A hairpin DNAs-fueled nanoflare for simultaneous illuminating two microRNAs in drug-induced nephrotoxic cells with target catalytic recycling amplification
The detection of specific extracellular microRNAs (miRNAs) is beneficial for the prediction of drug-induced kidney injury. Here, a novel hairpin DNAs-fueled nanoflare has been developed for simultaneous detection of drug-induced nephrotoxicity-related miRNA-21 and miRNA-200c with target catalytic recycling amplification. The nanoflare utilizes gold nanoparticle (AuNP) as the highly efficient quencher to ensure a low background signal. With the help of fueled hairpin DNA, the miRNA targets can be served as catalysts for the assembly of DNA duplexes. Therefore, the nanoflare can response to miRNAs to yield signal outputs of 1: n (target: signal) rather than equivalent reaction ratio of 1: 1, achieving signal amplified detection of low-abundant miRNAs. The targets can be concurrently detected with the detection limits of 18.1 and 21.1 pM for miRNA-21 and miRNA-200c, respectively, which is approximately 2 orders of magnitude lower than the non-catalytic probes. Additionally, this nanoflare offers high selectivity for determination between perfectly matched targets and single-base mismatched targets. It should be noted that the nanoflare has been successfully employed to predict drug-induced nephrotoxicity by the detection of miRNAs in culture media excreted from the drug-treated renal cells using a fluorescent microplate reader. Our hairpin DNAs-fueled nanoflare can also accurately detect the divergence of miRNA-21 and miRNA-200c between drug-treated nephrotoxic cells and tumor cells, demonstrating the promising potential for exploring the pathogenesis of drugs and auxiliary diagnosis of drug-induced nephrotoxicity.