介孔二氧化硅纳米球孔结构及其酶固定性能

Porous structure and enzyme immobilization of mesoporous silica nanospheres

采用双相合成方法,以十六烷基三甲基季铵盐为模板,以环己烷为油相试剂,制备粒径和孔结构可调的具有较大孔尺寸的介孔二氧化硅纳米球(MSNs);MSNs结构与表面物理化学性质分别通过扫描电镜、透射电镜、小角X射线衍射和氮气脱附-吸附分析仪进行表征;将MSNs通过戊二醛交联的方法用于生物大分子酶的固定,探讨孔径和孔道结构对酶固定量的影响。结果表明:MSNs的孔结构与表面活性剂中阴离子组成密切相关,制备的MSNs粒径在50~100 nm,并且随反应次数的增加而增大;介孔孔径在6.0~10.0 nm之间;酶固定量的研究发现MSNs的孔尺寸越大,孔道贯通性越好,越有利于酶固定;MSNs对葡萄糖氧化酶的固定量高达230.4 mg/g,是介孔材料SBA-15固定酶量的3倍,且固定酶的活性并没有明显的损失。

Mesoporous silica nanospheres (MSNs) with enlarged pore size have been prepared by oil-water biphasic synthesis using cetyltrimethyl ammonium salts as templates and cyclohexane as oil phase reagents. Their structural and surface physicochemical properties can be regulated by changing reaction parameters and have been characterized by scanning electron microscope (SEM),transmission electron microscope (TEM),small angle X-ray diffraction (XRD)and nitrogen desorption-adsorption analysis. The results show that the porous structure of MSNs is closely related to the anions of templates. The particle sizes of MSNs increase from 50 to 100 nm with reacting again. The pore size of the as-prepared MSNs are 6.0 ~ 9.0 nm. On the research about amount of enzymes we find that the larger pore size and the better connectivity are in favor of enzyme immobilization. The amountof enzymes immobilized on MSNs reaches 230.4 mg/g that is three times higher than that on the well-known mesoporous SBA-15. Simultaneously,the enzyme activity has no significant loss after immobilization.