Abstract A simple and novel method for immobilization of AS1411 aptamer, on Cu nanoparticles (NPs) electrode has been presented. For the first time, AS1411 aptamer without any functionalization was successfully immobilized on the Cu-NPs coating because of the interaction between guanine and Cu(111). The electrochemical responses determined that the current decreased, due to the strong electrostatic repulsive interaction between the negatively charged phosphate groups in aptamer strands and [Fe(CN)6]3−/4− in the electrolyte solution, leading to less electron transfer efficiency in the system and indicating the absorbance of G- quadruplex aptamer on the surface of Cu-NPs. In this work, 0.03 M was chosen as the Cu concentration, and the optimized aptamer concentration and incubation time on Cu-NPs were determined 10 µM and 20 min, respectively. Finally, the outstanding performance of the immobilized aptamer on the Cu-NPs coated surface was confirmed by quartz crystal microbalance. This study provides a low cost and easy approach for G-quadruplex aptamer trapping on the metal surface without incorporation of any ligand which could be helpful for fast and reliable cancer diagnosis in biomedical researches.

中文翻译：

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G-四链体适体在Cu沉积表面的电化学方法固定化

摘要 提出了一种将 AS1411 适配体固定在 Cu 纳米粒子 (NPs) 电极上的简单而新颖的方法。由于鸟嘌呤和Cu（111）之间的相互作用，没有任何功能化的AS1411适体首次成功地固定在Cu-NPs涂层上。由于适体链中带负电荷的磷酸基团与电解质溶液中的 [Fe(CN)6]3-/4- 之间的强静电排斥相互作用，电化学响应确定电流降低，导致电子转移效率降低。该系统并指示了 Cu-NPs 表面上 G-四链体适体的吸光度。在这项工作中，选择 0.03 M 作为 Cu 浓度，优化的适体浓度和 Cu-NPs 的孵育时间分别确定为 10 µM 和 20 分钟。最后，石英晶体微量天平证实了固定化适体在 Cu-NPs 涂层表面上的优异性能。该研究为在金属表面捕获 G-四链体适体提供了一种低成本且简单的方法，无需掺入任何配体，这可能有助于生物医学研究中快速可靠的癌症诊断。