Preparation/functionalization Of Polystyrene Microspheres And Their Performance Of The Immobilized BSA

Polymer microsphere can be applied in biotechnology, biochemistry and other fields. Particularly, the application of polymer microspheres is of great attention for researchers in enzyme immobilization technology. The surface structure and properties of the polymer microspheres determines the adsorption performance of microspheres.In this paper, three types of polystyrene microsphere were prepared. Firstly is the monodisperse polystyrene microspheres that prepared by suspension polymerization. In the experimental process the amount of crosslinking agent and stirring rate were investigated, and the result show that the amount of crosslinking agent was 0.2 m L and the stirring rate was 200 rpm, the prepared microspheres show good sphericity and monodispersity. Second is P(St-co-AM) that prepared by suspension copolymerization of styrene and acrylamide. Furthermore the PS-NH2 was prepared by typically Friedel-Crafts acetylation reaction and substitution reaction on the basic of PSt microspheres. These prepared microspheres were characterized using Fourier transform infrared spectroscopy and the results prove that amide and amino ion were successfully introduced to the surface of the PSt microspheres. In order to investigate the effect of microspheres with different surface properties on the immobilization of BSA, these three kinds of microspheres were used to immobilize BSA. The results show that the presence of hydrophilic group reduces the rate of immobilized BSA. For the PS-NH2 microspheres, the immobilization rates of BSA have no obvious increase. Through optimizing the immobilized conditions such as p H and ionic strength showed that in p H 6.5 and ionic strength 20 mmol/L, the PS-NH2 microspheres have the most adsorptive property,almost reached 55 mg protein /microspheres.