A Performance Comparison Between Organic Electrochemical Transistor and Electrode Configurations for Enzymatic Sensing

Organic electrochemical transistors (OECTs) excel at biosensing due to their high amplification factor, which allows for detecting low analyte concentrations and picking up weak physiological signals. One prominent use of OECT is in enzymatic metabolite sensing, with the OECT claimed to have a superior low limit of detection and enhanced sensitivity compared to conventional two or three electrode-based setups. However, there has yet to be a direct comparative study on the performance metrics of these sensor configurations under unified conditions. Here, the glucose sensing performance of an enzyme-immobilized electrode is systematically examined in two types of devices that have the same geometrical relations: the first one is a traditional 2- or 3-electrode configuration where the sensing electrode is the working electrode, and in the second one, the enzymatic electrode serves as the gate electrode of an OECT. While benchmarking the performance of OECT technology for enzyme-based metabolite sensing, this study provides insights into the operation mechanism of OECT-based enzymatic sensors. These results can help to design more efficient OECT-based circuits to transduce biological events that involve redox reactions.