Affinity parameters of amino acid derivative binding to molecularly imprinted nanospheres consisting of poly[(ethylene glycol dimethacrylate)-co-(methacrylic acid)]

The binding of l-Boc-phenylalanine anilide (BFA) and l-Boc-phenylalanine (phe) to molecularly imprinted and non-imprinted polymer nanoparticles consisting of poly[(ethylene glycol dimethacrylate)-co-(methacrylic acid)] has been investigated by adsorption experiments and mathematical modeling. The experimental isotherms have been mathematically adapted following the models of Freundlich, Langmuir, Langmuir–Freundlich, Bi-Langmuir, and extended Langmuir. The extended Langmuir model differentiated between specific and nonspecific binding of the ligand to the receptor nanoparticles and rendered excellent fitting of the experimental data. It delivered a thermodynamic and kinetic parameter set on the experimental association curves of l-BFA by l-BFA-imprinted nanospheres in suspension experiments with the equilibrium constant KD=4.09±0.69 μmol L−1 and the kinetic association rate constant ka=5.60 mL μmol−1 min−1.