High efficiency E. coli concentration via dynamic light-induced optoelectro-osmosis flow


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We demonstrate a dynamic light-induced optoelectroosmosis flow design for E. coli concentration on an organic photoconductive material based biochip. Several traditional approaches of purification and enrichment for bacteria are to use magnetic beads coated with antibodies to attract them. The efficiency of collecting magnetic beads is equal to sort bacteria. Our work provides a direct method to enrich the E. coli concentration with dynamic light image. Due to the application of photoconductive material, TiOPc, two features are demonstrated, simple biochip fabrication processes and rapid E. coli collection. The biochip is fabricated only with spin-coating a thin TiOPc layer, 500nm, on the indium tin oxide (ITO) conductive glass. Besides, the E. coli are concentrated together within 30 sec toward the illuminating region by the surface charge slip. We also calibrate the dominating effects in different applied ac frequency region. In low frequency, electrolysis would generate bubble to destroy the chip structure. In 1~100 kHz, electroosmosis flow would attract the E. coli toward projected light pattern. Upon 10 kHz~20 MHz, dielectrophoresis forms the E. coli as a 3D columnar structure. In conclusion, our light-induced E. coli manipulation approach would expand the scope of the examination efficiency, for example, water quality.

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Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2011: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational
Published: June 13, 2011
Pages: 512 - 515
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topics: Micro & Bio Fluidics, Lab-on-Chip
ISBN: 978-1-4398-7139-3