DNA walkers, as intelligent artificial DNA nanomachines, have been widely used as efficient nucleic acid amplification tools that the detection sensitivity can be improved by incorporating DNA walkers into DNA biosensors. Nevertheless, since the premature release or flameout in a region of locally exhausted substrate, the walking efficiency of DNA walkers remains unsatisfactory. In this work, we design a smart tripedal DNA walker that is formed by target-initiated catalyzed hairpin assembly (CHA), which can move along the DNA duplex tracks on electrode driven by toehold-mediated DNA strand displacement (TMSD) for transduction and amplification of electrochemical signals. Emphatically, this flexible tripedal DNA walker is capable of walking freely along the tracks with unconstrained walking range. Moreover, the design of multi-legged walker can weaken the derailment of leg DNA and shorten the moving time on electrode, ensuring the processive walking with high efficiency. Additionally, the persistent walking of tripedal walker is driven by cascading TMSD, which eliminates the defects of high cost and instability of enzyme-assisted amplification technology. Therefore, the tripedal DNA walker-based electrochemical biosensor has enormous potential for the applications of OTA detection, and reveals a new avenue for food safety analysis and clinical diagnosis.

中文翻译：

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Toehold 介导的 DNA 链置换驱动的超快速三足 DNA Walker 用于赭曲霉毒素 A 的超灵敏和无标记电化学检测

DNA步行器作为智能人工DNA纳米机器，已被广泛用作高效的核酸扩增工具，通过将DNA步行器集成到DNA生物传感器中可以提高检测灵敏度。然而，由于在局部耗尽的底物区域过早释放或熄火，DNA步行者的步行效率仍然不能令人满意。在这项工作中，我们设计了一种智能三足 DNA 步行器，由目标启动的催化发夹组装 (CHA) 形成，它可以沿着电极上的 DNA 双链移动，由脚趾介导的 DNA 链置换 (TMSD) 驱动进行转导和放大电化学信号。值得一提的是，这款灵活的三足 DNA 步行器能够在不受限制的步行范围内沿着轨道自由行走。而且，多腿助行器的设计可以减弱腿部DNA的脱轨，缩短在电极上的移动时间，确保高效的进行性行走。此外，三足行走器的持续行走由级联TMSD驱动，消除了酶辅助扩增技术成本高和不稳定的缺陷。因此，基于三足DNA步行器的电化学生物传感器在OTA检测的应用中具有巨大的潜力，为食品安全分析和临床诊断开辟了一条新途径。消除了酶辅助扩增技术成本高、不稳定的缺陷。因此，基于三足DNA步行器的电化学生物传感器在OTA检测的应用中具有巨大的潜力，为食品安全分析和临床诊断开辟了一条新途径。消除了酶辅助扩增技术成本高、不稳定的缺陷。因此，基于三足DNA步行器的电化学生物传感器在OTA检测的应用中具有巨大的潜力，为食品安全分析和临床诊断开辟了一条新途径。