The unregulated use of organophosphates (OPs) as pesticides and toxic chemical warfare agents demands their continuous monitoring from a human health perspective. This study describes a fluorescence turn-on sensing assay for the selective quantification of OPs in aqueous medium. Metal complexes of two different Biginelli derivatives were processed in water through a reprecipitation technique. The engineered self-assembly of the pyridyl-2-cobalt complex (L1路Co(II)) was employed to selectively detect malathion while the pyridyl-4-cobalt complex (L2路Co(II)) could estimate azamethiphos fluorimetrically up to a detection limit of 9.2 nM and 11 nM, respectively. Furthermore, the pesticide degradation ability of OPs was assessed using a 31P-NMR technique. This new paradigm expands the versatility of Biginelli derivatives as promising sensing platforms via metal complexation which may further be explored for estimation of analytes.
