1.14 MPa and tensile strain of 43.5% while maintaining good permeability. The cellulose aerogel-based electronics embrace appealing sensing performances with high sensitivity (gauge factor ≈ 238), ultralow detection limit (0.1%), and fast response time (18 ms) under strain stimulus. Owing to the disconnection and reconnection of microcracks in the sensing layer, both strain/humidity sensing and thermal healthcare can be easily achieved. The permeable electronics can be further integrated into an electronic mask for patient-centered healthcare with a power supply system, switching control device, and wireless Bluetooth module. Moreover, the prepared electronic system enables long-term wearing on human skin without skin irritation, and all components of the electronics can be recaptured/reused in water. This material strategy highlights the potential of next-generation on-skin electronics with high permeability and good environmental friendliness.
van der Waals Photonic Bipolar Junction Transistors Capable of Simultaneously Discerning Wavelength Bands and Dual-Function Chip Application
Zhengrui Zhu - ,
Liwei Liu - ,
Shaozhi Deng *- , and
Ningsheng Xu *
The exponential growth of the Internet of Things (IoTs) has led to the widespread deployment of millions of sensors, crucial for the sensing layer’s perception capabilities. In particular, there is a strong interest in intelligent photonic sensing. However, the current photonic sensing device and chip typically offer limited functionality, and the devices providing their power take up excessive amounts of space. There is a pressing need for smart, multifunctional sensing chips with the capability of intelligent recognition. Here, we propose and demonstrate the functionalities of a two-dimensional van der Waals photonic bipolar junction transistor (2D-vdW photonic BJT) in simultaneous sensing and discerning different wavelength bands of light. Also, a dual-function chip application is given. The optoelectronic detection characteristics in the vision-near-infrared (vis-NIR) band and photovoltaic characteristics are systematically studied. It exhibits negative photoconductivity (NPC) for the 1064 nm laser while maintaining positive photoconductivity (PPC) for the 638 and 1550 nm lasers. Also, the electrical tunable response is realized. Moreover, the function of this chip under real-application conditions has shown its efficacy in applications such as detecting dim light with ∼10 lx illuminance, identifying wavelength bands, and generating power photovoltaically. This work provides a solution for the interconnection of everything.
Temperature-Directed Morphology Transformation Method for Precision-Engineered Polymer Nanostructures
Valentin A. Bobrin *- ,
Surya E. Sharma-Brymer - , and
Michael J. Monteiro *
With polymer nanoparticles now playing an influential role in biological applications, the synthesis of nanoparticles with precise control over size, shape, and chemical functionality, along with a responsive ability to environmental changes, remains a significant challenge. To address this challenge, innovative polymerization methods must be developed that can incorporate diverse functional groups and stimuli-responsive moieties into polymer nanostructures, which can then be tailored for specific biological applications. By combining the advantages of emulsion polymerization in an environmentally friendly reaction medium, high polymerization rates due to the compartmentalization effect, chemical functionality, and scalability, with the precise control over polymer chain growth achieved through reversible-deactivation radical polymerization, our group developed the temperature-directed morphology transformation (TDMT) method to produce polymer nanoparticles. This method utilized temperature or pH responsive nanoreactors for controlled particle growth and with the added advantages of controlled surface chemical functionality and the ability to produce well-defined asymmetric structures (e.g., tadpoles and kettlebells). This review summarizes the fundamental thermodynamic and kinetic principles that govern particle formation and control using the TDMT method, allowing precision-engineered polymer nanoparticles, offering a versatile and an efficient means to produce 3D nanostructures directly in water with diverse morphologies, high purity, high solids content, and controlled surface and internal functionality. With such control over the nanoparticle features, the TDMT-generated nanostructures could be designed for a wide variety of biological applications, including antiviral coatings effective against SARS-CoV-2 and other pathogens, reversible scaffolds for stem cell expansion and release, and vaccine and drug delivery systems.
Dual Strategies Based on Golgi Apparatus/Endoplasmic Reticulum Targeting and Anchoring for High-Efficiency siRNA Delivery and Tumor RNAi Therapy
Yashi Wang - ,
Sheng Yin - ,
Dan He - ,
Yujia Zhang - ,
Ziyan Dong - ,
Zhipeng Tian - ,
Jiayu Li - ,
Fang Chen - ,
Yang Wang - ,
Man Li *- , and
Qin He *
Endolysosomal degradation of small interfering RNA (siRNA) significantly reduces the efficacy of RNA interference (RNAi) delivered by nonviral systems. Leveraging Golgi apparatus/endoplasmic reticulum (Golgi/ER) transport can help siRNA bypass the endolysosomal degradation pathway, but this approach may also result in insufficient siRNA release and an increased risk of Golgi/ER-mediated exocytosis. To address these challenges, we developed two distinct strategies using a nanocomplex of cell-penetrating poly(disulfide)s and chondroitin sulfate, which enhances targeted internalization, Golgi transport, and rapid cytoplasmic release of loaded siRNA. In the first strategy, monensin synergy was found to enhance RNAi by inhibiting both exocytosis and autophagic degradation. In the second strategy, a “directed sorting” approach based on KDEL peptide-mediated retrograde transport was introduced. By conjugation of the KDEL peptide to chondroitin sulfate, Golgi-to-ER transport was promoted, reducing “random” Golgi/ER-related exocytosis. These two strategies operate alternatively to achieve high-efficiency RNAi with a significant therapeutic potential. Notably, in a mouse melanoma model using anti-Bcl-2 siRNA, the strategies achieved tumor inhibition rates of 87.1 and 90.1%, respectively. These two strategies, based on “targeting” and “anchoring” Golgi/ER, provide potent solutions to overcome the challenges of cellular internalization, intracellular release, and exocytosis in efficient siRNA delivery.
