Detection of bacteria with organic electrochemical transistors

Organic electrochemical transistors (OECTs) are successfully used for the detection of bacteria ( E. coli O157:H7) in KCl electrolytes. The transfer characteristic of the OECT shifts to higher gate voltage after bacteria are captured on the active layer of the device, which can be attributed to the electrostatic interaction between the bacteria and the transistor. The OECT with a Pt gate electrode shows a voltage shift of up to 55 mV after the capture of bacteria. The influence of the ion concentration of the electrolyte on the device performance is also studied. It is expected that the organic transistors will find promising applications as disposable bacteria sensors. Organic electrochemical transistors were modified with antibodies and used to detect bacteria in solution for the first time.