DNA Triangular Prism Based Tripedal Walking Along Triplex‐Forming Track

We herein propose a smart tripedal DNA walking nanomachine based on the nanostructure transition of DNA triangular prism (TPDNA), which performs satisfactorily for highly sensitive analysis of miRNA biomarkers. Split DNAzyme sequences are integrated in the TPDNA with suppressed activity. With target sequence-mediated catalytic hairpin assembly, TPDNA structural transformation relives the blockage and the triple active DNAzyme units function as the driver of the DNA nanomachine. In addition, the triplex-forming track on the surface of electrode suffers the cleavage reaction and the declined signal is utilized to indicate the level of target miRNA. The track can be further regenerated by simply changing pH conditions, improving the stability and reducing the cost. Excellent performances are well validated and the feasibilities in complex biological samples are also demonstrated. This strategy integrates the advantages of DNA dynamic nanomachine and DNA structural transition, which holds great potential for nucleic acid-based studies and clinical diagnostics.