A novel magnetic controlled photoelectrochemical (PEC) sensing system was designed for sensitive detection of prostate-specific antigen (PSA) using reduced graphene oxide-functionalized BiFeO₃ (rGO-BiFeO₃) as the photoactive material and target-triggered hybridization chain reaction (HCR) for signal amplification. Remarkably enhanced PEC performance could be obtained by using rGO-BiFeO₃ as the photoelectrode material due to its accelerated charge transfer and improved the visible light absorption. Additionally, efficient and simple operation could be achieved by introducing magnetic controlled flow-through device. The assay mainly involved in anchor DNA-conjugated magnetic bead (MB-aDNA), PSA aptamer/trigger DNA (Apt-tDNA) and two glucose oxidase-labeled hairpins (H1-GOx and H2-GOx). Upon addition of target PSA, the analyte initially reacted with the aptamer to release the trigger DNA, which partially hybridized with the anchor DNA on the MB. Thereafter, the unpaired trigger DNA on the MB opened the hairpin DNA structures in sequence and propagated a chain reaction of hybridization events between two alternating hairpins to form a long nicked double-helix with numerous GOx enzymes on it. Subsequently, the enzymatic product (H₂O₂) generated and consumed the photo-excited electrons from rGO-BiFeO₃ under visible light irradiation to enhance the photocurrent. Under optimal conditions, the magnetic controlled PEC sensing system exhibited good photocurrent responses toward target PSA within the linear range of 0.001 − 100 ng/mL with a detection limit of 0.31 pg/mL. Moreover, favorable selectivity, good stability and satisfactory accuracy were obtained. The excellent analytical performance suggested that the rGO-BiFeO₃-based PEC sensing platform could be a promising tool for sensitive, efficient and low cost detection of PSA in disease diagnostics.

设计了一种新颖的磁控光电化学（PEC）传感系统，用于以还原型氧化石墨烯官能化的BiFeO ₃（rGO-BiFeO ₃）作为光敏材料和目标触发的杂交链反应（HCR ）灵敏检测前列腺特异性抗原（PSA））进行信号放大。通过使用rGO-BiFeO ₃可以获得明显增强的PEC性能由于其加速了电荷转移并改善了可见光吸收，因此作为光电极材料。另外，通过引入磁控流通装置可以实现有效而简单的操作。该测定法主要涉及结合锚定DNA的磁珠（MB-aDNA），PSA适体/触发DNA（Apt-tDNA）和两个葡萄糖氧化酶标记的发夹（H1-GOx和H2-GOx）。加入靶标PSA后，分析物开始与适体反应以释放触发DNA，该触发DNA与MB上的锚定DNA部分杂交。此后，MB上未配对的触发DNA依次打开了发夹DNA结构，并在两个交替的发夹之间传播了杂交事件的链式反应，形成了带有许多GOx酶的长切口双螺旋。随后，酶产物（H₂ O ₂）在可见光照射下从rGO-BiFeO ₃产生并消耗了光激发电子，从而增强了光电流。在最佳条件下，磁控PEC传感系统在0.001-100 ng / mL的线性范围内对目标PSA表现出良好的光电流响应，检出限为0.31 pg / mL。此外，获得了有利的选择性，良好的稳定性和令人满意的精度。出色的分析性能表明，基于rGO-BiFeO ₃的PEC传感平台可以成为在疾病诊断中灵敏，高效且低成本检测PSA的有前途的工具。