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High performance wash-free magnetic bioassays through microfluidically enhanced particle specificity.

TitleHigh performance wash-free magnetic bioassays through microfluidically enhanced particle specificity.
Publication TypeJournal Article
Year of Publication2015
AuthorsBechstein DJB, Lee J-R, Ooi CChun, Gani AW, Kim K, Wilson RJ, Wang SX
JournalSci Rep
Volume5
Pagination11693
Date Published2015
ISSN2045-2322
Abstract

Magnetic biosensors have emerged as a sensitive and versatile platform for high performance medical diagnostics. These magnetic biosensors require well-tailored magnetic particles as detection probes, which need to give rise to a large and specific biological signal while showing very low nonspecific binding. This is especially important in wash-free bioassay protocols, which do not require removal of particles before measurement, often a necessity in point of care diagnostics. Here we show that magnetic interactions between magnetic particles and magnetized sensors dramatically impact particle transport and magnetic adhesion to the sensor surfaces. We investigate the dynamics of magnetic particles' biomolecular binding and magnetic adhesion to the sensor surface using microfluidic experiments. We elucidate how flow forces can inhibit magnetic adhesion, greatly diminishing or even eliminating nonspecific signals in wash-free magnetic bioassays, and enhancing signal to noise ratios by several orders of magnitude. Our method is useful for selecting and optimizing magnetic particles for a wide range of magnetic sensor platforms.

DOI10.1038/srep11693
Alternate JournalSci Rep
PubMed ID26123868
PubMed Central IDPMC4485157
Grant ListU54CA143907 / CA / NCI NIH HHS / United States
U54CA151459 / CA / NCI NIH HHS / United States