Activity of glucose oxidase entrapped in mesoporous gels

We have immobilized a glucose oxidase (GOD) in mesoporous gels derived from tetraethoxysilane (TEOS) and organosilanes (i.e., methyltriethoxysilane (MTES), vinyltriethoxysilane (VTES), propyltriethoxysilane (PTES), and phenyltriethoxysilane (PhTES)) through a two-step sol-gel process without any templating agent. To find an optimal condition that maximizes the activity of the entrapped GOD, we investigate the effects of the organosilane precursor and the aging and drying temperature on the activity of the entrapped GOD. Our experimental results demonstrate that the activity of the entrapped GOD is highest when the gel is aged and dried at 4 °C (except for the PhTES/TEOS gels), while it is lowest when the gel is aged and dried at room temperature. We find that the use of organosilane does not significantly improve the activity of the entrapped GOD. These findings suggest a sol-gel route that can maximize the activity of the entrapped enzyme.