Cathodic photoelectrochemical (PEC) bioassay is more resistant to reductive interferents, and development of high-performance photocathode is imperatively required in precise monitoring target in complex matrices. In this work, a plasmonic Au activated amorphous MoS_x photocathode (a-MoS_x/Au) was fabricated by sequential electrodeposition. Coupled with a sensitization amplification strategy induced by target-aptamer recognition, an ultrasensitive and high-affinitive signal-on cathodic PEC aptasensor for insulin detection was developed. Under optimum conditions, the sensor exhibits a wide linear range (0.1 pg/mL~100 ng/mL) and an ultralow detection limit (28 fg/mL) even lower than most sensors reported so far. Plasmonic Au activation and target-induced sensitization effect are responsible for high-performance PEC aptasensing of insulin at a-MoS_x photocathode.

阴极光电化学（PEC）生物测定法对还原性干扰物的耐受性更高，在复杂基质中的精确监测目标中，迫切需要开发高性能的光阴极。在这项工作中，等离子Au活化的非晶MoS _x光电阴极（a-MoS _x/ Au）是通过顺序电沉积制造的。结合靶标适体识别诱导的敏化扩增策略，开发了一种用于胰岛素检测的超灵敏，高亲和力的阳离子PEC适体传感器。在最佳条件下，该传感器具有较宽的线性范围（0.1 pg / mL〜100 ng / mL）和超低检测限（28 fg / mL），甚至低于迄今为止报道的大多数传感器。等离子体金激活和靶诱导的敏化作用是a-MoS _x阴极对胰岛素的高性能PEC适应性的原因。