January 11, 2025
Giant Purcell Broadening and Lamb Shift for DNA-Assembled Near-Infrared Quantum Emitters
Sachin Verlekar - ,
Maria Sanz-Paz - ,
Mario Zapata-Herrera - ,
Mauricio Pilo-Pais - ,
Karol Kołątaj - ,
Ruben Esteban *- ,
Javier Aizpurua - ,
Guillermo P. Acuna *- , and
Christophe Galland *
Controlling the light emitted by individual molecules is instrumental to a number of advanced nanotechnologies ranging from super-resolution bioimaging and molecular sensing to quantum nanophotonics. Molecular emission can be tailored by modifying the local photonic environment, for example, by precisely placing a single molecule inside a plasmonic nanocavity with the help of DNA origami. Here, using this scalable approach, we show that commercial fluorophores may experience giant Purcell factors and Lamb shifts, reaching values on par with those recently reported in scanning tip experiments. Engineering of plasmonic modes enables cavity-mediated fluorescence far detuned from the zero-phonon-line (ZPL)─at detunings that are up to 2 orders of magnitude larger than the fluorescence line width of the bare emitter and reach into the near-infrared. Our results point toward a regime where the emission line width can become dominated by the excited-state lifetime, as required for indistinguishable photon emission, bearing relevance to the development of nanoscale, ultrafast quantum light sources and to the quest toward single-molecule cavity QED. In the future, this approach may also allow the design of efficient quantum emitters at infrared wavelengths, where standard organic sources have a reduced performance.
Rational Design of Dual-Targeted Nanomedicines for Enhanced Vascular Permeability in Low-Permeability Tumors
Mingsheng Zhu - ,
Qiqi Liu - ,
Zhengbang Chen - ,
Jinming Liu - ,
Zhixuan Zhang - ,
Jingwei Tian - ,
Xiangyang Wang - ,
Xiong Yang - ,
Quan Chen - ,
Xinglu Huang *- , and
Jie Zhuang *
Designing dual-targeted nanomedicines to enhance tumor delivery efficacy is a complex challenge, largely due to the barrier posed by blood vessels during systemic delivery. Effective transport across endothelial cells is, therefore, a critical topic of study. Herein, we present a synthetic biology-based approach to engineer dual-targeted ferritin nanocages (Dt-FTn) for understanding receptor-mediated transport across tumor endothelial cells. By leveraging a genetically engineered logic-gated strategy, we coassembled various Dt-FTn in E. coli with tunable ratios of RGD-targeting and intrinsic TfR1-targeting ligands. These Dt-FTn constructs were employed to investigate the interaction between receptor-mediated vascular permeability and dual-targeted nanomedicines in low-permeability tumors. Through machine learning-based single vessel analysis, we uncovered the crucial role of dual-receptor expression profiles in determining the vascular transport of dual-targeted nanomedicines in tumors with low permeability. Using a patient-derived colon cancer model, we demonstrated a proof-of-concept that the optimal proportions of dual ligands in these nanomedicines can be customized based on tumor cell receptor expression profiles. This study provides valuable insights and guiding principles for the rational design of dual-targeted nanomedicines for tumor-targeted delivery.
Shaping the Emission Directivity of Single Quantum Dots in Dielectric Nanodisks Exploiting Mie Resonances
Cristina Cruciano - ,
Davide Rocco - ,
Armando Genco *- ,
Andrea Tognazzi - ,
Andrea Locatelli - ,
Luca Carletti - ,
Alexey Fedorov - ,
Chiara Trovatello - ,
Giuseppe Di Blasio - ,
Ilaria Bargigia - ,
Charalambos Louca - ,
Paolo Gubian - ,
Giulio Tavani - ,
Luca Lovisolo - ,
Artur Tuktamyshev - ,
Lucio C. Andreani - ,
Matteo Galli - ,
Giulio Cerullo - ,
Giuseppe Leo - ,
Stefano Sanguinetti - ,
Costantino De Angelis - , and
Monica Bollani
Manipulating the optical landscape of single quantum dots (QDs) is essential to increase the emitted photon output, enhancing their performance as chemical sensors and single-photon sources. Micro-optical structures are typically used for this task, with the drawback of a large size compared to the embedded single emitters. Nanophotonic architectures hold the promise to modify dramatically the emission properties of QDs, boosting light–matter interactions at the nanoscale, in ultracompact devices. Here, we investigate the interplay between gallium arsenide (GaAs) single QDs and aluminum gallium arsenide (AlGaAs) nanostructures, capitalizing on the Kerker condition for precise control of the QD emission directivity. An extensive analysis of the photoluminescence spectra of several QDs embedded in nanodisks revealed a pronounced directivity enhancement due to the Kerker effect, confirmed by theoretical simulations, resulting in a 14-fold increase of emitted intensity. Angle-resolved spectroscopy experiments also proved that the integration of GaAs QDs within nanostructures determines a precise angled emission, offering a distinctive avenue for manipulating the spatial characteristics of emitted light by exploiting Mie resonances. This work contributes to the optimization of QD integration in nanostructures and suggests potential improvements for applications in optical communications.
