Stabilized enzyme immobilization on micron-size PSt–GMA microspheres: different methods to improve the carriers' surface biocompatibility

Abstract

Stabilized immobilization of biomacromolecules on carriers with appropriate orientation and minimum conformational changes is very important in the biochemical and biomedical fields. In this study, PSt–GMA(polystyrene–glycidyl methacrylate) microspheres were utilized as the carriers of immobilizing glucose oxidase (GOD). To improve the carrier's biocompatibility, anionic sulfonate groups and different length of spacer arms were introduced onto the microspheres' surface. The effect of carrier surface properties on the activity and stability of immobilized enzymes was investigated. The results show that the introduction of sulfonate groups and spacer arms could effectively reduce the unspecific adsorption of enzymes and improve their stabilities. Besides, with the increase of the length of spacer arms, both the immobilization amount and stabilities of immobilized GOD could be increased under different experimental conditions.