Smartphone based portable bacteria pre-concentrating microfluidic sensor and impedance sensing system

Portable low-cost sensors and sensing systems for the identification and quantitative measurement of bacteria in field water are critical in preventing drinking water from being contaminated by bacteria. In this article, we reported the design, fabrication and testing of a low-cost, miniaturized and sensitive bacteria sensor based on electrical impedance spectroscopy method using a smartphone as the platform. Our design of microfluidics enabled the pre-concentration of the bacteria which lowered the detection limit to 10 bacterial cells per milliliter. We envision that our demonstrated smartphone-based sensing system will realize highly-sensitive and rapid in-field quantification of multiple species of bacteria and pathogens.