Atomic Gap-State Engineering of MoS2 for Alkaline Water and Seawater Splitting
Tao Sun *- ,
Tong Yang - ,
Wenjie Zang - ,
Jing Li - ,
Xiaoyu Sheng - ,
Enzhou Liu - ,
Jiali Li - ,
Xiao Hai - ,
Huihui Lin - ,
Cheng-Hao Chuang - ,
Chenliang Su - ,
Maohong Fan - ,
Ming Yang - ,
Ming Lin - ,
Shibo Xi - ,
Ruqiang Zou *- , and
Jiong Lu *
Transition-metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS2), have emerged as a generation of nonprecious catalysts for the hydrogen evolution reaction (HER), largely due to their theoretical hydrogen adsorption energy close to that of platinum. However, efforts to activate the basal planes of TMDs have primarily centered around strategies such as introducing numerous atomic vacancies, creating vacancy–heteroatom complexes, or applying significant strain, especially for acidic media. These approaches, while potentially effective, present substantial challenges in practical large-scale deployment. Here, we report a gap-state engineering strategy for the controlled activation of S atom in MoS2 basal planes through metal single-atom doping, effectively tackling both efficiency and stability challenges in alkaline water and seawater splitting. A versatile synthetic methodology allows for the fabrication of a series of single-metal atom-doped MoS2 materials (M1/MoS2), featuring widely tunable densities with each dopant replacing a Mo site. Among these (Mn1, Fe1, Co1, and Ni1), Co1/MoS2 demonstrates outstanding HER performance in both alkaline and seawater alkaline media, with overpotentials at a mere 159 and 164 mV at 100 mA cm–2, and Tafel slopes at 41 and 45 mV dec–1, respectively, which surpasses all reported TMD-based nonprecious materials and benchmark Pt/C catalysts in HER efficiency and stability during seawater splitting, which can be attributed to an optimal gap-state modulation associated with sulfur atoms. Experimental data correlating doping density and dopant identity with HER performance, in conjunction with theoretical calculations, also reveal a descriptor linked to near-Fermi gap state modulation, corroborated by the observed increase in unoccupied S 3p states.
January 10, 2025
Surface Circular Photogalvanic Effect in Tl–Pb Monolayer Alloys on Si(111) with Giant Rashba Splitting
Ibuki Taniuchi - ,
Ryota Akiyama *- ,
Rei Hobara - , and
Shuji Hasegawa
We have found that surface superstructures made of “monolayer alloys” of Tl and Pb on Si(111), having giant Rashba effect, produce nonreciprocal spin-polarized photocurrent via circular photogalvanic effect (CPGE) by obliquely shining circularly polarized near-infrared (IR) light. CPGE is here caused by the injection of in-plane spin into spin-split surface-state bands, which is observed only on Tl–Pb alloy layers but not on single-element Tl nor Pb layers. In the Tl–Pb monolayer alloys, despite their monatomic thickness, the magnitude of CPGE is comparable to or even larger than the cases of many other spin-split thin-film materials. A model analysis has provided the relative permittivity ε* of the monolayer alloys to be ∼1.0, which is because the monolayer exists at a transition region between vacuum and the substrate. The present result opens the possibility that we can optically manipulate the spins of electrons even on monolayer materials.
Dual-Anion-Rich Polymer Electrolytes for High-Voltage Solid-State Lithium Metal Batteries
Yangqian Zhang - ,
Han Liu - ,
Fangyan Liu - ,
Shuoxiao Zhang - ,
Mengyuan Zhou - ,
Yaqi Liao - ,
Ying Wei - ,
Weixia Dong - ,
Tianyi Li - ,
Chen Liu *- ,
Qi Liu - ,
Henghui Xu - ,
Gang Sun - ,
Zhenbo Wang - ,
Yang Ren *- , and
Jiayi Yang *
Solid polymer electrolytes (SPEs) are promising candidates for lithium metal batteries (LMBs) owing to their safety features and compatibility with lithium metal anodes. However, the inferior ionic conductivity and electrochemical stability of SPEs hinder their application in high-voltage solid-state LMBs (HVSSLMBs). Here, a strategy is proposed to develop a dual-anion-rich solvation structure by implementing ferroelectric barium titanate (BTO) nanoparticles (NPs) and dual lithium salts into poly(vinylidene fluoride) (PVDF)-based SPEs for HVSSLMBs. The BTO NPs regulate the spatial structure of PVDF segments, enhancing the local built-in electric field in the SPEs, which, in turn, facilitates the dissolution and dissociation of lithium salts. This contributes to the dual-anion-rich solvation structure with an enhanced steric effect, which significantly improves Li+ transport kinetics and electrochemical stability. The designed PVDF-based SPE achieves a high ionic conductivity of 4.1 × 10–4 S cm–1 and a transference number of 0.70 at 25 °C. The Li//Li symmetric cells deliver an excellent critical current density of 2.4 mA cm–2 and maintain a stable Li plating/stripping process for over 5000 h. After 1000 cycles at 2C, the LiFePO4//Li cells achieve a discharge capacity of 108.3 mAh g–1. Furthermore, the LiNi0.8Co0.1Mn0.1O2 (NCM811)//Li cells present high capacity retention after 300 cycles at 1C with a cutoff voltage of 4.4 V. The NCM811/Graphite pouch batteries exhibit excellent cycling and safety performance. This work illustrates that the synergistic integration of functional nanoparticles with multiple lithium salts holds significant potential for the development of high-voltage SPEs.
