氨基化树枝状介孔二氧化硅固定葡萄糖氧化酶用于检测葡萄糖

以三乙胺为碱源合成了树枝状介孔二氧化硅纳米粒子(DMSNs),并用3-氨基丙基三乙氧基硅烷(APTES)进行氨基修饰合成了氨基化树枝状介孔二氧化硅纳米粒子(DMSNs-NH₂),将其用于葡萄糖氧化酶(GOD)的固定化研究.采用扫描电子显微镜、透射电子显微镜、红外光谱仪、X射线衍射仪、氮气吸附仪及热重分析仪对固定化GOD(DMSNs-NH₂-GOD)进行了表征,测定了其活性及蛋白载量.结果表明,固定化GOD的直径约为200 nm,形状均一,呈分散的球形微粒;在最佳固定条件下,蛋白载量达225 mg/g,酶活性达215 U/mg;固定化GOD检测葡萄糖的最低检测限为0.0014 mg/mL.利用固定化GOD检测了血清和饮料中的葡萄糖,重复使用36次以上其相对酶活性仍剩余80%.该方法操作方便、准确度高,提高了酶的pH稳定性、热稳定性及重复使用性,降低了检测成本.

Glucose Oxidase Immobilization with Amino Dendritic Mesoporous Silica Nanoparticles and Its Application in Glucose Detection

Dendritic mesoporous silica nanoparticles(DMSNs) were synthesized with triethylamine as template and modified with 3-aminopropyl triethoxylsilane(APTES). Glucose oxidase(GOD) was immobilized by a Amino dendritic mesoporous silica nanoparticles(DMSNs-NH₂). The immobilized glucose oxidase(DMSNs-NH₂-GOD) was characterized by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, nitrogen adsorption apparatus and thermogravimetry. The activity and protein loading of immobilized glucose oxidase were determined. The results showed that the diameter of immobilized GOD was about 200 nm, the shape was uniform, and immobilized GOD was dispersed as spherical particles. Under the optimal fixation conditions, the protein loading reached 225 mg/g and the enzyme activity reached 215 U/mg. The minimum detection limit for glucose detection by immobilized GOD is 0.0014 mg/mL. Immobilized GOD was used to detect glucose in serum and beverage, which could be reused for more than 36 times, with the relative enzyme activity remaining 80%. The method is easy to operate and accurate. In the same time, it improves the pH stability, thermal stability, reusability of the enzyme and reduces the cost.