Web Release Date: January 29,
Poly(N-vinyl-2-pyrrolidone) (PVP)-Capped Dendritic Gold Nanoparticles by a One-Step Hydrothermal Route and Their High SERS Effect
and
National Center for Nanoscience and Technology, Beijing 100080, People's Republic of China, Institute for Materials Chemistry and Engineering, Kyushu University, and CREST, Japanese Science and Technology, Kasuga, Fukuoka 816-8580, Japan, and Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100080, People's Republic of China
Received May 19, 2007
In Final Form: December 31, 2007
Abstract:
Dendritic gold (Au) nanoparticles have been successfully synthesized by the one-step hydrothermal reduction of HAuCl4·4H2O using ammonium formate (AF) as a reducing agent in the presence of PVP. Effects of different reactant concentrations on the morphologies of obtained products have been systematically investigated. On the basis of the morphologies of the products observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), it has been found that an excessive number of AF molecules are the origin of the dendritic Au particles besides PVP as a stabilizer. AF molecules serve not only as a reductant but probably also as a capping reagent. The study implies that the use of two or more capping reagents with different adsorption abilities will be beneficial to the formation of hyperbranched Au nanoparticles. The new finding will have the potential to be extended to the construction of other highly branched noble metal nanoparticles only by one-step synthesis. In addition, as an example, application of the dendritic particles as an active material in surface-enhanced Raman scattering has been investigated by employing 4-aminothiophenol molecules as a probe.
Download the full text: PDF | HTML
