摘要
A novel integrated nanobiocatalyst system based on an enzyme@silica nanoflower@metal-organic framework （enzyme@SNF@ZIF-8） structure with improved stability is fabricated for the first time. The versatility of this system is validated using penicillin G acylase （PGA） and catalase （CAT） as model enzymes. The microporous ZIF-8 layer can be controlled by varying the number of ZIF-8 coating cycles, which produces PGA@SNF@ZIF-8 nanobiocatalysts with different ZIF-8 layer thicknesses. After the second ZIF-8 coating cycle, a PGA@SNF@ZIF-8（2） structure with a homogeneous and well-intergrown ZIF-8 layer is formed, which possesses excellent mechanical and chemical stability. Moreover, PGA@SNF@ZIF-8（2） shows improved thermal/storage stability and reusability compared with free PGA and PGA immobilized on silica nanoflowers （PGA@SNF）. The obtained CAT-based nanobiocatalysts （CAT@SNF@ZIF-8（2）） also show excellent catalytic performance.
A novel integrated nanobiocatalyst system based on an enzyme@silica nanoflower@metal-organic framework （enzyme@SNF@ZIF-8） structure with improved stability is fabricated for the first time. The versatility of this system is validated using penicillin G acylase （PGA） and catalase （CAT） as model enzymes. The microporous ZIF-8 layer can be controlled by varying the number of ZIF-8 coating cycles, which produces PGA@SNF@ZIF-8 nanobiocatalysts with different ZIF-8 layer thicknesses. After the second ZIF-8 coating cycle, a PGA@SNF@ZIF-8（2） structure with a homogeneous and well-intergrown ZIF-8 layer is formed, which possesses excellent mechanical and chemical stability. Moreover, PGA@SNF@ZIF-8（2） shows improved thermal/storage stability and reusability compared with free PGA and PGA immobilized on silica nanoflowers （PGA@SNF）. The obtained CAT-based nanobiocatalysts （CAT@SNF@ZIF-8（2）） also show excellent catalytic performance.
