Self-powered photoelectrochemical platform with Cs3BiBr6/AgInS2 photoanode and CuBi2O4 photocathode for ultrasensitive glyphosate analysis in food samples

A self-powered PEC sensor was developed for sensitivity glyphosate detection. • Cs 3 BiBr 6 -AgInS 2 was used as photoanode to provide photo electrons transmission. • CuBi 2 O 4 used as photocathode for providing electric energy for target detection. • The proposed glyphosate sensor showed a wide linear range of 1 × 10 −10 - 5 × 10 −4  mol/L. A self-powered photoelectrochemical (PEC) sensor was developed for the ultrasensitive and rapid detection of glyphosate, a widely used herbicide and potential contaminant in fruits and vegetables. The sensor integrates a Cs 3 BiBr 6 /AgInS 2 composite photoanode with a CuBi 2 O 4 -based photocathode. As a lead-free halide perovskite, Cs 3 BiBr 6 exhibits broad light absorption and prolonged carrier lifetime, while AgInS 2 modification markedly enhances the photoelectric conversion efficiency and optical stability of the photoanode. Meanwhile, CuBi 2 O 4 possesses excellent biocompatibility and abundant active sites, enabling efficient aptamer immobilization for the selective recognition of glyphosate. Under optimized conditions, the photocurrent response decreased linearly with increasing glyphosate concentrations over the range of 1.0 × 10 −10 –5.0 × 10 −4  mol/L, with a low limit of detection (LOD) of 4.6 × 10 −11  mol/L. In addition, the proposed PEC sensor demonstrated excellent stability, reproducibility, and accuracy in the analysis of real food samples, including soybean and corn, highlighting its considerable potential as a reliable analytical platform for on-site monitoring of pesticide residues in agricultural products. Download: Download high-res image (144KB) Download: Download full-size image