DNA nanoframework-confined well-organized catalytic hairpin assembly for highly sensitive and specific detection of...

MiRNAs (miRs) are emerging as valuable biomarker for disease monitoring, diagnosis, and prognostic evaluation, particularly cancer. Herein, we have developed a highly sensitive and specific fluorescent biosensor for miRNA detection using a DNA nanoframework-confined well-organized catalytic hairpin assembly (DOCO-CHA) system. The biosensor leverages DNA dendrimers, self-assembled from Y-DNA1 and Y-DNA2, to provide abundant intercalation sites for immobilizing a large number of catalytic hairpin assembly (CHA) probes, thereby enhancing the reaction environment and improving detection efficiency. The DOCO-CHA system also demonstrated remarkable target recycling amplification, further enhancing sensitivity. Under optimal conditions, the biosensor achieved miR-21 detection with a detection limit of 16.4 pM. Moreover, the system exhibited excellent specificity and stability, with recoveries of 96.3 %-99.3 % in real serum sample analysis. These findings suggest that the developed DOCO-CHA system holds great potential for miRNA-based diagnostics.