Programmable DNAzyme walkers on gold nanoplatforms: From rational design to bioimaging/biosensing breakthroughs.

DNA walkers play a strategic role in precision medicine for applications such as single-cell analysis and tumor microenvironment modulation, yet face bottlenecks in stability, efficiency, and physiological adaptability. A DNA walker primarily comprises a walking strand, track, and driving force. DNAzyme-driven walkers achieve autonomous movement via enzymatic catalysis, eliminating reliance on external energy. The AuNP-DNAzyme synergy overcomes bottlenecks via surface plasmon resonance, thiol chemistry, and nanoconfinement for signal enhancement, dense DNA modification, and enzyme stabilization. Compared to DNA fuel or protease-powered walkers, this strategy enhances processivity and stability while reducing costs. This review is structured around "structure-performance-application": it first outlines the components of DNA walkers and the structural roles of AuNPs, then discusses performance optimization through 3D tracks and DNAzyme tuning, and finally summarizes applications in molecular imaging and biosensing. Future development trends of DNA walkers have been delved into, and their research prospects have been presented in this article, with a focus on theranostic integration and in vivo dynamic imaging, positioning DNA walkers as intelligent platforms for precision diagnostics and targeted therapy. STATEMENT OF SIGNIFICANCE: This review highlights the transformative potential of DNAzyme-driven DNA walkers, which leverage the autonomous catalytic activity of DNAzymes to achieve unparalleled operational efficiency, stability, cost-effectiveness, and programmability compared to conventional fuel strand- or protease-powered systems. Central to their advancement is the integration of gold nanoparticles (AuNPs), whose exceptional biocompatibility, large surface area, and versatile surface functionalization capabilities enable robust construction and enhanced performance of DNA walker platforms. By systematically outlining the synergy between DNAzyme walkers and AuNPs, this work underscores their groundbreaking applications in biosensing and molecular imaging, offering ultrasensitive detection and precise spatial resolution for biomedical research. Furthermore, the discussion on future trends positions DNA walkers as pivotal tools poised to drive innovation in nanotechnology, diagnostics, and targeted therapeutics, bridging fundamental science with real-world clinical and analytical challenges.