Direct one-step immobilization of glucose oxidase in well-ordered mesostructured silica using a nonionic fluorinated surfactant

This work describes the immobilization of glucose oxidase (GOD) in mesostructured silica. The enzyme is incorporated into the silica framework via a direct one-step immobilization method. Results obtained by SAXS and nitrogen adsorption - desorption analysis clearly show that the channel arrangement of the recovered materials depends on the GOD loading. Indeed, when the hydrothermal treatment is performed at 60 degrees C for 2 days, well-ordered materials are obtained if the GOD concentration is lower than 3.2 mg per mL of micellar solution, and higher loading leads to the formation of wormhole-like structures. The efficiency of the immobilization was revealed by fluorescence and FTIR spectroscopy. It appears that there is a maximum loading of GOD, about 11 wt %, that can be incorporated into the matrix. Results also stow that the surfactant plays the role of a pore-forming agent. Finally, we have shown that the entrapped enzyme maintains its activity.