MagArray Biochips for Protein and DNA Detection with Magnetic Nanotags: Design, Experiment, and Signal-to-Noise Ratio
MagArray™ chips contain arrays of magnetic sensors, which can be used to detect surface binding reactions of biological molecules that have been labeled with 10 to 100 nm sized magnetic particles. Although MagArray chips are in some ways similar to fluorescence-based DNA array chips, the use of magnetic labeling tags leads to many distinct advantages, such as better background rejection, no label bleaching, inexpensive chip readers, potentially higher sensitivity, ability to measure multiple binding reactions in homogeneous assays simultaneously and in real-time, and seamless integration with magnetic separation techniques. So far, the technology of MagArray chips has been successfully used to perform quantitative analytic bioassays of both protein and nucleic acid targets. The potential of this technology, especially for point-of-care testing (POCT) and portable molecular diagnostics, appears promising, and it is likely that this technology will see significant further performance gains in the near future.
KeywordsHard Disk Drive Nonspecific Adsorption Spin Valve Differential Pair Free Layer
The authors would like to thank the following collaborators: N. Pourmand and H. Yu for their expertise in biochemistry, S. Sun for expertise in nanoparticle synthesis, and S. Han for electronic instrumentation. Funding was generously provided by the U.S. Department of Defense, the National Institutes of Health, and the Whitaker Foundation for Biomedical Engineering.
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