Computational design of dummy molecularly imprinted polymers via hydrogen bonding investigation for oxytetracycline determination

Oxytetracycline (OTC), a banned broad-spectrum antibiotic, currently requires highly selective and specific determination methods to measure its concentration below 200 ppb in foods of animal origin. Molecular imprinting technology could be utilized to construct a highly selective and cost-effective synthetic receptor for OTC. In this work, we investigated different monomers in designing a dummy MIP for OTC detection using TC as the dummy template. Template-monomer complexes of pre-polymerization mixtures were modeled using density functional theory for geometry optimization, intermolecular hydrogen-bonding situation, and interaction energies. O-phenylenediamine (OPD) at TC:OPD molar ratio = 1:7 was shown to be the optimum monomer, forming 11 stable intermolecular hydrogen bonds with TC and having the lowest interaction energy among the complexes. We also presented indole, pyrrole, and carbazole to be plausible monomers for imprinting TC; however, they are energetically less-favored than OPD. This study provides aid in dummy MIP design for OTC concentration measurement using the molecular level interaction of different monomers with the template TC.