A PMS-enhanced self-powered photoelectrochemical sensor based on dual-photoelectrode architecture for sensitive detection of carbofuran and acetamiprid.

A novel self-powered photoelectrochemical sensing platform was fabricated for the determination of acetamiprid and carbofuran. Donor-acceptor covalent organic frameworks were utilized as photoanode materials, while CuBr, with superior photochemical properties, served as the photocathode. The conjugated microporous structure of COFs accelerates photogenerated electron transfer and suppresses electron-hole recombination via the built-in electric field. The immobilized aptamer on the photoanode specifically binds with carbofuran to block electron transfer, achieving a signal-off sensing mode. Peroxymonosulfate was encapsulated in silica nanospheres, and an Act aptamer was electrostatically assembled on the surface to construct a biological gate. The specific recognition between the aptamer and acetamiprid induces PMS release, which consumes electrons and accelerates redox reactions on the photocathode to realize signal-on detection. The developed sensor exhibits low detection limits of 0.087 pg/mL for carbofuran (0.001∼100 ng/mL) and 0.065 pg/mL for acetamiprid (0.0005∼500 ng/mL). This work provides a reliable strategy for ultrasensitive dual-pesticide detection and holds promising application prospects in food safety monitoring and environmental analysis.