Abstract A one-step triggered branched DNA nanostrucuture strategy was proposed for ultra-sensitive detection of microRNA (miRNA) based on two levels of hybridization chain reaction (HCR). The branched DNA nanostrucuture was produced through two HCR amplification procedures initiated by the target miRNA. After insertion of methylene blue (MB) into the base pairs, the concentration of miRNA can be obtained with a linear relationship from 10 fM to 50 pM by detecting the electrochemical signal of MB. The sensitivity for miRNA was significantly improved by HCR amplification, and the limit of detection was 2 fM. The proposed electrochemical biosensing strategy provides good reliability and ultra-high sensitivity as well as a satisfactory result for human serum sample. In addition, the one-step strategy greatly simplifies the operation step and reduce the systematic error, showing potential for real sample detection.

中文翻译：

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用于微RNA超灵敏电化学检测的一步触发分支DNA纳米结构

摘要 提出了一种基于两级杂交链反应（HCR）的单步触发分支DNA纳米结构策略，用于超灵敏检测microRNA（miRNA）。分支 DNA 纳米结构是通过两个由目标 miRNA 启动的 HCR 扩增程序产生的。将亚甲蓝 (MB) 插入碱基对后，通过检测 MB 的电化学信号，可以得到 miRNA 的浓度，从 10 fM 到 50 pM 呈线性关系。HCR扩增显着提高了对miRNA的灵敏度，检测限为2 fM。所提出的电化学生物传感策略为人血清样品提供了良好的可靠性和超高灵敏度以及令人满意的结果。此外，