Sensitive detection and effective inactivation of bacteria are essential in preventing foodborne bacterial infection that poses a significant threat to human health. Herein, a near-infrared (NIR)-driven multifunctional photoelectrochemical (PEC) biosensor was constructed for detection and inactivation of . Based on the covalent bonding between amine and carboxyl groups, carboxyl-functionalized SA31 aptamer was immobilized on the PDA/MnO photoelectrode. In the presence of , SA31 aptamer can specifically capture , causing the decrease of photocurrent signal owing to steric hindrance effect. Leveraging photocurrent-off signal, there existed a satisfied linear relationship between the photocurrent variation and the logarithm of concentration, achieving a wide linear range from 10 to 10 CFU/mL with a low detection limit of 2.0 CFU/mL. Notably, PDA/MnO with peroxidase-like activity facilitated the catalytic oxidation of with assistance of hydrogen peroxide (HO) to cause the inactivation of . Desorption of inactivated from the photoelectrode led to a recovery of photocurrent signal, enabling a "signal on" switch. Simultaneously, the excellent photothermal performance of the PDA/MnO converted light energy into heat energy under the irradiation of NIR light (808 nm, 1.5 W/cm), triggering the synergistic antibacterial effect against (97.36%). This work provides a novel strategy for fabricating the detection and inactivation of bacteria in practical applications.

中文翻译：

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基于适配体修饰的 PDA/MnO2 光电极的近红外驱动多功能 PEC 生物传感器，用于细菌检测和灭活

细菌的灵敏检测和有效灭活对于预防对人类健康构成重大威胁的食源性细菌感染至关重要。在此，构建了近红外（NIR）驱动的多功能光电化学（PEC）生物传感器，用于检测和灭活。基于胺和羧基之间的共价键合，羧基功能化的SA31适体被固定在PDA/MnO光电极上。当 存在时，SA31 适体可以特异性捕获 ，由于空间位阻效应导致光电流信号减弱。利用光电流关闭信号，光电流变化与浓度对数之间存在令人满意的线性关系，实现了10至10 CFU/mL的宽线性范围和2.0 CFU/mL的低检测限。值得注意的是，具有过氧化物酶样活性的 PDA/MnO 在过氧化氢 (H2O) 的帮助下促进 的催化氧化，从而导致 的失活。失活物质从光电极上解吸导致光电流信号恢复，从而实现“信号开启”开关。同时，PDA/MnO优异的光热性能在近红外光（808 nm，1.5 W/cm）照射下将光能转化为热能，引发协同抗菌作用（97.36%）。这项工作为实际应用中细菌的检测和灭活提供了一种新的策略。