Photoactive gate material-based organic photoelectrochemical transistor sensors: working principle and representative applications

Organic photoelectrochemical transistor (OPECT)-based sensors that use light-sensitive semiconductor materials as the gate have recently garnered increasing interest in various fields ranging from biological analysis to environmental monitoring. However, so far, the working principle and representative applications of OPECT sensors have not been discussed and reviewed systematically. In this review, we aim to present a comprehensive overview of the working principle and sensing mechanisms of OPECT-based sensors and various inorganic and organic photoactive gate materials used in OPECTs, with a focus on the representative applications and recent progress of these sensors in the fields of enzyme sensing, immunoassays, and nucleic acid-based sensing. Moreover, the challenges and outlooks that need to be addressed for future advancements in this field are summarized and discussed. This review will assist researchers in gaining a more comprehensive understanding and cognition of new OPECT-based sensing methods and devices.