Immobilization of Laccase in Glycidoxypropyl-Functionaiized Magnetic Mesoporous SiO_2/Fe_3O_4 Hollow Microspheres

摘要

Glycidoxypropyl-functionalized magnetic mesoporous SiO_2/Fe_3O_4 hollow microspheres (FMMS) with various amounts of terminally bonded groups in the pore channels were synthesized by the co-condensation of tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxylsilane (GPTMS) in the presence of cetyltrimethylammonium bromide and 1,3,5-triisoporpylbenzene, and utilized as supports for laccase immobilization. It is revealed that glycidoxypropyl groups have been covalently attached to the pore wall of magnetic mesoporous SiO_2/Fe_3O_4 hollow microspheres (MMS). The magnetic mesoporous SiO_2/Fe_3O_4 microspheres (sample 10% FMMS) have a saturation magnetization of 13.6 emu-g"1 and a low coercivity (50 Oe). The functional materials preserve a mesoscopic ordering at a concentration of GPTMS as high as 15%. The BET surface area and pore volume of the functionalized materials decrease with increasing amount of GPTMS, but a desirable pore structure remains when the GPTMS amount increases to 10%. The 10% FMMS material exhibits higher laccase immobilization and stability than pure MMS because of the covalent interaction between the amino groups of laccase and the epoxy groups of the functional MMS.