Programmable DNA Framework-Based Logic-Gated Dual-Distance Regulation for Photoelectrochemical Multiplex and Sensitive Detection of Waterborne Viruses

Multiplex and sensitive detection of viruses in aquatic environments is of great significance for water safety monitoring. The application of photoelectrochemical (PEC) sensors in environmental analysis has been hindered by the recombination of photogenerated charges and signal cross-interference at single recognition interfaces. In this study, a programmable DNA-framework-mediated logic-gate-functionalized dual-distance-regulated PEC sensor was developed and successfully implemented for the detection of multiple viruses in water environments. By programming DNA frameworks, logic operation units such as OR, AND, OR-AND, and AND-OR were constructed to address the issue of cross-interference in multiplex detection signals. Additionally, dual-distance regulation, triggered by the signal factors of target nucleic acid amplification, serves to enhance the signal response and counteract the issue of low signal intensity caused by photogenerated charge recombination. The mechanisms of DNA conformational change-induced multiplex signal transduction and dual-distance regulation for signal enhancement were systematically elucidated. The constructed sensor exhibited a superior linear response to virus nucleic acids in the concentration range of 0.001-500 nM, with a detection limit as low as 7.7 fM. Furthermore, it demonstrated promising analytical performance for multiple coexisting virus nucleic acids in actual water samples. This study is anticipated to advance the application of single-interface PEC sensors in multiplex environmental analysis.