Epoxidation of vinyl functionalized cubic Ia3d mesoporous silica for immobilization of penicillin G acylase

Epoxy functionalized cubic Ia3d mesoporous silica (CIMS) was successfully synthesized by epoxidizing vinyl groups prepared on the CIMS by a co-condensation method. The synthesized material was characterized by X-ray diffraction, nitrogen sorption, transmission electron microscopy, thermogravimetric analysis, and solid state 13C NMR. The vinyl groups were found to be easily epoxidized to yield epoxy functionalized CIMS. The epoxy functionalized CIMS was used as a support for the immobilization of penicillin G acylase (PGA), and the effects of the epoxy group on the initial activity and the operational stability of the immobilized PGA were studied. The results showed that the enzyme loading and initial activity of the immobilized PGA decreased with increasing amounts of epoxy groups. These observations were due to a decrease in the pore size of the mesoporous silica as well as an increase in the hydrophobicity of the silica surface. However, an appropriate amount of epoxy groups on the CIMS support was found to improve the operational stability of the immobilized PGA. This improvement was the result of increased interactions between the epoxy functionalized CIMS support and the PGA.

Graphical AbstractVinyl functionalized mesoporous silica was synthesized and the vinyl groups were epoxidized to prepare epoxy functionalized mesoporous silica, which is an effective support for the immobilization of enzyme through chemical bonding.Figure optionsDownload full-size imageDownload as PowerPoint slide