Yanchun Liao, Yiping Feng, Zhu Wang
Organophosphorus pesticides (OPPs) pose severe environmental and human health risks owing to their inherent persistence, slow spontaneous hydrolysis, and strong inhibitory activity against acetylcholinesterase. However, conventional remediation approaches for OPPs suffer from low neutral-condition efficiency, poor reaction selectivity, and limited practical environmental applicability. Herein, a self-supported Mn-doped Cu-C-N-based coordination polymer (CuMn@CN) with tailored Cu+ active sites using ligand anchoring was fabricated for the efficient hydrolysis of representative OPPs and colorimetric detection of methyl parathion (MP) under environmentally relevant neutral conditions. Structural characterization confirms the uniform dispersion of Cu and Mn sites within the C-N framework, which constructs stable metal-N and metal-O coordination configurations and mixed-valence active centers. Under neutral conditions, CuMn@CN exhibits prominent hydrolytic performance toward typical OPPs (e.g., methyl parathion and chlorpyrifos) and complies with typical Michaelis-Menten kinetics with a low KM value of 0.04675 - 0.6313 mM, indicative of excellent substrate affinity. Meanwhile, the catalyst exhibits robust durability and environmental adaptability in complex systems containing coexisting inorganic anions and real water matrices, as well as during cyclic catalytic operations. With the in-situ generation of 4-nitrophenol, a sensitive colorimetric sensing platform was established, achieving quantitative MP detection over a wide linear range of 0.1 - 200.0 μmol L-1 and facilitating rapid visual screening of MP in water samples without reliance on sophisticated instrumentation. Integrated experimental results and DFT/Fukui function analyses reveal a unique Lewis acid-assisted hydrolysis mechanism, where the synergistic effects of bimetallic sites enable substrate adsorption, P-O bond polarization, and nucleophilic attack by surface-activated H2O/metal-OH species.