An Autonomous Self-Cleavage DNAzyme Walker for Live Cell MicroRNA Imaging.

The autonomous DNA walker can be applied in the direction conduction and amplification of detection signals due to its unique characteristic of continuous mechanical motion. DNAzyme walker is a kind of special DNA walker that is propelled by DNAzyme. Herein, we describe a designed model named Self-Cleavage DNAzyme Walker (SCDW), in which the DNAzyme and substrate were designed as tracks, and the target served as a walker. In short, the target (walker) walks along the tracks (DNAzyme-substrate chimera) step by step. At each step, the track can be activated and then self-cleaved, resulting in continuous mechanical movement. We tested the performance of the SCDW in a tube and in live cells. The results showed that it could detect the expression level and change of target miRNA in vitro and in live cells with high sensitivity and specificity. It is speculated that such a design may be extensively used to assist in disease diagnosis as well as fundamental biomedical research.