miRNAs have attracted increased attention as biomarkers, which have strong associations with diseases like cancers. Herein, we have constructed DNA four-way junction architecture on the surface of electrode for ultrasensitive electrochemical detection of miRNA. Isothermal duplex-specific nuclease catalyzed reaction and nicking endonuclease catalyzed reaction are performed on the synthesized novel magnetic nanomaterials and the formed DNA junctions, respectively. Besides the enzymatic reaction cycles, TCEP mediated electrochemical amplification is integrated for improvement of the sensitivity. This method not only achieves attomolar sensitivity, high selectivity and practical utility have also been confirmed. Therefore, the proposed approach is supposed to provide a powerful tool for miRNA related biological researches and clinical applications.

miRNA作为生物标记物已引起越来越多的关注，它与癌症等疾病有着密切的联系。本文中，我们在电极表面构建了DNA四向连接结构，用于miRNA的超灵敏电化学检测。等温双链体特异性核酸酶催化反应和切口内切核酸酶催化反应分别对合成的新型磁性纳米材料和形成的DNA结进行。除酶促反应循环外，还整合了TCEP介导的电化学扩增，以提高灵敏度。该方法不仅实现了对摩尔的灵敏度，还具有高选择性和实用性。因此，拟议的方法应该为miRNA相关的生物学研究和临床应用提供强大的工具。