A robust DNA walker for simplified, rapid, and sensitive detection of HBV DNA in blood

Although preventive vaccine is available, HBV infection continues to be a global health challenge, especially in rapid and accurate screening in resource-limited regions due to underdeveloped infrastructures. In this study, we developed a self-powered DNA walker system integrating AuNPs and DNAzyme for direct detection of HBV DNA in blood. In the presence of HBV DNA, this DNA walker was activated to start autonomous and rapid movement on AuNPs driven by DNAzyme, and the amplified fluorescent signals were generated and detected. With remarkable specificity and biostability, this DNA walker system was validated by detecting HBV DNA in blood samples from patients chronically infected with HBV. Our results demonstrated that the HBV DNA load of 20,000 IU/mL in plasma could be detected by our strategy, and there was a strong correlation (Pearson's r = -0.86) between the fluorescence intensity measured by the DNA walker and the Ct value. Collectively, we established a simple, efficient, and rapid detection strategy for HBV DNA in the blood, with substantial potential application in resource-limited countries/regions.