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 K-D = 4.09 +/- 0.69 mumol L-1 and the kinetic association rate constant k(a) = 5.60 mL mumol(-1) min(-1). (C) 2004 Elsevier B.V. All rights reserved.