Preparation and characterization of mesoporous materials from a nonionic fluorinated surfactant: Adsorption of glucose oxidase

Abstract

In this work, mesostructured silica materials prepared by using a nonionic fluorinated surfactant-based system have been used as supports for the adsorption of glucose oxidase (GOD). Prior to the enzyme adsorption, we have characterized in detail the mesoporous material and we have evidenced that the structural and textural properties of the matrix are not affected by the treatment in water at room temperature. Due to its large size, GOD is not immobilized within the mesopore but on the surface. However, the FTIR analysis shows that GOD strongly interacts with the matrix. Indeed, the vibration due to the free silanol groups (3741 cm −1) progressively vanished with the increase in the GOD loading. This also shows that interactions between GOD and silica occur through hydrogen bonds between NH or C O groups of the enzyme and the surface silanol groups of the mesostructure. The quantity of adsorbed enzyme has been determined by solid state UV spectroscopy. A colorimetric method was also used to test GOD activity. Our results show that the activity of the GOD immobilized on the mesoporous material is higher than the one of GOD immobilized on a non-templated silica support.