Adsorption and selective recognition of 17ß-estradiol by molecularly imprinted polymers

Abstract

The 17s-estradiol-imprinted polymers using non-covalent approach with methacrylic acid as the functional monomer was prepared and characterized. The effect of porogenic solvents on the adsorption capacity and thermal stability of the molecularly imprinted polymers (MIPs) were examined. Scanning electron microscopic images showed that the synthesized MIPs were bulk porous materials. The surface areas of MIPs increased from 151–188 to 239–292 m2 g-1 when templates were removed by methanol using Soxhlet extraction. In addition, the MIPs prepared in chloroform had a higher adsorption capacity towards 17s-estradiol (1,212 μg g-1) than that in acetonitrile (769 μg g-1), indicating that less polar porogenic solvent is suitable for synthesis of non-covalent MIPs. FTIR showed that the carbonyl group is the major functional group in MIPs to form monomer-template complex via H-bond. In addition, only a slight decrease ( testosterone > benzo[a]pyrene > progesterone > phenol, and the κimp’ values decreased from 2.68 to 0.63, indicating the excellent selectivity of MIPs among closely related compounds. Results obtained in this study clearly indicate that the imprinted polymer is specific for recognizing 17s-estradiol. The excellent selectivity and high adsorption capacity of 17s-estradiol-imprinted polymers open the door to develop MIPs for effective separation and adsorption of estrogenic compounds.