PDA／SiO2大孔复合材料固定化荧光假单胞菌脂肪酶  

Immobilization of Pseudomonas Fluorescens Lipase on PDA/SiO_2 Macroporous Composite

作　　者：白文静[1] 李云[1] 曹大丽 吴燕飞[1] 梁云霄[1] 

机构地区：[1]新型功能材料及其制备科学国家重点实验室培育基地,宁波大学材料科学与化学工程学院,宁波315211

出　　处：《无机化学学报》2016年第11期1973-1980,共8页Chinese Journal of Inorganic Chemistry

基　　金：浙江省公益项目(No.2014C31130);浙江省自然科学基金(No.LY12B01004);宁波大学王宽诚幸福基金(No.XKL072)资助

摘　　要：以具有三维骨架结构的大孔聚合物为模板制备SiO2大孔材料，通过多巴胺在SiO2大孔材料孔道表面的原位聚合制得聚多巴胺表面功能化修饰的二氧化硅大孔材料（PDA/SiO2）。应用SEM、EDX、MIP、BET、TG—DTA和FTIR等技术对修饰前后的材料进行表征。以PDA／SiO2为载体固定荧光假单胞菌脂肪酶（PFL）．优化固定化条件并对比游离脂肪酶和固定化脂肪酶的性质。结果表明SiO2大孔材料具有三维连续贯通的孔道结构，孔径分布在300～500nm，聚多巴胺修饰后形成聚多巴胺／二氧化硅复合纳米薄膜构筑的大孔材料。在固定化时间为14h、pH值为8、初始脂肪酶浓度为0．4mg·mL-1时，固定化效果最佳，酶活回收率达246％。与游离脂肪酶相比，固定化脂肪酶有更宽的温度和pH适用范围、热稳定性显著提高，并展现出良好的储存稳定性和操作稳定性。固定化脂肪酶的Km低于游离脂肪酶的，酶与底物的亲和性较好。A large-sized macroporous SiO2 was prepared via a polymer template with three-dimensional （3D） skeletal structure and it was surface functionalized with polydopamine （PDA） by controlling the in situ polymerization of dopamine in its micro-channels to obtain the macroporous composite polydopamine/SiO2 （PDA/SiO2）. Samples were characterized by SEM, EDX, MIP, BET, TG-DTA and FTIR. PDA/SiO2 was used to immobilize pseudomonas fluorescens lipase （PFL）, immobilization conditions were optimized, and the properties of immobilized and free PFL were studied. The results show that the macroporous SiO2 has 3D continuous pass-through pore structure, the pore sizes are in the range of 300-500 nm. After modification with PDA, the pore walls of the resuiting PDA/SiO2 are composed of PDA and SiO2 composite nano-film. The best activity recovery of immobilized lipase is 246% under conditions of immobilizing time of 14 h, pH of 8 and initial PFL concentration 0.4 mg· mL-1. Compared with free PFL, the optimum working temperature and pH ranges of immobilized PFL are both widened, and the thermal stability of immobilized PFL is improved significantly. Immobilized PFL has good operational and storage stabilities. The Km of immobilized PFL is lower than that of free PFL, suggesting a better affinity capacity between PFL and substrate.

关 键 词：SiO2大孔材料 功能化修饰 聚多巴胺 固定化 荧光假单胞菌脂肪酶 

分 类 号：O814.2[理学]