A Multifunctional Tetrahedral DNA Nanostructure for the Simultaneous Sensitive Detection and Imaging of miRNA and Zinc Ions in Living Cells

In this study, a multifunctional tetrahedral DNA nanostructure (MTDN) was constructed by assembling different functional modules for the simultaneous sensitive detection and imaging of targets miRNA-21 and Zn²⁺ in living cells related to liver cancer. Impressively, compared with the traditional detection strategy for miRNA-21 and Zn²⁺ with low sensitivity, this strategy employs autocatalytic hairpin assembly (ACHA) to rapidly self-assemble into linear tetrahedral DNA nanostructures (LTDNS) by activating the functional module on MTDN to produce two strong fluorescent signals for sensitive detection of miRNA-21 and Zn²⁺ with detection limits of 0.79 pM and 33.46 nM, respectively, which were much lower than the reported literature. More importantly, LTDNS with a spatial confinement effect and low diffusion coefficient could achieve accurate localization imaging of targets to significantly enhance imaging clarity. The strategy provides an innovative method for simultaneous sensitive detection and accurate imaging of multiple biomarkers and has broad application prospects in early disease diagnosis.