A leakage-resistant catalytic hairpin assembly for ultrasensitive detection of miRNA-146a in systemic lupus erythematosus

Abstract

a leakage-resistant catalytic hairpin assembly (CHA) was developed for ultrasensitive detection of miRNA-146a in systemic lupus erythematosus. miRNA-146a can trigger the hybridization chain reaction (HCR) and form a long duplex. The two side chain of duplex can cleave the leakage-resistant hairpin and induce the CHA reaction. Simultaneously, the produced DNA fragment can also circularly catalyze and fasten the HCR reaction. The leakage-resistant hairpin used for CHA was firstly locked by substrate strand DNA. The special design inhibits the circuit leakage between hairpins, causing lower background than those traditional hairpin design. The limit of detection was improved to 1 fM by HCR coupled leakage-resistant CHA strategy. Significantly, it possibly provided an alternative strategy to prevent the leakage between hairpins. In addition, the incubation time had been obviously shorted by the recycle using of cleaved DNA fragments. It also showed a great specificity for miRNA-146a towards other similar sequence and great potential in early screening and clinical diagnosis.