(120a) Rapid Pathogen Detection with Integrated Ac Electrokinetic Devices

Rapid and accurate pathogen (bacteria and virus) detection and DNA identification from very dilute samples are the goals of miniature medical diagnostic kits. AC electrokinetic devices for concentrating, transporting and sorting particles may soon achieve such goals because of the various advantages they offer: portability, selectivity and sensitivity. The driving electrodes for these devices do not generate bubbles, thus allowing them to be embedded in the microchannels of the kit to achieve the above performance measures. We review an array of such AC electrokinetic technologies from our laboratory. These include a rapid serum/blood cell separator, a fluorescent nanowire dielectrophoretic transporter and trap, a micro-vortex concentrator for Raman detection of bacteria, micro- and nano- impedance sensors for bacteria and DNA probes ,antibody functionalized dielectrophoretic traps, a chip scale capillary electro-chromatograph and a chip-mass spect interface. These AC electrokinetic devices have been integrated into several kits for various specific detection and identification tasks--an antibiotic susceptibility kit, a sepsis fungi detection kit, a malarial diagnostic kit etc . Depending on the sample matrix and the concentration of the target pathogen, the detection time ranges from one minute to several hours--all significantly shorter than culturing, and with equally large increase in sensitivity.