Using staggered-gap ZnO/BiFeO₃ heterojunction as photoactive materials and cDNA-CdS as the sensitizer for sensitive Kanamycin (KAN) detection, we have created a unique signal-off biosensing platform. The ZnO/BiFeO₃ heterojunction provides active sites for aptamer loading and enhances photocurrent responsiveness. Rapid interfacial charge transfer and the separation efficiency of photo-generated carriers are enhanced by sensitization of the ternary heterojunction ZnO/BiFeO₃/CdS. Signal-amplified quenching occurs when sensitizers are replaced with sterically hindered KAN. Because of the aptamer's greater affinity for KAN, the replacement of CdS causes a decrease in photocurrent response. Additionally, the weakly conductive aptamer-KAN complex causes steric hindrance, which exacerbates the photoelectrochemical signal-damping effect even more. The photoelectrochemical aptasensor exhibits excellent selectivity and stability, detecting KAN within the range of 0.00005825–0.233 μg/mL with a detection limit of 0.0466 ng/mL (S/N = 3). This work demonstrates the potential of perovskite oxides and their heterostructures for advanced photoelectrochemical biosensing applications.

使用交错间隙ZnO/BiFeO ₃异质结作为光敏材料和cDNA-CdS作为灵敏卡那霉素（KAN）检测的敏化剂，我们创建了一个独特的信号关闭生物传感平台。ZnO/BiFeO ₃异质结为适体负载提供了活性位点并增强了光电流响应性。_{三元异质结ZnO/BiFeO 3} /CdS的敏化增强了快速界面电荷转移和光生载流子的分离效率。当敏化剂被位阻 KAN 取代时，会发生信号放大猝灭。由于适配体对 KAN 的亲和力较大，CdS 的替代会导致光电流响应降低。此外，弱导电适体-KAN复合物会引起空间位阻，从而进一步加剧光电化学信号阻尼效应。该光电化学适体传感器表现出优异的选择性和稳定性，检测KAN的范围为0.00005825–0.233 μg/mL，检测限为0.0466 ng/mL（S/N = 3）。这项工作展示了钙钛矿氧化物及其异质结构在先进光电化学生物传感应用中的潜力。