A Simple Electrochemical Biosensor For Rapid Detection Of Microrna Based On Base Stacking Technology And Enzyme Amplification

MicroRNAs (miRNA) are pivotal regulators of a wide range of cellular processes and have been identified as promising cancer biomarkers due to their stable presence in serum. In this study, we have developed a simple and rapid electrochemical biosensing strategy for detection of miRNA based on base stacking hybridization technology and enzyme amplification. In the presence of target miRNA-122, miRNA-122 can hybridize with the capture probes immobilized on the electrode surface, then the biotinylated detection probes hybridize with the remaining part of miRNA-122. Consequently, strong base stacking effect can make the target sequence, detection probes and capture probes have a good and stable combination. Finally, the streptavidin-alkaline phosphatase (ST-AP) binding with biotinylated detection probes catalyzes the hydrolysis of the substrate a-naphthyl phosphate (alpha-NP). The electrochemical biosensor could detect miRNA down to 0.4 pM with a linear range from 1 pM to 100 nM, and exhibited good specificity and reproducibility. This developed sensing strategy may be readily expanded to other miRNA detection and provide a promising tool for the basic research and clinical application.