A novel Cu²⁺-coordinated fluorescent sensing system for specific detection of glyphosate and its applications in...

Glyphosate is a non-selective herbicide widely used in agriculture, and its overexposure poses significant health and environmental risks. Herein, a novel Cu²⁺-coordinated fluorescent sensing system (HYBC-Cu²⁺ system) based on acylhydrazone groups was designed, capable of glyphosate-specific recognition. The HYBC-Cu²⁺ system was constructed with simple steps, with the advantages of short recognition time (< 1 min), good specificity, anti-interference, and excellent sensitivity (LOD = 95 nM). The effect of proton functional group on glyphosate resulted in Cu²⁺ of the HYBC-Cu²⁺ system being able to be competed down by the glyphosate to release HYBC thus inducing the fluorescence enhancement of the system and realizing the rapid detection of glyphosate. The recognition mechanism by the HYBC-Cu²⁺ system was verified by high-resolution mass spectrometry (HRMS), density function theory (DFT) calculations and Job's Plot. The system can cycle alternately to detect the glyphosate more than 6 times and effectively quantify trace glyphosate in environmental samples. Furthermore, the HYBC-Cu²⁺ system has low cytotoxicity and good membrane permeability, which can enter HeLa cells and zebrafish to react rapidly with exogenous glyphosate, resulting in fluorescence enhancements that are visually distinctive. The application of HYBC-Cu²⁺ system can further promote the development of pesticide residue monitoring methods such as glyphosate and provide scientific basis for policy making and public health protection.