EPR Studies of New Mesostructured Silica Synthesis and Hemoglobin Encapsulation

Enzyme encapsulation in ordered porous silica has been modified by introducing a natural surfactant such as lecithin during the sol-gel process. β-lactose has been used as the enzyme protecting agent and tetraethoxysilane as the source of silica in an hydroalcoholic media. In the present study, the EPR spectroscopy of paramagnetic probes has allowed to monitor the formation of mesophases and the condensation of silica in an isotropic three-dimensional structure, named Sponge Mesoporous Silica, with a pore size of 6 nm and a specific surface area of 600 m2/g. Different techniques of characterization (nitrogen sorption, XRD, TEM, SEM) have been used to study the influence of the different reactants on the structure of the materials. Hemoglobin has been encapsulated in the different materials and its catalytic pseudo peroxydase activity has been evaluated.