AND-gated logic detection of dual miRNAs in living cells and tissues via 3D catalytic hairpin assembly

The development of a DNA-based logic device capable of simultaneously detecting two microRNAs (miRNAs) has the potential to enhance the accuracy of cancer diagnosis. However, existing approaches are hindered by slow response times, limited sensitivity, and inadequate cellular delivery. In this study, we integrated logic operations with 3D catalytic hairpin assembly (3D-CHA) to devise a sensing system for the AND-gated analysis of miR-21 and miR-155 in living cells and tissues. We utilized two DNA nanospheres, designated AN1 and AN2, which, upon the presence of both miRNA inputs, release an initiator via strand displacement, consequently triggering 3D-CHA between AN1 and AN2 and generating an amplified output. Our findings demonstrate that the AN nanoprobe facilitates the logical analysis of dual miRNAs in buffers, living cells, and tissues, offering effective cellular delivery, nuclease resistance, heightened sensitivity, and rapid response time. The AN nanoprobe represents a promising diagnostic tool for the accurate detection of breast cancer and exhibits considerable potential for clinical applications.