In₂S₃‐Gated Organic Photoelectrochemical Transistor with a Stable Transconductance

Abstract Transconductance (g_m) 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 g_m at zero gate bias is achieved. In this work, the challenge of unstable g_m 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 g_m 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 g_m in organic electronics.