Supramolecular DNA Nanodevice Assembled via RCA and HCR Cascade Reaction on Tetrahedral DNA Nanostructure for Sensitive Detection and Intracellular Imaging of Dual-miRNAs Associated with Liver Cancer

Herein, a supramolecular DNA nanodevice was formed via the rolling circle amplification (RCA) and hybridization chain reaction (HCR) cascade reaction on a tetrahedral DNA nanostructure (TDN) to achieve simultaneous sensitive detection and intracellular imaging of dual-miRNAs related to liver cancer. The supramolecular DNA nanodevice effectively addressed the limitations of low probe loading capacity in traditional TDN nanodevices by enriching plenty of signal probes around a single TDN, significantly enhancing the fluorescence signal. Impressively, the supramolecular DNA nanodevice with a TDN fulcrum and dense DNA structure imparted the nanodevice with strong rigidity, ensuring the stability of the signal probes to decrease aggregation quenching for further increasing the fluorescence response. Consequently, the biosensor based on supramolecular DNA nanodevice enabled simultaneous and sensitive detection of miRNA221 and miRNA222, and further achieved accurate in situ intracellular imaging of miRNA221 and miRNA222, displaying significantly improved imaging capabilities compared to traditional TDN-based nanodevices. More importantly, simultaneous and precise intracellular imaging of miRNA221 and miRNA222 could effectively distinguish hepatocellular carcinoma cells with different degrees of metastasis from human normal liver cells, providing more precise information for the diagnosis and development of hepatocellular carcinoma.