Target-Induced Chemical Reaction Modulated Optical Fiber-Gated Organic Photoelectrochemical Transistor for <i>in Vivo</i> H<sub>2</sub>S Detection
Yulan Zeng, Xinyang Wang, Zhonghui Chen, Fang Luo, Bin Qiu, FengFu Fu, Jian Wang, Zhenyu Lin
Abstract
Real time detection of hydrogen sulfide (H 2 S) in deep brain regions is of great significance. Photoelectrochemical (PEC) biosensors hold promise for real-time monitoring but low sensitivity due to the use of small electrode restrained its application. In this study, a miniaturized sensor that integrates organic photoelectrochemical transistors (OPECTs) with optical fiber (OF) microelectrodes was designed for the first time, which can amplify the small PEC signal into large channel current change. A conductive gold layer and cuprous oxide nanoparticles (Cu 2 O NPs) were sequentially deposited onto the OF, followed by a Nafion polymer coating to enhance anti-interference capabilities. Cu 2 O reacts with H 2 S to generate Cu 2 S. The resulting Cu 2 O/Cu 2 S heterojunction induces changes in the PEC signal and channel current. Compared to a conventional PEC system, the OPECT sensor has higher sensitivity and lower detection limit, enabling monitoring of H 2 S concentration fluctuations within the rat brain, which demonstrates the approach’s capability for highly sensitive in vivo biomarker detection.