Sensitive detection of organophosphorus pesticides in agricultural food products by a highly luminescent coordination polymer.

Pesticide contamination in food poses a significant threat to both human well-being and ecological security. In this study, a two-dimensional Zn4 cluster coordination polymer material, {[Zn4(CAP)2(OH)2(H2O)2]·NMP·H2O} (CP 1), was synthesized and employed as a fluorescence sensor for the detection of organophosphorus pesticides, particularly methyl parathion (PAM) and parathion (PAR). Crystal structure analysis and Hirshfeld surface analysis revealed the abundance of intermolecular hydrogen bonds within CP 1, which facilitated recognition sites for selective interaction with PAM or PAR. This enabled highly selective, sensitive, efficient, anti-interference, and recyclable fluorescence detection of PAM or PAR, with detection limits as low as 2.1 nM for PAM and 2.4 nM for PAR. At the same time, the fluorescence quenching mechanism of CP 1 may be the competitive absorption and PET. CP 1 was applied to detect PAM and PAR in real agricultural samples, such as apples, cabbage, and broccoli, achieving satisfactory recovery rates ranging from 93.8 % to 102.2 % for PAM and 93.3 % to 103.4 % for PAR, respectively. These findings suggest that CP 1 holds potential as a fluorescence sensor for the practical detection of PAM and PAR in agricultural products.