School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China.
Medical Laboratory Science, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, 533000, China; Key Laboratory of Clinical Molecular Diagnosis and Research for High Incidence Diseases in Western Guangxi, Guangxi, 533000, China.
Anal Chim Acta. 2024 May 8;1302:342492. doi: 10.1016/j.aca.2024.342492. Epub 2024 Mar 16.
The rational design of DNA tracks is an effective pathway to guide the autonomous movement and high-efficiency recognition in DNA walkers, showing outstanding advantages for the cascade signal amplification of electrochemical biosensors. However, the uncontrolled distance between two adjacent tracks on the electrode could increase the risk of derailment and interruption of the reaction. Hence, a novel four-way balanced cruciform-shaped DNA track (C-DNT) was designed as a structured pathway to improve the effectiveness and stability of the reaction in DNA walkers. In this work, two kinds of cruciform-shaped DNA were interconnected as a robust structure that could avoid the invalid movement of the designed DNA walker on the electrode. When hairpin H2 was introduced onto the electrode, the strand displacement reaction (SDR) effectively triggered movements of the DNA walker along the cruciform-shaped track while leaving ferrocene (Fc) on the electrode, leading to a significant enhancement of the electrochemical signal. This design enabled the walker to move in an excellent organized and controllable manner, thus enhancing the reaction speed and walking efficiency. Compared to other walkers moving on random tracks, the reaction time of the C-DNT-based DNA walker could be reduced to 20 min. Lead ion (Pb) was used as a model target to evaluate the analytical performance of this biosensor, which exhibited a low detection limit of 0.033 pM along with a wide detection ranging from 0.1 pM to 500 nM. This strategy presented a novel concept for designing a high-performance DNA walker-based sensing platform for the detection of contaminants.
DNA 轨道的合理设计是引导 DNA walker 自主运动和高效识别的有效途径，在电化学生物传感器的级联信号放大方面表现出突出的优势。然而，电极上相邻轨道之间不受控制的距离可能会增加脱轨和反应中断的风险。因此，设计了一种新颖的四向平衡十字形 DNA 轨道（C-DNT）作为结构化途径，以提高 DNA walker 中反应的有效性和稳定性。在这项工作中，两种十字形 DNA 相互连接形成一个坚固的结构，可以避免设计的 DNA walker 在电极上的无效运动。当发夹 H2 被引入电极时，链置换反应（SDR）有效地触发了 DNA walker 沿着十字形轨道的运动，同时将二茂铁（Fc）留在电极上，从而显著增强了电化学信号。这种设计使 walker 能够以优异的组织和可控的方式移动，从而提高了反应速度和行走效率。与在随机轨道上移动的其他 walker 相比，基于 C-DNT 的 DNA walker 的反应时间可以缩短至 20 分钟。铅离子（Pb）被用作模型目标来评估该生物传感器的分析性能，其检测限低至 0.033 pM，检测范围从 0.1 pM 到 500 nM 很宽。该策略为设计基于高性能 DNA walker 的用于检测污染物的传感平台提供了一个新的概念。
