School of Chemistry and Materials Engineering, Xinxiang University, Xinxiang 453003, China.
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Bioelectrochemistry. 2023 Oct;153:108494. doi: 10.1016/j.bioelechem.2023.108494. Epub 2023 Jun 24.
Electrochemical aptasensor has been broadly advanced for nucleic acid detection. However, it is a long-term goal to design an aptasensor with high specificity, flexibility, and simplicity. In this work, we develop a strategy of triblock DNA probe, which consists of two DNA probes at both ends and ployA fragments in the middle as probe-polyA-probe. PolyA fragment has high affinity to the surface of gold electrode, so it can be assembled on the electrode surface via polyA instead of traditional Au-S bonds. When the target DNA is simultaneously hybridized with the two capture probes, the hybridization stability can be improved due to the strong base stacking effect. [Ru(NH)], as signal probe, can be electrostatically adsorbed on the negatively charged DNA skeleton. A wide linear range (10 pM-10 μM) is obtained with a detection limit of 2.9 pM. Our electrochemical aptasensor has good repeatability, stability, and specificity. More importantly, the electrochemical sensor can successfully detect DNA in human serum samples, which proves its practical value and extensive applicability in complex environment.
电化学适体传感器已广泛应用于核酸检测。然而，设计具有高特异性、灵活性和简单性的适体传感器是一个长期目标。在这项工作中，我们开发了一种三嵌段 DNA 探针策略，它由两端的两个 DNA 探针和中间的聚 A 片段组成，即探针-聚 A-探针。聚 A 片段与金电极表面具有高亲和力，因此可以通过聚 A 而不是传统的 Au-S 键组装在电极表面上。当目标 DNA 与两个捕获探针同时杂交时，由于强碱基堆积效应，杂交稳定性可以提高。[Ru(NH₃)₅]²⁺作为信号探针，可以通过静电吸附在带负电荷的 DNA 骨架上。该电化学适体传感器具有较宽的线性范围（10 pM-10 μM）和较低的检测限（2.9 pM）。我们的电化学适体传感器具有良好的重复性、稳定性和特异性。更重要的是，电化学传感器可以成功地检测人血清样本中的 DNA，证明了其在复杂环境中的实际价值和广泛适用性。
