Preparation and characterization of molecular imprinted polymer functionalized with core/shell magnetic particles (Fe3O4@SiO2@MIP) for the simultaneous recognition and enrichment of four taxoids in Taxus x media

In this work, the superparamagnetic Fe3O4 particles prepared by the coprecipitation method were coated successively by SiO2, vinyl end groups and molecularly imprinted polymer (MIP) shells to afford a pomegranate-like core/shell superparamagnetic particle (Fe3O4@SiO2@MIP), and the MIP shell preparation conditions were optimized by multi-objective response surface methodology. In order to simultaneously enrich and separate the four taxoids (10-DAB, baccatin III, cephalomannine and paclitaxel), cephalomannine was selected as the template because of its similar chemical structure to other three taxoids and relative inexpensiveness. Especially, to avoid template leaking which may influence the accuracy of identification and quantitation of the analytes, we selected paclitaxel as the target molecular during the investigation of the adsorption property of Fe3O4@SiO2@MIP particles. This strategy was similar to the dummy molecular imprinting technique in which the dummy molecularly imprinted polymer was prepared by using a dummy template, structural analog of the target analyte. The as-prepared Fe3O4@SiO2@MIP particles were characterized by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR). The adsorption kinetics, isotherms and reusability were also investigated. Finally, the Fe3O4@SiO2@MIP particles were successfully applied to simultaneously enrich and separate these four taxoids in the extract of Taxus x media (T. x media). (C) 2015 Elsevier B.V. All rights reserved.