Vaccine Specifically for Immunocompromised Individuals against Superbugs
Litong Wang - ,
Yitao Zhang - ,
Jiaxin Huang - ,
Sijie Wang - ,
Shuhan Ji - ,
Shenyu Wang - ,
Meixing Shi - ,
Junlei Zhang - ,
Yingying Shi - ,
Zhenyu Luo - ,
Zhaolei Jin - ,
Xindong Jiang - ,
Qingpo Li - ,
Fuchun Yang *- ,
Jian You *- , and
Lihua Luo *
Immunocompromised populations, including cancer patients, elderly individuals, and those with chronic diseases, are the primary targets of superbugs. Traditional vaccines are less effective due to insufficient or impaired immune cells. Inspired by the “vanguard” effect of neutrophils (NE) during natural infection, this project leverages the ability of NE to initiate the NETosis program to recruit monocytes and DC cells, designing vaccines that can rapidly recruit immune cells and enhance the immune response. The PLGA microsphere vaccine platform (MSV) with a high level of safety contains whole-bacterial antigens both internally and externally, providing initial and booster effects through programmed distribution and release of antigens after a single injection. Experimental data indicate that immunizing mice with a mixture of MSV and NE induces the formation of spontaneous gel-like neutrophil extracellular traps (NETs) at the inoculation site. These NETs recruit immune cells and prevent the diffusion of vaccine components, thereby reducing damage from bacterial toxins and enhancing vaccine biosafety. This strategy shows excellent efficacy against MRSA-induced infections in not only healthy but also immunocompromised mice.
High-Resolution Mapping of Photocatalytic Activity by Diffusion-Based and Tunneling Modes of Photo-Scanning Electrochemical Microscopy
Tianyu Bo - ,
Debjit Ghoshal - ,
Logan M. Wilder - ,
Elisa M. Miller *- , and
Michael V. Mirkin *
This publication is Open Access under the license indicated. Learn More
Semiconductor nanomaterials and nanostructured interfaces have important technological applications, ranging from fuel production to electrosynthesis. Their photocatalytic activity is known to be highly heterogeneous, both in an ensemble of nanomaterials and within a single entity. Photoelectrochemical imaging techniques are potentially useful for high-resolution mapping of photo(electro)catalytic active sites; however, the nanoscale spatial resolution required for such experiments has not yet been attained. In this article, we report photoreactivity imaging of two-dimensional MoS2 photocatalysts by two modes of photoscanning electrochemical microscopy (photo-SECM): diffusion and tunneling-based modes. Diffusion-based (feedback mode) photo-SECM is used to map the electron transfer and hydrogen evolution rates on mixed-phase MoS2 nanosheets and MoS2 chemical vapor deposition (CVD)-grown triangles. An extremely high resolution of photoelectrochemical imaging (about 1–2 nm) by the tunneling mode of the photo-SECM is demonstrated.
Voices of Nanomedicine: Blueprint Guidelines for Collaboration in Addressing Global Unmet Medical Needs
Rajendra Prasad *- ,
Arnab Ghosh - ,
Vinay Patel - ,
Berney Peng - ,
Bárbara B. Mendes - ,
Eaint Honey Aung Win - ,
Lucia Gemma Delogu - ,
Joyce Y. Wong - ,
Kristin J. Pischel - ,
Jayesh R. Bellare - ,
Amnon Bar-Shir - ,
Avnesh S. Thakor - ,
Wolfgang J. Parak - ,
Zaver M. Bhujwalla - ,
Yu Shrike Zhang - ,
Nagavendra Kommineni - ,
Vince M. Rotello - ,
Weibo Cai - ,
Twan Lammers - ,
Teri W. Odom - ,
Govindarajan Padmanaban - ,
Dan Peer - ,
Jonathan F. Lovell - ,
Rohit Srivastava *- ,
Robert Langer - , and
João Conde *
The “Voices” under this Perspective underline the importance of interdisciplinary collaboration and partnerships across several disciplines, such as medical science and technology, medicine, bioengineering, and computational approaches, in bridging the gap between research, manufacturing, and clinical applications. Effective communication is key to bridging team gaps, enhancing trust, and resolving conflicts, thereby fostering teamwork and individual growth toward shared goals. Drawing from the success of the COVID-19 vaccine development, we advocate the application of similar collaborative models in other complex health areas such as nanomedicine and biomedical engineering. The role of digital technology and big data in healthcare innovation is highlighted along with the necessity for specialized education in collaborative practices. This approach is decisive in advancing healthcare solutions, leading to improved treatment and patient outcomes.
Role of Competing Magnetic Exchange on Non-Collinear to Collinear Magnetic Ordering and Skyrmion Stabilization in Centrosymmetric Hexagonal Magnets
Dola Chakrabartty - ,
Mihir Sahoo - ,
Amit Kumar - ,
Sk Jamaluddin - ,
Bimalesh Giri - ,
Hitesh Chhabra - ,
Kalpataru Pradhan *- , and
Ajaya K. Nayak *
Topological magnetic skyrmions with helicity state degrees of freedom in centrosymmetric magnets possess great potential for advanced spintronics applications and quantum computing. Till date, the skyrmion study in this class of materials mostly remains focused to collinear ferromagnets with uniaxial magnetic anisotropy. Here, we present a combined theoretical and experimental study on the competing magnetic exchange-induced evolution of noncollinear magnetic ground states and its impact on the skyrmion formation in a series of centrosymmetric hexagonal noncollinear magnets, MnFe1–xCoxGe. We show that by engineering the Fe/Co ratio, the system progressively transforms from a noncollinear magnetic state with in-plane antiferromagnetic ordering in MnFeGe to a collinear ferromagnetic (FM) spin arrangement in MnFe0.2Co0.8Ge. We utilize Lorentz transmission electron microscopy, neutron diffraction experiments, and micromagnetic simulations to demonstrate the role of competing magnetic exchange-induced in-plane magnetic moment in the formation of nontopological type-II magnetic bubbles in the system. However, skyrmions with degenerate helicity states are found to be stable magnetic entities in the case of the perfect uniaxial magnetic anisotropy system. The present study offers a great opportunity to tune the skyrmion phase in centrosymmetric magnets by intrinsically designing the magnetic ground state, thereby providing a unique platform for realizing skyrmion-based spintronics devices.
