Developing new self-powered sensors is highly demanded for smart portable electronic devices. Herein, a novel visible-light-driven self-powdered aptasensor with a metal-ligand charge transfer (MLCT)-induced signal-off strategy was established for microcystin-LR (MC-LR) sensing. The aptasensor was based on a self-breathing-like dual photoelectrode photocatalytic fuel cell (PFC) that was assembled with visible-light responsive ternary NG-TiO₂-Ag and NG-BiOBr nanocomposites as photoelectrodes. The device did not require aeration or a membrane in a single-compartment cell. The self-powdered PFC system exhibited a greater power output than previously-reported ones that used only TiO₂. The photo-triggered self-bias between the photoelectrodes generated electron transfer and a power output in the external circuit. A self-powered aptasensor for MC-LR was constructed using an MC-LR-binding aptamer as the recognition element. The results showed an unexpected sequential decrease in power output, followed by the capture of MC-LR, which is different from earlier signal-on strategies. The inhibited output of the PFC after MC-LR capture was controlled by an MLCT-induced signal-off mechanism, which was confirmed by the UV–Vis absorption and fluorescence emission spectra. Furthermore, the power output of the self-powdered sensor depended on the MC-LR concentration. When used for ultrasensitive trace MC-LR detection, the self-powdered sensor showed a linear relationship from 1 pM to 316 nM and a detection limit of 0.33 pM. This work provides theoretical guidance for sensing strategies using self-powdered sensors and offers a rational device design for cost-effective electricity generation from renewable resources.

对于智能便携式电子设备，迫切需要开发新的自供电传感器。本文中，建立了一种新型的可见光驱动的自粉末适体传感器，该传感器具有金属配体电荷转移（MLCT）诱导的信号关闭策略，用于微囊藻毒素-LR（MC-LR）感测。适体传感器基于类似自呼吸的双光电极光催化燃料电池（PFC），该燃料电池与可见光响应性三元NG-TiO ₂ -Ag和NG-BiOBr纳米复合材料组装为光电极。该设备不需要在单隔室中通气或使用隔膜。与以前报告的仅使用TiO _2的系统相比，自粉末化的PFC系统显示出更大的功率输出。光电极之间的光触发自偏置会在外部电路中产生电子转移和功率输出。使用MC-LR结合适体作为识别元件构建了MC-LR的自供电适体传感器。结果表明，功率输出出现了意外的顺序下降，随后捕获了MC-LR，这与早期的信号接通策略不同。MC-LR捕获后，PFC的抑制输出受MLCT诱导的信号关闭机制控制，这已由UV-Vis吸收和荧光发射光谱证实。此外，自粉末传感器的功率输出取决于MC-LR浓度。当用于超灵敏的痕量MC-LR检测时，自粉状传感器的线性关系为1 pM至316 nM，检测极限为0.33 pM。