The toehold-mediated strand displacement reaction plays a crucial role in the functionality of DNA nanodevices. However, the reaction's velocity is heavily reliant on the length of the toehold region. A shorter toehold can impede the speed and completeness of the reaction. This study utilized DNA phosphorothioate modification to analyze its impact on these significant processes. The findings revealed that a shorter toehold (Toehold < 5 nt) accelerates the initial strand release, thus expediting the entire reaction when modified with phosphorothioate. Conversely, a longer toehold (Toehold > 4 nt) with phosphorothioate modification enhances the displacement reaction's extent. Furthermore, this newfound knowledge was applied to DNA-based reaction systems such as catalytic hairpin assembly and DNA probabilistic circuit, demonstrating that phosphorothioate usage can effectively regulate and enhance the functionality of these systems. This development holds promise for the future advancements in biocomputing, nanotechnology, and gene therapy.

中文翻译：

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通过硫代磷酸酯修饰改善对脚趾介导的链置换反应的动态控制


脚趾介导的链置换反应在 DNA 纳米器件的功能中起着至关重要的作用。然而，反应的速度在很大程度上取决于脚趾区域的长度。较短的脚趾支撑会阻碍反应的速度和完整性。本研究利用 DNA 硫代磷酸酯修饰来分析其对这些重要过程的影响。研究结果表明，较短的脚趾 （Toehold < 5 nt） 加速了初始链的释放，从而在用硫代磷酸酯修饰时加速了整个反应。相反，硫代磷酸酯改性的较长脚趾 （Toehold > 4 nt） 增强了置换反应的程度。此外，这些新发现的知识被应用于基于 DNA 的反应系统，例如催化发夹组装和 DNA 概率电路，表明硫代磷酸盐的使用可以有效调节和增强这些系统的功能。这一发展为生物计算、纳米技术和基因治疗的未来发展带来了希望。