College of Food Science and Technology, Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, Henan University of Technology, Zhengzhou 450001, China.
Henan Institute of Product Quality Supervision and Inspection, Zhengzhou 450008, China.
Anal Methods. 2023 Mar 9;15(10):1306-1314. doi: 10.1039/d2ay01747d.
Herein, an electrochemical biosensor was developed based on a magnetic separation strategy for the sensitive detection of the heavy metal Pb. The specific binding of Pb and the aptamer (Apt) is used to trigger the release of the complementary chain (cDNA) on the magnetic bead system. The cDNA completes base complementary pairing with hairpins HP1 and HP2 at the electrode to form a Y-DNA structure. Then, the Y-DNA runs continuously with the assistance of the signal tag methylene blue (MB) and the current signal increases. However, in the absence of Pb, cDNA cannot be released and the Y-DNA structure cannot be formed on the electrode, resulting in a relatively low current signal. Under the optimal experimental conditions, the reduced peak current difference (Δ) showed a good linear relationship with lg between 0.1 and 1000 nM, with a detection limit of 5.9 pM. In addition, the stability, reproducibility and detection capability of the sensors were investigated with satisfactory results.
本文基于磁分离策略开发了一种电化学生物传感器，用于灵敏检测重金属 Pb。Pb 与适配体 (Apt) 的特异性结合可触发磁珠系统上互补链 (cDNA) 的释放。cDNA 在电极上与发夹 HP1 和 HP2 完成碱基互补配对，形成 Y-DNA 结构。然后，在信号标签亚甲基蓝 (MB) 的协助下，Y-DNA 连续运行，电流信号增加。然而，在没有 Pb 的情况下，cDNA 无法释放，电极上无法形成 Y-DNA 结构，导致电流信号相对较低。在最佳实验条件下，还原峰电流差 (Δ) 与 lg 之间呈良好的线性关系，在 0.1 到 1000 nM 之间，检测限为 5.9 pM。此外，对传感器的稳定性、重现性和检测能力进行了研究，结果令人满意。
