A Monolithic Dielectrophoresis Chip With Impedimetric Sensing for Assessment of Pathogen Viability

Here, we report a rapid and low-cost live/dead assay for bacteria in aqueous samples via a dielectrophoresis (DEP) technique employed in a microfluidic platform. The platform has reusable compartment housing the microelectrodes for DEP activation and bioimpedance sensing. The disposable compartment contains the sample inlet and outlet and the microfluidic channel for sample analysis. The chip has an array of insulating pillars for generating DEP forces on bacteria and a focusing region for enhanced impedance signal. The DEP force is utilized to enrich bacteria and selectively release them by tuning the frequency of the applied electric field. An algorithm is implemented to determine the concentration of live bacteria in the mixture by analyzing the magnitude and duration of the measured impedance. The chip performance was validated by analyzing various ratios of live/dead bacteria and was compared with parallel flow cytometry experiments. [2018-0100]