Resolving Artifacts and Improving the Detection Limit in Circular Differential Scattering Measurement of Chiral and Achiral Gold Nanorods
Hao Li - ,
Kyle Van Gordon - ,
Heng Zhang - ,
Le Wang - ,
Ningneng Hu - ,
Luis M. Liz-Marzán *- , and
Weihai Ni *
Circular differential scattering (CDS) spectroscopy has been developed as a powerful method for the characterization of the optical activity of individual plasmonic nanostructures and their complexes with chiral molecules. However, standard measurement setups often result in artifacts that have long raised concerns on the interpretation of spectral data. In fact, the detection limit of CDS setups is constrained by the high level of artifacts, to ±10%. We address this issue by means of a detailed theoretical description of changes in the polarization state when circularly polarized light is reflected at a dark-field condenser. As a result, we propose a modified CDS configuration based on sequentially placing the quarter-wave plate and linear polarizer within the detection optical path, to analyze the circular polarization state of the light scattered by individual particles. Extensive analysis demonstrates a detection limit of ±1.5% for the modified configuration, which is significantly lower than that for the conventional setup. As a standard system for CDS measurements, both achiral and chiral gold nanorods (AuNRs) were characterized using both setups. With achiral AuNRs, linear dichroism (LD) artifacts in the conventional setup are found to originate from LD present in the excitation light and are only present if anisotropic excitation is produced as a result of the misalignment of the excitation light to the condenser. With chiral AuNRs, CDS spectra recorded with the conventional setup depend on the orientation of the chiral AuNRs with respect to the x-axis of the microscope and are reversed compared to those on the colloid and measured in the modified configuration. The results are in good agreement with theoretical simulations for both configurations.
Digital Profiling of Tumor Extracellular Vesicle-Associated RNAs Directly from Unprocessed Blood Plasma
Elizabeth Maria Clarissa - ,
Sumit Kumar *- ,
Juhee Park - ,
Mamata Karmacharya - ,
In-Jae Oh *- ,
Mi-Hyun Kim - ,
Jeong-Seon Ryu - , and
Yoon-Kyoung Cho *
Tumor-derived extracellular vesicle (tEV)-associated RNAs hold promise as diagnostic biomarkers, but their clinical use is hindered by the rarity of tEVs among nontumor EVs. Here, we present EV-CLIP, a highly sensitive droplet-based digital method for profiling EV RNA. EV-CLIP utilizes the fusion of EVs with charged liposomes (CLIPs) in a microfluidic chip. Optimized CLIP surface charge enables exceptional sensitivity and selectivity for EV-derived miRNAs and mRNAs. This approach streamlines detection with minimal plasma volume (20 μL) and eliminates the need for prior EV isolation or RNA preparation, preventing loss of EVs or RNA. In testing with 83 patient samples, EV-CLIP detected EGFR L858R and T790M mutations with high AUC values of 1.0000 and 0.9784, respectively. Its success in serial monitoring during chemotherapy highlights its potential for precise quantification of rare EV subpopulations, facilitating the exploration of single EV RNA content and enhancing understanding of diverse EV populations in various disease states.
Highly Efficient Blue Light-Emitting Diodes Enabled by Gradient Core/Shell-Structured Perovskite Quantum Dots
Bo Xu *- ,
Shichen Yuan - ,
Linqin Wang - ,
Xiansheng Li - ,
Zhuang Hu - , and
Haibo Zeng *
Room temperature (RT) synthesized mixed bromine and chlorine CsPbBrxCl3–x perovskite quantum dots (Pe-QDs) offer notable advantages for blue quantum dot light-emitting diodes (QLEDs), such as cost-effective processing and narrow luminescence peaks. However, the efficiency of blue QLEDs using these RT-synthesized QDs has been limited by inferior crystallinity and deep defect presence. In this study, we demonstrate a precise approach to constructing high-quality gradient core–shell (CS) structures of CsPbBrxCl3–x QD through anion exchange. Characterization shows that these CS-QDs exhibit a type-I band alignment with a high bromine concentration in the core and a high chlorine concentration in the shell. This unique configuration results in a larger exciton binding energy and reduced defect density, leading to enhanced exciton radiative recombination. Consequently, QLEDs using CS-QDs achieve an external quantum efficiency (EQE) of 16.28%, a maximum luminance of 8423.35 cd/m2, and improved operational stability, surpassing the 12.80% EQE of reference QLEDs made with homogeneous structured QDs (HS-QDs). These findings present a strategy for developing high-quality RT-synthesized blue CS-QDs, marking a significant advancement in the field of efficient pure-blue QLEDs.
Substructure-Specific Antibodies Against Fentanyl Derivatives
Asheley Chapman - ,
Minghao Xu - ,
Michelle Schroeder - ,
Jason M. Goldstein - ,
Asiya Chida - ,
Joo R. Lee - ,
Xiaoling Tang - ,
Rebekah E. Wharton *- , and
M. G. Finn *
This publication is Open Access under the license indicated. Learn More
Structural variants of the synthetic opioid fentanyl are a major threat to public health. Following an investigation showing that many derivatives are poorly detected by commercial lateral flow and related assays, we created hapten conjugate vaccines using an immunogenic virus-like particle carrier and eight synthetic fentanyl derivatives designed to mimic the structural features of several of the more dangerous analogues. Immunization of mice elicited strong antihapten humoral responses, allowing the screening of hundreds of hapten-specific hybridomas for binding strength and specificity. A panel of 13 monoclonal IgG antibodies were selected, each showing a different pattern of recognition of fentanyl structural variations, and all proving to be highly efficient at capturing parent fentanyl compounds in competition ELISA experiments. These results provide antibody reagents for assay development as well as a demonstration of the power of the immune system to create binding agents capable of both broad and specific recognition of small-molecule targets.
