Manipulations of DNA four-way junction architecture and DNA modified Fe3O4@Au nanomaterials for the detection of miRNA

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.