A photoelectrochemical sensor based on type-II heterojunction g-C3N4/CuTCPP for voltage/light synergistic regulation of GLY adsorption/desorption

Glyphosate (GLY) is a widely used herbicide, and its potential health and environmental risks require the establishment of efficient residue detection techniques. In the design of photoelectrochemical (PEC) sensors based on CuTCPP, it is necessary to increase the visible light absorption efficiency and promote the separation of photogenerated electron-hole, as well as balance the adsorption and desorption of GLY to maintain excellent reversibility and responsiveness. In this work, the synergistic effect of type-II heterojunction g-C 3 N 4 /CuTCPP on the dynamic conversion of copper sites under illumination and applied voltage is explored for the first time and a portable glyphosate detection device is designed to meet the practical application requirements. By constructing g-C 3 N 4 /CuTCPP heterostructure, a large number of Cu + sites are generated to promote the desorption of GLY. At the same time, Cu + is oxidized by applied voltage, which promotes the adsorption of GLY and enhances the electrochemical signal response. The proposed PEC sensor exhibits a linear range from 1.0 pM to 0.1 mM and a detection limit of 0.009 pM. It can also be used to detect the GLY content in campus ponds and suburban field streams, showing satisfactory analytical performance, demonstrating the promising potential of g-C 3 N 4 /CuTCPP on the dynamic conversion of copper sites under light and applied voltage synergistically for optimizing the adsorption/desorption of GLY to boost the PEC detecting performance.