Preparation And Performance Of Bsa Molecularly Imprinted Polymer With A Core-shell Structure And Magnetic Susceptibity

Molecular imprinting technique (MIT) is a synthetic approach for the preparation of molecular imprinted polymers (MIPs) in which a three-dimensional polymeric matrix around a template molecule is created. After the template molecule is removed by physical and chemical methods, complementary cavities with respect to shape and functional groups remain in the polymeric matrix. MIPs have been produced for the applications in in vitro diagnostics, therapeutics and separations. Recently, macromolecular imprinting technique becomes the hot research areas, such as protein. Imprinting of protein confronts many difficulties, such as the higher molecular weight values and the bigger volume in space, which lead to the slow rate of mass transfer. Up to now, it is still a challenge for the effective molecular imprinting of protein.In this paper, a sol-gel method was first used to prepare Fe₃O₄@SiO₂ microspheres with the Fe₃O₄ core and SiO₂ shell. At room temperature, Fe₃O₄@SiO₂ microspheres have both superparamagnetic and biocompatibile characteristics. An orthogonal design experiment L16(45) was performed to investigate the effect on the size and morphology exerted by different conditions, such as ammonia aqueous, TEOS, alcohol, the VE/W and the concentration of magnetic liquid. It is determined that the type of alcohol is the key factor. At room temperature, the magnetic saturation strength of Fe₃O₄ and Fe₃O₄@SiO₂ microspheres are 73.839 emu/g and 33.162 emu/g, respectively.Bovine Serum Albumin (BSA) was chosen as the template molecule on the supporting material of Fe₃O₄@SiO₂ microspheres. MIPs were prepared by the surface imprinting method. The rests reveal that the as-prepared MIPs complex is characteristics with the double shell structure - the core of Fe₃O₄-coated SiO₂ layer and the shell of MIPs layer. The test of thermodynamics absorption experiments proved that Fe₃O₄@SiO₂-MIPs have strong affinity to BSA. The absorption rule of MIPs follows the Langmuir isothermal adsorption equation. Furthermore, the effect on absorption capacity of MIPs by the size of Fe₃O₄@SiO₂ microspheres was carried out. The test results show that the MIPs obtained by Fe₃O₄@SiO₂ microspheres in 390 nm have the largest absorption quality.