Computational Design of a Molecularly Imprinted Polymer for the Biomonitoring of the Organophosphorous Metabolite Chlorferron

Abstract

Coumaphos is an organophosphorus compound used as insecticide and frequently used by beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN), has been identified in biological samples and foodstuff. The need to quickly identify the presence of typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption-controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained median % recovery was around 98%. The results were also validated to reference values obtained using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the usability of the method in biological samples, showing the potential for biomonitoring. The developed imprinted sensor showed maximum signal change less than 16.8% when related metabolites or pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules. The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers similar LoDs than chromatographic methods with shorter analysis time.

Chitosan-Based Molecularly Imprinted Polymers for Effective Trapping of the Nerve Agent Simulant Dimethyl Methylphosphonate

“…To optimize the affinity and imprinting efficiency of the MIP, it is crucial that an appropriate template-to-functional monomer ratio is selected. Oversaturating the mixture with excess monomer or template can affect the binding energy of the complex and decrease the number of cavities created in the polymer matrix. , Therefore, the ratio between DMMP and chitosan was investigated using a computational method previously developed in another paper by Qader et al…”

“…Computational calculations were carried out using density functional theory (DFT) with the B3LYP/6-31G level to calculate the electronic binding energies . The energies for the template ( E template ), monomer ( E mon ), and template–monomer complex ( E Cplx ) were then used to calculate the residual binding energy of the template-monomer complex using eq 1.…”

“…Oversaturating the mixture with excess monomer or template can affect the binding energy of the complex and decrease the number of cavities created in the polymer matrix. 32,33 Therefore, the ratio between DMMP and chitosan was investigated using a computational method previously developed in another paper by Qader et al 34 Computational calculations were carried out using density functional theory (DFT) with the B3LYP/6-31G level to calculate the electronic binding energies. 34 The energies for the template (E template ), monomer (E mon ), and template−monomer complex (E Cplx ) were then used to calculate the residual binding energy of the template-monomer complex using eq 1.…”

“…32,33 Therefore, the ratio between DMMP and chitosan was investigated using a computational method previously developed in another paper by Qader et al 34 Computational calculations were carried out using density functional theory (DFT) with the B3LYP/6-31G level to calculate the electronic binding energies. 34 The energies for the template (E template ), monomer (E mon ), and template−monomer complex (E Cplx ) were then used to calculate the residual binding energy of the template-monomer complex using eq 1. The 1:3 ratio of DMMP to chitosan was selected as it produced the most negative value (shown in Table S1), which will theoretically produce the most energetically stable template−monomer complex.…”

Simple and Fast Pesticide Nanosensors: Example of Surface Plasmon Resonance Coumaphos Nanosensor

“…Coumaphos is an organophosphorus compound used as an insecticide frequently by beekeepers to manage parasitic mites [9]. Even though pesticides such as coumaphos are used to protect bee colonies against mite infestation, it poses a risk for bees and humans [10,11].…”