In2S3‐Gated Organic Photoelectrochemical Transistor with a Stable Transconductance

Abstract Transconductance (gm) is one important figure of merit for benchmarking organic electrochemical transistor (OECT) biosensors, which nevertheless experiences undesired fluctuation instead of keep constant during the target detection of varied concentrations. Light‐matter interplay is recently shown as a potential way to regulate the OECT characteristics, e.g. maximum gm at zero gate bias is achieved. In this work, the challenge of unstable gm is addressed by using a unique metal‐organic framework (MOF)‐derived hollow tube indium sulfide (m‐In2S3) as the photogate. Interestingly, the light irradiation on m‐In2S3 generate a straight transfer curve, leading to a stable gm that is desirable for biological application. Exemplifying by an aptasening, such a device is then tested for protein quantification with a stable sensitivity during the detection. This work features the feasibility of light‐matter interplay to achieve a stable gm in organic electronics.