On-Demand Selection of the Latent Domain Orientation in Spray-Deposited Block Copolymer Thin Films
Semih Cetindag - ,
Beatrice Bellini - ,
Ruipeng Li - ,
Esther H.R. Tsai - ,
Dmytro Nykypanchuk - , and
Gregory S. Doerk *
With their ability to self-assemble spontaneously into well-defined nanoscale morphologies, block copolymer (BCP) thin films are a versatile platform to fabricate functional nanomaterials. An important challenge to wider deployment of BCPs in nanofabrication is combining precise control over the nanoscale domain orientation in BCP assemblies with scalable deposition techniques that are applicable to large-area, curved, and flexible substrates. Here, we show that spray-deposited smooth films of a nominally disordered BCP exhibit latent orientations, which can be prescriptively selected by controlling solvent evaporation during spray casting. Subsequent solvent vapor annealing triggers assembly toward highly ordered cylindrical morphologies along the pathway determined by solvent evaporation in the prior spray deposition stage. Faster evaporation promotes assembly of vertically oriented cylinders spanning the entire film thickness (100–300 nm). In comparison, slow solvent evaporation permits intermicellar aggregation and incipient cylinder formation in solution, which induces horizontal cylinder assembly upon annealing. The evaporatively controlled latent orientation mechanism presented herein elucidates how nonequilibrium phenomena during casting govern successive self-assembly pathways and facilitates a versatile method to dictate the domain orientation of BCP thin films on demand on flexible and highly curved substrates or in distinct pattern areas on the same substrate.
On-Surface Synthesis and Characterization of Radical Spins in Kagome Graphene
Rémy Pawlak *- ,
Khalid N. Anindya - ,
Outhmane Chahib - ,
Jung-Ching Liu - ,
Paul Hiret - ,
Laurent Marot - ,
Vincent Luzet - ,
Frank Palmino - ,
Frédéric Chérioux - ,
Alain Rochefort - , and
Ernst Meyer *
This publication is Open Access under the license indicated. Learn More
Flat bands in Kagome graphene might host strong electron correlations and frustrated magnetism upon electronic doping. However, the porous nature of Kagome graphene opens a semiconducting gap due to quantum confinement, preventing its fine-tuning by electrostatic gates. Here we induce zero-energy states into a semiconducting Kagome graphene by inserting π-radicals at selected locations. We utilize the on-surface reaction of tribromotrioxoazatriangulene molecules to synthesize carbonyl-functionalized Kagome graphene on Au(111), thereafter modified in situ by exposure to atomic hydrogen. Atomic force microscopy and tunneling spectroscopy unveil the stepwise chemical transformation of the carbonyl groups into radicals, which creates local magnetic defects of spin state S = 1/2 and zero-energy states as confirmed by density functional theory. The ability to imprint local magnetic moments opens up prospects to study the interplay between topology, magnetism, and electron correlation in Kagome graphene.
January 8, 2025
AI-Based Prediction of Protein Corona Composition on DNA Nanostructures
Jared Huzar - ,
Roxana Coreas - ,
Markita P. Landry - , and
Grigory Tikhomirov *
This publication is Open Access under the license indicated. Learn More
DNA nanotechnology has emerged as a powerful approach to engineering biophysical tools, therapeutics, and diagnostics because it enables the construction of designer nanoscale structures with high programmability. Based on DNA base pairing rules, nanostructure size, shape, surface functionality, and structural reconfiguration can be programmed with a degree of spatial, temporal, and energetic precision that is difficult to achieve with other methods. However, the properties and structure of DNA constructs are greatly altered in vivo due to spontaneous protein adsorption from biofluids. These adsorbed proteins, referred to as the protein corona, remain challenging to control or predict, and subsequently, their functionality and fate in vivo are difficult to engineer. To address these challenges, we prepared a library of diverse DNA nanostructures and investigated the relationship between their design features and the composition of their protein corona. We identified protein characteristics important for their adsorption to DNA nanostructures and developed a machine-learning model that predicts which proteins will be enriched on a DNA nanostructure based on the DNA structures’ design features and protein properties. Our work will help to understand and program the function of DNA nanostructures in vivo for biophysical and biomedical applications.
January 6, 2025
Lab-on-the-Needles: A Microneedle Patch-Based Mobile Unit for Highly Sensitive Ex Vivo and In Vivo Detection of Protein Biomarkers
Ying-Pei Hsu - ,
Nan-Si Li - ,
Hao-Han Pang - ,
Yu-Chi Pan - ,
Hung-Pei Tsai - ,
Hsiao-Chien Chen - ,
Ying-Tzu Chen - ,
Chen-Hsun Weng - ,
Shiao-Wei Kuo *- , and
Hung-Wei Yang *
This publication is Open Access under the license indicated. Learn More
Detection of biomarkers associated with physiological conditions provides critical insights into healthcare and disease management. However, challenges in sampling and analysis complicate the detection and quantification of protein biomarkers within the epidermal layer of the skin and in viscous liquid biopsy samples. Here, we present the “Lab-on-the-Needles” concept, utilizing a microneedle patch-based sensing box (MNP-based SenBox) for mobile healthcare applications. This system facilitates the rapid capture of protein biomarkers directly from the in situ epidermal layer of skin or liquid biopsies, followed by on-needle analysis for immediate assessment. The integration of horseradish peroxidase-incorporated zeolitic imidazolate framework-8 (HRP@ZIF-8) as a sensitive and stable signal probe, the detection limit for anti-SARS-CoV-2 NP IgA antibodies and various SARS-CoV-2 S1P mutant strains improves by at least 1,000-fold compared to FDA-approved commercial saliva lateral flow immune rapid tests. Additionally, the MNP-based SenBox demonstrated minimally invasive monitoring and rapid quantification of inflammatory cytokine levels (TNF-α and IL-1β) in rats within 30 min using a portable ColorReader. This study highlights the potential of the MNP-based SenBox for the minimally invasive collection and analysis of protein biomarkers directly from in situ epidermal layers of skin or liquid biopsies that might facilitate mobile healthcare diagnostics and longitudinal monitoring.
