Hybridization Chain Reaction-Enhanced Biocatalytic Precipitation on Flower-like Bi₂S₃: Toward Organic Photoelectrochemical Transistor Aptasensing with High Transconductance

Organicphotoelectrochemical transistor (OPECT) bioanalysishasrecently emerged as a promising avenue for biomolecular sensing, providinginsight into the next-generation of photoelectrochemical biosensingand organic bioelectronics. Herein, this work validates the directenzymatic biocatalytic precipitation (BCP) modulation on a flower-likeBi(2)S(3) photosensitive gate for high-efficacyOPECT operation with high transconductance (g (m)), which is exemplified by a prostate-specific antigen (PSA)-dependenthybridization chain reaction (HCR) and subsequent alkaline phosphatase(ALP)-enabled BCP reaction toward PSA aptasensing. It has been shownthat light illumination could ideally achieve the maximized g (m) at zero gate bias, and BCP could efficientlymodulate the device's interfacial capacitance and charge-transferresistance, resulting in a significantly changed channel current (I (DS)). The as-developed OPECT aptasensor realizesgood analysis performance for PSA with a detection limit of 10 fgmL(-1). This work features direct BCP modulation oforganic transistors and is expected to stimulate further interestin exploring advanced BCP-interfaced bioelectronics with unknown possibilities.