miRNAs, a class of endogenous noncoding RNAs, are involved in many crucial biological processes, which have emerged as a new set of biomarkers for disease theranostics. Exploring efficient signal amplification strategy is highly desired to pursue a highly sensitive miRNA biosensing platform. DNA nanotechnology shows great promise in the fabrication of amplified miRNA biosensors. In this work, a novel DNA walking and rolling nanomachine is developed for highly sensitive and selective detection of miRNA. Particularly, this approach programs two forms of dynamic DNA nanomachines powered by corresponding enzymes, which are well integrated. It is able to achieve a limit of detection as low as 39 × 10⁻¹⁸ m, along with excellent anti‐interfering performance and clinical applications. In addition, by designing pH‐controlled detachable intermolecular DNA triplex, the main sensing elements can be conveniently reset, which fulfills the requirements of point‐of‐care profiling of miRNA. The high consistency between the proposed approach and quantitative real‐time polymerase chain reaction validates the robustness and reliability. Therefore, it is anticipated that the DNA walking and rolling nanomachine has attractive application prospects in miRNA assay for biological researches and clinical diagnosis.

中文翻译：

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DNA步行和滚动纳米机电化学检测miRNA

miRNA是一类内源性非编码RNA，它参与了许多关键的生物学过程，这些生物学过程已成为疾病治疗学的一组新的生物标记。为了追求高灵敏度的miRNA生物传感平台，迫切需要探索有效的信号放大策略。DNA纳米技术在扩增miRNA生物传感器的制造中显示出巨大的希望。在这项工作中，开发了一种新型的DNA行走和滚动纳米机器，用于高度敏感和选择性地检测miRNA。特别地，这种方法对由相应酶驱动的两种形式的动态DNA纳米机器进行了编程，它们被很好地整合了。能够实现低至39×10 ^-18 m的检测极限，以及出色的抗干扰性能和临床应用。此外，通过设计pH值控制的可分离分子间DNA三链体，可以方便地重置主要的传感元件，从而满足miRNA即时点分析的要求。所提出的方法与定量实时聚合酶链式反应之间的高度一致性验证了稳健性和可靠性。因此，可以预期的是，DNA行走和滚动纳米机器在用于生物学研究和临床诊断的miRNA测定中具有诱人的应用前景。