Quercetin-imprinted monolithic polymer

Abstract

Surface molecular imprinting is a technology for producing films with imprints of molecules on the surface of carriers. It has a number of advantages in comparison with traditional molecular imprinting (bulk synthesis): an increase in the availability of molecular imprints for target molecules and a sorption capacity, as well as a cheaper sorbent material. In this work to obtain molecularly imprinted films on the surface of silica microparticles an organomineral monolithic polymer was proposed, which was prepared by a thiol-ene click reaction between glutathione and 3-methacryloxypropyltrimethoxysilane (γ-MAPS), initiated by azobisisobutyronitrile upon heating, in the presence of quercetin as a template. Samples were obtained in two methods. In the first, the surface of silica microparticles was modified with hydrolyzed γ-MAPS followed by thiol-ene click reaction in the presence of quercetin. In the second, an organomineral polymer was obtained in solution using a thiol-ene click reaction followed by acid or alkaline hydrolysis of γ-MAPS, and then the product was immobilized on the surface of silica microparticles. Samples obtained in the presence of quercetin, called as molecular imprinted (MIP), and in the absence – non-imprinted (NIP).Rebinding of quercetin was carried out under static conditions with samples after removing template. The maximum sorption capacity (8 μmol/g) were observed for samples obtained by the first method (the ratio of glutathione:quercetin 60:1), however, the imprinting factor in this case was not more than 2.0. While the samples obtained by the first and second methods (the ratio of glutathione:quercetin 6:1) showed the maximum values of the imprinting factor (2.0–3.0). Rebinding of quercetin using NIP and MIP samples obeys mainly the pseudo-first-order kinetics. Thus, the method of obtaining organomineral MIP in solution followed by immobilization on the surface of silica provides more efficient molecular imprinting than the method in which MIP is obtained on the surface of modified silica.