A Self-Powered Paper-Based Microbial Sensor for Lactate Monitoring in Sweat

Abstract

We created a self-powered, paper-based lactate biosensor by using microbial electrochemical activities. Electricity-producing bacterial cells were pre-inoculated in an engineered conductive reservoir on paper. Upon adding a drop of sweat, bacterial cells started their metabolism through oxidation of the biodegradable organic substrate, lactate, and transferred produced electrons to the electrode. Because the harvested electrons were based on their electrochemical energy conversion and were proportional to the lactate concentration, the current output can be used as a transducing signal for lactate monitoring in sweat.