Microfluidic biosensor for single cell high speed flow impedance spectroscopy

This paper presents a micro-biosensor based on Electrical Bio-Impedance Spectroscopy (EBIS), applied to blood cells characterization and diagnosis. This sensor uses microfluidic flow, coupled to EBIS system to perform cell by cell measurements at high flow rate, up to several hundred cells per second. Two devices were realized with different materials, SU_8 resin and polydimethylsyloxane PDMS to structure the microchannel. PDMS device stand higher pressure than SU_8, permitting to improve sensor reliability and the possibility to clean it. Measurements confirm it ability to detect and characterize each cell and particle in less than 1ms during their passage in a microchannel, allowing high speed diagnosis of a large amount of cells. Calibrated particles were used to check the proper functioning of the sensor and the possibility to detect and measure few variation induce by the passage of cells.