Nanotechnology Aids Development of Pathogen Biosensors

Neil H. Mermelstein

November 1, 2011

Materials at the nanoscale level have different properties from those at the micro and macro levels, including chemical, biological, or magnetic properties; altered electrical or optical activity; increased structural integrity; or other unique characteristics. Two research approaches take advantage of these properties in the development of biosensors for detection of foodborne pathogens.

Graduate student Lateef Syed records videos during a dielectrophoretic E. coli capture experiment. A fluid containing fluorescencelabeled bacteria is passed at a fixed velocity through the device, and the dielectrophoretic capture and release of the bacteria can be observed under a fluorescence microscope as a reversible process when the voltage is turned on and off. Electrophoretic Approach
Jun Li, Associate Professor of Chemistry at Kansas State University, is developing a …

Cross-sectional schematic view of the nanodielectrophoretic device used to capture E. coli. It consists of the nanoelectrode array (NEA) on the bottom and an indium tin oxide (ITO) transparentglass macro-electrode on top. The experiments are performed by placing the device under an upright optical microscope with a charge-coupled-device (CCD) video camera on top to record the process.