The application provides a miRNA imaging application method based on an endogenous
glutathione activated
DNA sensor for logic
cascade signal amplification. The technology constructs a "local catalytic hairpin
assembly DNA nanomachine", and triggers a
cascade reaction through endogenous
glutathione (GSH) and target miRNA-21: GSH cleaves the
disulfide bond on the GH1 hairpin, so that the conformation is changed into a metastable state H1, and then hybridizes with miRNA-21 to start
branch migration, releases miRNA-21 to circulate and catalyze H2 hairpin
assembly, and realizes exponential amplification of signals. FAM and BHQ1 on the H2 hairpin are spatially separated due to double-stranded formation, and the
fluorescence resonance energy transfer is released, so that a strong
fluorescence signal positively related to the concentration of miRNA-21 is generated. The method has high sensitivity (the
detection limit is 3.92 pM), high specificity and excellent stability, is suitable for high-fidelity imaging detection of miRNA in living cells, and provides an efficient tool for
cancer diagnosis and treatment integration.