Preparation of porous hollow Fe3O4/P(GMA–DVB–St) microspheres and application for lipase immobilization

Functional porous hollow microspheres with superparamagnetism, Fe3O4/P(GMA–DVB–St) microspheres, were prepared via a dispersion polymerization based on hollow Fe3O4 microspheres. The resulting hollow microspheres were characterized by means of Fourier-transform infrared spectrophotometer (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) gas sorptometry, and vibrating sample magnetometer (VSM). It is verified that the resulting hollow microspheres are porous and have high saturation magnetization. For further application, candida rugosa lipase (CRL) was immobilized onto the hollow microshperes, the loading amount of lipase was 143.88 mg CRL/g support and the activity recovery of the obtained immobilized lipase reached 73.25%. Besides, the resulting immobilized CRL (ICRL) were found to have better pH endurance and temperature endurance than the free ones, which showed the optimal catalytic activity with pH of 9.0 and temperature of 60 °C. The ICRL displayed excellent reusability as well.