Rapid and ultrasensitive detection of microRNA based on strand displacement amplification-mediated entropy-driven circuit reaction

MicroRNAs (miRNAs) are potential biomarkers for early diagnosis of various diseases. Herein, we reported, for the first time, a simple and rapid fluorescence strategy for highly sensitive and specific detection of miRNA based on strand displacement amplification-mediated entropy-driven circuit reaction (SDA-EDCR). The binding of target miRNA with a hairpin template initiated SDA to cyclically generate large amounts of triggers. Then, the triggers could initiate EDCR to release report strands and cyclic reuse triggers, resulting in a significantly amplified fluorescence signal toward miRNA detection. The isothermal amplification method exhibited a much wider linear range from 1 fM to 10 nM with low detection limit of 0.18 fM. The strategy could also be applied to detect the miRNA in complex sample matrix with satisfied results. Moreover, the two-layer amplification strategy was time-saving in comparison with most of previously reported cascade amplification methods Therefore, this novel approach provides a general platform to develop simple, rapid, cost-effective, sensitive, and selective nucleic acids assay for various important applications in bioanalysis and clinical diagnosis.