A multiple-cross self-powered sensor based on photo-assisted zinc-air battery for spatio-temporal reconciliated...

The development of a spatio-temporal coordination and multiple-cross detection platform is crucial for the highly accurate assay in complex sample or varied environments. In this study, a sensitive and accurate dual-mode self-powered electrochemical sensor (SPES) was constructed based on the Z-scheme heterojunction-promoted photo-assisted zinc-air battery (ZAB) and electrochromic (EC) technology for the multiple-cross quantitative analysis of gallic acid (GA). With AgBr/BiFeO₃ Z-scheme heterojunction as the photocathode, the photo-assisted ZAB functions as an energy collection and conversion device to realize the SPES with enhanced energy conversion efficiency. Furthermore, this platform enables the sensitive and selective detection of GA with the use of molecular imprinting technology. In detail, the presence of GA initiates its binding to the molecularly imprinted cavity, subsequently hindering electron transfer on the electrode surface. This not only reduces output power density but also hinders electron participation in the electrochromic reaction, leading to a color change. By combining the advantages of SPES and EC technology, this platform enables simultaneous collection and multiple cross-validation of electrochemical signals and visual signals, thereby enhancing detection accuracy. The limit of detection of SPES and EC was found to be 1.2 × 10^-10 M and 1.9 × 10^-10 M (S/N = 3), respectively. This research offers a new idea for the construction of a highly accurate dual-mode sensing platform with multiple-cross signals and convenient operation.