Solar-Driven Nanofluidic Ion Regulation for Fractional Salt Crystallization and Reutilization
Wei Zhang - ,
Qinghua Ji *- ,
Huaijia Xin - ,
Gong Zhang - ,
Xiaoyang Duan - ,
Shiyuan Deng - ,
Chengzhi Hu - ,
Huijuan Liu - , and
Jiuhui Qu *
Solar water evaporation (SWE) has emerged as an appealing method for water and salt recovery from hypersaline wastewater. However, different ions usually transfer and accumulate uncontrollably during ion–water separation, making salt fractionalization impractical for conventional SWE, and the resulting mixed salts are hard to use and still require significant costs for disposal. To achieve salt fractionalization and reutilization, achieving ion–water and ion–ion separation simultaneously are crucial in advancing SWE toward sustainability. Here, we present a wood-derived nanofluidic solar-driven fractional crystallizer that regulates the ion transfer processes and extracts nearly pure salt from a mixture of salts. SWE continuously induces capillary flow to propel and concentrate the ions in the wood channels. Meanwhile, engineered functional groups on the channel walls dominate the ion separation process via differentiated interactions with different ions. During ion transfer through channels, SO42– approaches the channel wall to compete for the positive charges and propels Cl– away, slowing SO42– transport and enlarging the transport energy barrier gap (2.65 to 19.28 kJ mol–1) between SO42– and Cl–. Through in situ observation, positive charges on the channel wall make SO42– lag Cl– 12.4 times that of bare Wood-D, accounting for the enhanced ion separation and the consequent fractional salt crystallization.
January 3, 2025
Heteropolyacid Ligands in Two-Dimensional Channels Enable Lithium Separation from Monovalent Cations
Xinyao Dong - ,
Xinyu Ai - ,
Weijun He - ,
Yeming Zhai - ,
Ruixiang Guo - ,
Yi-Wei Li - ,
Zhu-Qing Ma - ,
Yang Yang *- , and
Kai-Ge Zhou *
Extracting lithium from salt lakes requires ion-selective membranes with customizable nanochannels. However, it remains a major challenge to separate alkali cations due to their same valences and similar ionic radius. Inspired by the K+ channel of KcsA K+, significant progress has been made in adjusting nanochannel size to control the ion selectivity dominated by alkali cations dehydration. Besides, several works involved incorporating ligands, such as crown ether, into nanochannels based on coordination chemistry to try to promote alkali cation selectivity; nevertheless, only the separation between mono-/bivalent cations has been achieved. Herein, a series of heteropolyacid (HPA) ligands are designed to functionalize two-dimensional (2D) nanochannels, achieving superior lithium perm-selectivity over other alkali cations (16 for Li+/K+), with the Li+ permeation rate increased to four times that of the pristine 2D membrane. We discover that the switching of an ion between its hydration and ion-HPA coordination states elucidates ion-selective transport, and the relatively lower depth of energy well for the exchange from Li+ hydration to Li+-HPA coordination results in the separation of Li+ from other alkali cations. This work demonstrates a principle for exploring novel ligands to develop alkali cation-selective membranes, expanding the potential applications of ion separation membranes in lithium extraction from aquatic sources.
Terahertz Wave Desensitizes Ferroptosis by Inhibiting the Binding of Ferric Ions to the Transferrin
Xiangji Li - ,
Yangmei Li - ,
Junxuan Xu - ,
Xinlian Lu - ,
Shixiang Ma - ,
Lan Sun *- ,
Chao Chang *- ,
Li Min *- , and
Chunhai Fan
Ferroptosis is a classic type of programmed cell death characterized by iron dependence, which is closely associated with many diseases such as cancer, intestinal ischemic diseases, and nervous system diseases. Transferrin (Tf) is responsible for ferric-ion delivery owing to its natural Fe3+ binding ability and plays a crucial role in ferroptosis. However, Tf is not considered as a classic druggable target for ferroptosis-associated diseases since systemic perturbation of Tf would dramatically disrupt blood iron homeostasis. Here, we reported a nonpharmaceutical, noninvasive, and Tf-targeted electromagnetic intervention technique capable of desensitizing ferroptosis with directivity. First, we revealed that the THz radiation had the ability to significantly decrease binding affinity between the Fe3+ and Tf via molecular dynamics simulations, and the modulation was strongly wavelength-dependent. This result provides theoretical feasibility for the THz modulation-based ferroptosis intervention. Subsequent extracellular and cellular chromogenic activity assays indicated that the THz field at 8.7 μm (i.e., 34.5 THz) inhibited the most Fe3+ bound to the Tf, and the wavelength was in good agreement with the simulated one. Then, functional assays demonstrated that levels of intracellular Fe2+, lipid peroxidation, malondialdehyde (MDA) and cell death were all significantly reduced in cells treated with this 34.5 THz wave. Furthermore, the iron deposition, lipid peroxidation, and MDA in the ferroptosis disease model induced by ischemia-reperfusion injury could be nearly eliminated by the same radiation, validating THz wave-induced desensitization of ferroptosis in vivo. Together, this work provides a preclinical exemplar for electromagnetic irradiation-stimulated desensitization of ferroptosis and predicts an innovative, THz wave-based therapeutic method for ferroptosis-associated diseases in the future.
