The quantitative detection of microRNAs (miRNAs) is crucial for the diagnosis of cancers, while the traditional methods experience complicated procedure and restricted signal gain. In this study, we have established an ultrasensitive electrochemical biosensor by combining target-induced hybridization reaction and signal amplification strategy for the detection of miRNA-21. The signal amplification is achieved through employing double-stranded DNA as scaffolds for methylene blue (MB) and using polypyrrole@gold nanocomposite (ppy@AuNPs) as the electrochemical catalysts for further enhancing signal. Therefore, this proposed electrochemical platform displayed an analytical performance with a wide linear range from 10 fM to 100 nM and a low detection limit down to 5.4 fM. The excellent selectivity allows the biosensor to discriminate miRNA-21 from other miRNAs, even the one base-mismatched sequence. Moreover, this nanoelectrocatalyst-based platform exhibited good reproducibility and remarkable storage stability, which shows great potential for miRNA-21 detection.

You have access to this article

Please wait while we load your content... Something went wrong. Try again?