College of Electrical Engineering, North China University of Science and Technology, Tangshan, P.R. China.
School of Data Science, TongRen University, TongRen, P.R. China.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2023 Aug;40(8):1059-1073. doi: 10.1080/19440049.2023.2240435. Epub 2023 Aug 1.
In this study, a novel electrochemical aptamer sensor for detecting ochratoxin A (OTA) was constructed. First, a gold-copper alloy film was prepared electrochemical deposition, and copper was selectively dissolved in constant potential mode for obtaining the nano-porous gold modified screen-printed carbon electrodes (NPG/SPCE). Then, 2-mercaptoethylamine was dropped on the NPG/SPCE surface and Au-S covalent bonds were formed for immobilizing the metal. Glutaraldehyde as cross-linking agent was added, which resulted in immobilization and attachment of PAMAM to the 2-mercaptoethylamine through the dehydration condensation reaction. During the preparation process, the nano-porous gold and PAMAM-modified layers were characterized by SEM, XRD, and IR spectroscopy, respectively. The characterization results showed that the nano-porous gold and PAMAM composite films were successfully modified. Finally, the OTA aptamer was cross-linked with PAMAM by glutaraldehyde to complete construction of the Apt/PAMAM/NPG/SPCE sensor. The electrochemical performance of this sensor was tested in ochratoxin A solutions with the DPV method. The results showed that the sensor's reproducibility, stability, and specificity were good. The spiked recoveries in red wine ranged from 99.65%∼101.6%, with a linear range of 0.5 ng/mL∼20 ng/mL and a minimum detection limit of 0.141 ng/mL. Thus, the novel biosensor may provide a promising tool for the trace detection of OTA.
本研究构建了一种用于检测赭曲霉毒素 A (OTA) 的新型电化学适体传感器。首先，通过电化学沉积制备了金铜合金膜，然后采用恒电位模式选择性溶解铜，得到修饰有纳米多孔金的丝网印刷碳电极 (NPG/SPCE)。接着，将 2-巯基乙胺滴加到 NPG/SPCE 表面，形成 Au-S 共价键，用于固定金属。加入戊二醛作为交联剂，通过脱水缩合反应将 PAMAM 固定和附着在 2-巯基乙胺上。在制备过程中，分别通过 SEM、XRD 和 IR 光谱对纳米多孔金和 PAMAM 修饰层进行了表征。表征结果表明，成功地修饰了纳米多孔金和 PAMAM 复合膜。最后，通过戊二醛将 OTA 适体交联到 PAMAM 上，完成了 Apt/PAMAM/NPG/SPCE 传感器的构建。通过 DPV 法测试了该传感器在 OTA 溶液中的电化学性能。结果表明，该传感器具有良好的重现性、稳定性和特异性。在红酒中的加标回收率在 99.65%∼101.6%之间，线性范围为 0.5 ng/mL∼20 ng/mL，检测限低至 0.141 ng/mL。因此，这种新型生物传感器可能为 OTA 的痕量检测提供一种有前途的工具。
