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Giant Magenetoresistive Sensors. 2. Detection of Biorecognition Events at Self-Referencing and Magnetically Tagged Arrays

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Rachel L. Millen, John Nordling, Heather A. Bullen^† and Marc D. Porter*

Departments of Chemistry and Chemical Engineering, Ames Laboratory

USDOE, and Institute for Combinatorial Discovery, Iowa State University, Ames, Iowa 50011

Mark Tondra^‡

NVE Corporation, Eden Prairie, Minnesota 55433

Michael C. Granger

Department of Chemistry, University of Utah, 383 Colorow Road, Salt Lake City, Utah 84108

Anal. Chem., 2008, 80 (21), pp 7940–7946

DOI: 10.1021/ac800967t

Publication Date (Web): October 1, 2008

* To whom correspondence should be addressed. Present address: Departments of Chemistry, Chemical Engineering, and Bioengineering, University of Utah, 383 Colorow Road, Salt Lake City, UT 84108 (marc.porter@utah.edu)., †

Present address: Department of Chemistry, Northern Kentucky University, Highland Heights, KY 41099.

, ‡

Present address: Diagnostic Biosensors, LLC, 1712 Brook Ave. SE, Minneapolis, MN 55414.

Section:

Biochemical Methods

Abstract

Microfabricated devices formed from alternating layers of magnetic and nonmagnetic materials at combined thicknesses of a few hundred nanometers exhibit a phenomenon known as the giant magnetoresistance effect. Devices based on this effect are known as giant magnetoresistive (GMR) sensors. The resistance of a GMR is dependent on the strength of an external magnetic field, which has resulted in the widespread usage of such platforms in high-speed, high-data density storage drives. The same attributes (i.e., sensitivity, small size, and speed) are also important embodiments of many types of bioanalytical sensors, pointing to an intriguing opportunity via an integration of GMR technology, magnetic labeling strategies, and biorecognition elements (e.g., antibodies). This paper describes the utilization of GMRs for the detection of streptavidin-coated magnetic particles that are selectively captured by biotinylated gold addresses on a 2 × 0.3 cm sample stick. A GMR sensor network reads the addresses on a sample stick in a manner that begins to emulate that of a “card-swipe” system. This study also takes advantage of on-sample magnetic addresses that function as references for internal calibration of the GMR response and as a facile means to account for small variations in the gap between the sample stick and sensor. The magnetic particle surface coverage at the limit of detection was determined to be 2%, which corresponds to 800 binding events over the 200 × 200 μm capture address. These findings, along with the potential use of streptavidin-coated magnetic particles as a universal label for antigen detection in, for example, heterogeneous assays, are discussed.

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This article has been cited by 2 ACS Journal articles (2 most recent appear below).

A Three-Layer Competition-Based Giant Magnetoresistive Assay for Direct Quantification of Endoglin from Human Urine
Balasubramanian Srinivasan, Yuanpeng Li, Ying Jing, Chengguo Xing, Joel Slaton, and Jian-Ping Wang
Analytical Chemistry2011 83 (8), 2996-3002
- A Three-Layer Competition-Based Giant Magnetoresistive Assay for Direct Quantification of Endoglin from Human Urine
  Balasubramanian Srinivasan, Yuanpeng Li, Ying Jing, Chengguo Xing, Joel Slaton, and Jian-Ping Wang
  Analytical Chemistry2011 83 (8), 2996-3002
  This study presents a three-layer competition-based assay for ultrasensitive detection and quantification of endoglin from unprocessed human urine samples using a giant magnetoresistive (GMR) sensor and high-moment magnetic nanoparticle-based biosensing ...
  Abstract | Full Text HTML | Hi-Res PDF | PDF w/ Links
Giant Magnetoresistance Sensors. 1. Internally Calibrated Readout of Scanned Magnetic Arrays
John Nordling, Rachel L. Millen, Heather A. Bullen and Marc D. Porter, Mark Tondra, Michael C. Granger
Analytical Chemistry2008 80 (21), 7930-7939
- Giant Magnetoresistance Sensors. 1. Internally Calibrated Readout of Scanned Magnetic Arrays
  John Nordling, Rachel L. Millen, Heather A. Bullen and Marc D. Porter, Mark Tondra, Michael C. Granger
  Analytical Chemistry2008 80 (21), 7930-7939
  This paper describes efforts aimed at setting the stage for the application of giant magnetoresistance sensor (GMRs) networks as readers for quantification of biolytes selectively captured and then labeled with superparamagnetic particles on a scanned ...
  Abstract | Full Text HTML | Hi-Res PDF | PDF w/ Links