Study On Macromolecular Imprinting Crosslinked Polyvinylpyrrolidone Microspheres Via Suspension Polymerization

Using N-vinylpyrrolidone(NVP) as the functional monomer, N,N'-methylene- bisacrylamide (BisAM)as crosslinker, benzoyl peroxide/amine (BPO/DMA) as the redox initiator system and bovine serum albumin (BSA) as template, via suspension polymerization, we prepared protein-imprinted crosslinked polyvinyl- pyrrolidone (PVP) hydrogel microspheres and with the diameter of the microspheres being 200μm. The effects of the ratio between the continuous phase and the disperse phase, the stiring speed, the kind and quantity of the stabilizers, the polymerization temperature on the size, size distribution and morphology of the crosslinked PVP microspheres in the process of polymerization were investigated .The adsorption and recognition properties of the microspheres were studied, as well as the imprinting mechanism was discussed. The selectivity test of imprinted microspheres showed that the imprinted microspheres exhibited good recognition for BSA. The adsorption capacity of BSA-imprinted microspheres was 3.25 times more than that of non-imprinted microspheres. It was considered that the formation of multiple hydrogen bonds and complementary shape between the imprinting cavities and the template proteins were the two factors that led to the imprinting effect.The pH of BSA solution, the ionic strength, the removing methods, the initial BSA concentration and the polymerization temperature all deeply influenced the adsorption capacity and the imprinting efficiency (IE) of the BSA-IMs. Adding Na2HPO4 to BSA solution, both of the BSA-IMs and Non-IMs'equilibrium absorption capacities all increased and there was a peak value as Na2HPO4 concentration in the BSA solution got to a certain value, but the IE was gradually decreased. As the BSA solution pH increased, the equilibrium absorption capacity of the microspheres decreased gradually. With the polymerization temperature increasing both the adsorption capacity and the imprinting efficiency diminished. Both the adsorption capacity and the imprinting efficiency were lager using 10.0%HAc solution including 1.0%SDS(W/V)as the removing solution than that using 0.05mol/L Tris solution including 1.0%CaCl2.