Synthesis, characterization and application of core–shell magnetic molecularly imprinted polymers for selective recognition of clozapine from human serum

Abstract

In this article, a magnetic molecularly imprinted polymer (MMIPs) based on Fe₃O₄@SiO₂ has been synthesized for simply extraction of clozapine (CLZ) from human serum. The MIPs were coated on the Fe₃O₄@SiO₂–NH₂ surface by the copolymerization of methacrylic acid with ethylene glycol dimethacrylate; and clozapine as a template molecule. The properties of the obtained Fe₃O₄@SiO₂–MIPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, dynamic light scattering, energy dispersive X-ray analysis (EDX), a vibration sample magnetometer and rebinding experiments. The Fe₃O₄@SiO₂–MIPs showed a highly improved imprinting capacity, a fast adsorption equilibrium, and significant selectivity in molecularly imprinted solid-phase extraction of CLZ from human serum. In addition, MMIPs were regenerated and their adsorption capacity in the eighth use showed about an 6.67% loss in clozapine solution. Also, the intra and inter-day precision values were less than 6 and 4%, respectively. These results suggest Fe₃O₄@SiO₂–MIPs may be used for selective extraction and analysis of CLZ in human serum.