January 2, 2025
Reconfigurable Sequential-Logic-in-Memory Implementation Utilizing Ferroelectric Field-Effect Transistors
Jingjie Niu - ,
Donggyu Kim - ,
Jie Li - ,
Jiahui Lyu - ,
Yoonmyung Lee *- , and
Sungjoo Lee *
This publication is Open Access under the license indicated. Learn More
In modern digital systems, sequential logic circuits store and process information over time, whereas combinational logic circuits process only the current inputs. Conventional sequential systems, however, are complex and energy-inefficient due to the separation of volatile and nonvolatile memory components. This study proposes a compact, nonvolatile, and reconfigurable van der Waals (vdW) ferroelectric field-effect transistor (FeFET)-based sequential logic-in-memory (S-LiM) unit that performs sequential logic operations in two nonvolatile states. Unlike conventional edge computing systems that require separate combinational logic circuits, sequential logic circuits (such as latches for short-term data storage), and nonvolatile memory for long-term data storage, this innovative S-LiM unit integrates logic and memory into a single nonvolatile vdW FeFET device. The nonvolatile ferroelectric elements directly replace both sequential logic and memory in conventional systems, eliminating frequent data transfers, reducing static power, and increasing the storage density. Six distinct logic operations are implemented in a single vdW FeFET through voltage-controlled ferroelectric polarization, highlighting the unit’s reconfigurability. The device shows significant potential for low-power edge computing, especially where frequent power cycling is necessary. Its nonvolatile polarization retains the state without the need for storing processes, enabling rapid recovery at startup, even after extended power-off periods of tens of minutes. These features make the vdW FeFET-based S-LiM unit ideal for energy-efficient, high-density, and low-power edge computing, especially in remote operations with unstable power supplies. This innovation contributes to the development of next-generation, low-power electronics with enhanced efficiency and storage density.
December 31, 2024
Multispectral Integrated Black Arsenene Phototransistors for High-Resolution Imaging and Enhanced Secure Communication
Li Han - ,
Shi Zhang - ,
Shijian Tian - ,
Libo Zhang *- ,
Yingdong Wei - ,
Kaixuan Zhang - ,
Mengjie Jiang - ,
Yuan He - ,
Changlong Liu - ,
Weiwei Tang - ,
Jiale He - ,
Haibo Shu *- ,
Antonio Politano *- ,
Xiaoshuang Chen - , and
Lin Wang *
The demand for broadband, room-temperature infrared, and terahertz (THz) detectors is rapidly increasing owing to crucial applications in telecommunications, security screening, nondestructive testing, and medical diagnostics. Current photodetectors face significant challenges, including high intrinsic dark currents and the necessity for cryogenic cooling, which limit their effectiveness in detecting low-energy photons. Here, we introduce a high-performance ultrabroadband photodetector operating at room temperature based on two-dimensional black arsenene (b-As) nanosheets. This device demonstrates responsivity across visible, near-infrared, and THz spectral ranges, with responsivities reaching 91.6 A/W at 520 nm, 6.3 A/W at 1550 nm, and 7.8 V/W at 0.27 THz. The exceptional THz responsivity is attributed to the use of plasma-wave rectification in antenna-integrated field-effect transistors with asymmetric antennas, enhancing light-matter interaction and facilitating nonlinear rectification within the two-dimensional electron gas of the transistor channel, achieving a voltage-dependent bipolar response. These advanced b-As-based photodetectors also enable secure THz communication through complex logic operations, achieving robust data encryption and high-performance signal processing.
December 26, 2024
Understanding the Formation Dynamics and Physical Properties of Nanocapsules Using Charge Detection Mass Spectrometry
Conner C. Harper - ,
Tracy H. Schloemer - ,
Jacob S. Jordan - ,
Nicole Heflin - ,
Pournima Narayanan - ,
Qi Zhou - ,
Daniel N. Congreve *- , and
Evan R. Williams *
Characterizing the size, structure, and composition of nanoparticles is vital in predicting and understanding their macroscopic properties. In this work, charge detection mass spectrometry (CDMS) was used to analyze nanocapsules (∼10–200 MDa) consisting of a liquid oleic acid core surrounded by a dense silica outer shell. CDMS is an emerging method for nanoparticle analysis that can rapidly measure the mass and charge of thousands of individual nanoparticles. We find that increasing the feed volume of the tetraethylorthosilicate (TEOS) precursor added to form the silica shell of the nanocapsules yielded both higher and broader nanocapsule mass distributions with differentiable densities. A two-dimensional mass versus charge analysis also revealed the formation of two distinct populations of nanocapsules. These two nanocapsule morphologies were also present in transmission electron microscopy (TEM) images and exhibited low-density spherical cores and crescent-shaped cores where the remainder of the core volume was “filled in” by more dense silica. Nanocapsule shell growth kinetics over a ∼48-h synthesis period were also monitored by sampling the reaction mixture at various times, quenching the sampled aliquots, and then characterizing these time-resolved samples by CDMS. The CDMS data reveal three distinct growth phases in nanocapsule formation; rapid initial nucleation, an “inverted” distribution of silica growth, and a final slow growth phase where the rate of mass increase and final nanocapsule masses are dictated by the initial TEOS feed volumes. CDMS-enabled understanding of the diverse nanocapsule sizes, morphologies, and growth dynamics will allow us to better predict nanocapsule properties while reducing the experimental burden in optimizing nanocapsules for real-world applications.