Hydrazide-modified diformylphenol fluorescent sensor-metal complexes for rapid and sensitive detection of glyphosate...

Organophosphorus (OP) pesticides are extensively used in modern agriculture; however, their widespread application and persistence in the environment raise significant concerns due to their toxicity effects on human health and ecosystems. Therefore, the development of sensitive, selective, and cost-effective methods for OP pesticide monitoring remains highly desirable. In this study, two novel diformyl phenol-based fluorescent sensors containing thiophene and furan heterocyclic units were synthesized and structurally characterized by ¹H/¹³C NMR, FT-IR, and mass spectrometry analyses. The metal-ion recognition properties of the sensors were subsequently investigated, revealing selective interactions with Cu²⁺ and Zn²⁺ ions and leading to the formation of the corresponding sensor-metal complexes. The sensing performance of these platforms was evaluated toward several OP pesticides, including fosetyl-Al, dimethoate, glufosinate, malathion, glyphosate, phosmet, and fenamiphos. Under optimized experimental conditions, all sensor-metal systems exhibited measurable fluorescence responses, with the highest sensitivity observed for glyphosate. Following the optimization of experimental parameters, including pH and solvent composition, the analytical performance of the developed sensing platforms was systematically assessed in terms of linear dynamic range, limit of detection (LOD). In addition, selectivity studies conducted in the presence of potentially interfering environmental species demonstrated the excellent discrimination capability of the proposed sensor-metal systems. Finally, successful determination of glyphosate in real samples confirmed the applicability of these sensor-metal platforms as reliable and highly sensitive analytical tools for environmental monitoring and pesticide analysis.