Novel monodisperse molecularly imprinted shell for estradiol based on surface imprinted hollow vinyl-SiO2 particles

A novel monodisperse molecularly imprinted shell was prepared based on surface imprinted hollow vinyl-SiO2 particles and applied to selective recognition and adsorption of estradiol (E-2). This method was carried out by introducing vinyltriethoxysilane to the surface of polystyrene (PS) spheres by a simple one-step modification, followed by dissolution to remove the PS cores, and then by copolymerization of functional monomers via surface imprinted on the hollow vinyl-SiO2 particles to prepare uniform E-2-imprinted shells. Two interesting characteristics were found: first, the obtained hollow molecularly imprinted polymer shells (H-MIPs) had highly monodispersity, uniform spherical shape with a shell thickness of about 40 nm: and then, the method was simple, easy to operate by directing coating of a uniform shell on hollow particles via surface imprinting. The resultant H-MIPs demonstrated improvements in imprinting factor and binding kinetics, owing to the high selectivity to template molecules, surface imprinting technique and hollow porous structure. Furthermore, satisfactory recoveries of 97.0 and 94.8% with respective precisions of 2.5 and 2.7% were achieved by one-step extraction when H-MIPs were used for the preconcentration and selective separation of estradiol in milk samples at two spiked levels. The simple, effective H-MIPs based strategy provided new insights into the formation of various functionalized coating layers on different kinds of support materials with versatile potential applications. (C) 2014 Elsevier BM. All rights reserved.