The self-powered cathodic photoelectrochemical (PEC) sensor has attracted widespread attention in recent years due to its excellent anti-interference performance, but its weak sensitivity has limited further application. Herein, a dual-photoelectrode self-powered sensing platform was constructed for high-sensitive detection of oxytetracycline (OTC). To amplify the response signal for the sensor, a two-step approach has been tailored: (i) The self-powered potential was significantly elevated by introducing the CoTiO₃/g-C₃N₄ photoanode to form the dual-photoelectrode system. (ii) Photoelectrode materials were further designed as Z-scheme heterojunctions to prolong the electron lifetime. Compared with the individual g-C₃N₄ semiconductor, the maximum self-powered potential and the average electron lifetime for the Z-scheme heterojunction-based sensing platform enhanced 2.13 times and 2.01 times, respectively, thus significantly amplifying the photocurrent signal. To achieve the selective detection of OTC, a molecularly imprinted polymer film was anchored on the photocathode. The prepared self-powered PEC sensor exhibited good sensitivity, with a detection limit of 0.08 pM. The elevating potential strategy and prolonging electron lifetime offer a new method to amplify the signal for sensitive PEC detection.

中文翻译：

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基于提升电位策略和延长电子寿命的信号放大自供电阴极光电化学传感器


自供电阴极光电化学 （PEC） 传感器因其优异的抗干扰性能近年来引起了广泛关注，但其较弱的灵敏度限制了其进一步的应用。在此，构建了用于土霉素 （OTC） 的高灵敏度检测的双光电电极自供电传感平台。为了放大传感器的响应信号，我们定制了一种两步方法：（i） 通过引入 CoTiO₃/g-C₃N₄ 光阳极形成双光电电极系统，显著提高了自供电电位。（ii） 光电极材料进一步设计为 Z 型异质结以延长电子寿命。与单个 g-C₃N₄ 半导体相比，基于 Z 方案异质结的传感平台的最大自供电电位和平均电子寿命分别提高了 2.13 倍和 2.01 倍，从而显着放大了光电流信号。为了实现 OTC 的选择性检测，在光阴极面上锚定了分子印迹聚合物薄膜。制备的自供电 PEC 传感器表现出良好的灵敏度，检出限为 0.08 pM。提高电位策略和延长电子寿命提供了一种扩增信号的新方法，用于灵敏的 PEC 检测。