COLL 2 |
| A compact and low-power microcantilever-based sensor array has been developed and used to detect multiple biological signatures associated with the presence of pathogens in complex media. This device is based on the static deflection of a microfabricated cantilever induced by surface stress changes associated with biological binding. Deflection is measured through the change in resistance of an embedded piezoresistor. The simple electrical measurement enables the compact size and low-power consumption of the sensor. The current device consists of an array of four piezoresistive cantilevers that are each passivated by an encapsulating silicon nitride layer. A thin layer of gold is added to one side to aid biofunctionalization. A microarray spotting pin is used to reliably functionalize one side of each lever individually with thiolated DNA oligonucleotides as well as thiolated antibodies that specifically bind antigens presented on the pathogen surface. A control lever permits common-mode rejection of noise attributed to thermal drift and nonspecific binding of biomolecules. By detecting multiple signatures, selectivity is improved which allows detection of pathogens in complex media. The small size and low power requirements of this device make it valuable as a portable field sensor or in point of care medical diagnostic applications. |
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Nanoscience and Nanotechnology for Chemical and Biological Defense
9:00 AM-12:00 PM, Sunday, August 19, 2007 BCEC -- 151B, Oral
Division of Colloid & Surface Chemistry |