A novel fluorescence probe of dsDNA-templated copper nanoclusters for quantitative detection of microRNAs

We have developed a facile and label-free method for sequence-specific microRNA detection using fluorescent dsDNA-templated copper nanoclusters as signal indicators. It is designed such that, the miRNA targets are transferred to the oligonucleotide reporters and act as the scaffold for the synthesis of fluorescent copper nanoclusters via an isothermal exponential amplification reaction, in which the unimolecular DNA designed for miRNA targets is employed as the amplification template with polymerases and nicking enzymes as mechanical activators. Under the selected conditions, the proposed assay allowed sensitive and selective detection of miRNAs with a linear range from 1 pM to 10 nM.