Development of a capillary-driven, microfluidic, nucleic acid biosensor

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An ideal point-of-care device would incorporate the simplicity and reliability of a lateral flow assay with a microfluidic device. Our system consists of self-priming microfluidics with sealed conjugate pads of reagent delivery and an absorbent pad for additional fluid draw. Using poly(methyl methacrylate) as a microfluidic substrate, we have developed a single-step surface modification method which allows strong capillary flow within a sealed microchannel. For our biosensor design, we have incorporated aspects of lateral flow assays within our device. Conjugate pads within the device held trapped magnetic nanoparticles which were released when the sample entered the chamber. In addition, nucleic-acid-probe-conjugated horseradish peroxidase was released on a second conjugate pad. The complex consisting of the magnetic nanoparticle, target nucleic acid and HRP was immobilized over a magnet while a co-reactant stream containing H2O2 was merged with the channel. A downstream electrode attached to a potentiostat was able to quantify the signal. This new format of biosensor will allow for a smaller and more portable point-of-care biosensor. The design also allows to commercial-scale manufacturing and low materials cost. The potentiostat can be miniaturized to allow for a truly handheld system which and conduct assays on a disposable chip.

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Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2011: Bio Sensors, Instruments, Medical, Environment and Energy
Published: June 13, 2011
Pages: 32 - 35
Industry sectors: Medical & Biotech | Sensors, MEMS, Electronics
Topicss: Chemical, Physical & Bio-Sensors, Diagnostics & Bioimaging
ISBN: 978-1-4398-7138-6