Organic thin film transistors (OTFTs) have been explored for sensing applications for several decades due to their many advantages like easy fabrication,low cost,flexibility,and biocompatibility.Among these OTFTs,organic electrochemical transistors (OECTs) have attracted a great deal of interest in recent years since the devices can operate stably in aqueous environment with relatively low working voltages (＜1V) and are suitable for applications in chemical and biological sensing.Due to their excellent performances,various chemical and biological sensors have been developed by OECTs,like ion sensors,glucose sensors,DNA sensors,and cell-based biosensors.