High-fidelity intracellular imaging of multiple miRNAs via stimulus-responsive nanocarriers and catalytic hairpin assembly.

An advanced nanoplatform was developed by integrating catalytic hairpin assembly (CHA) with glutathione-responsive nanocarriers, enabling superior imaging of dual cancer-related miRNAs. Two distinct CHA circuits for the sensing of miRNA-21 and miRNA-155 were functionalized on biodegraded MnO 2 . In the presence of GSH and the corresponding miRNAs, the degraded MnO 2 released the DNA cargos, activating the CHA circuits and recovering the fluorescence. This approach offers a reliable sensing performance with highly selective cell-identification capacity, positioning it as a pivotal tool for imaging multiple biomarkers in living cells.