Graphene Photoelectrochemical Transistor for Dual‐Directional Signal‐on Biosensing

Abstract Recent research has demonstrated the potential of photogating in regulating the characteristics of photoelectrochemical transistors. Here it is reported graphene photoelectrochemical transistor (GPECT) with dual‐directional signal‐on biosensing as exemplified by graphene channel gated by p/n‐type metal–organic frameworks (MOFs) upon light illumination toward aptasensing. Due to the dual‐directional shift of the Dirac point induced by p/n‐type MOFs, signal‐on operation with mutually verifiable dual readout could be achieved. For aptasensing, with the assistance of biocatalytic precipitation reaction, such a device is validated for highly sensitive detection of thrombin with limits of detection as low as 5.2 and 0.1 fm, respectively. This study demonstrates not only a general protocol of GPECTs but also the potential of unique photogating in GPECTs toward novel optoelectronics.