Immobilization of Enzymes in Sol-Gel Mesoporous Silica, Enzymatic Digestion of Biomass, and Silica-Curcumin Hybrid Materials

This research describes the immobilization of enzymes by direct encapsulation in porous silica matrix via a nonsurfactant templated sol-gel route pioneered by our group. Nonsurfactant molecules like D-fructose have been used as a template or pore forming agent, to generate silica host materials with pores in the mesoporous range (i.e., 2 to 50 nm). Our research has demonstrated that the activities of the immobilized enzymes were largely dependent on the textural properties of the silica matrix, including the specific surface area, pore volume and pore size. The immobilized enzymes exhibited up to 80% activity, compared to free native enzyme. The immobilized enzyme samples also enabled easy recovery and subsequent reusability of the enzymes. Since the spatial confinement in nanopores, the encapsulated enzymes exhibited better environmental stability. The stabilization of enzymes in high pH commercial detergent, upon encapsulation in nonsurfactant templated sol-gel silica materials, has also been exploited in this work.;In this work, we have successfully demonstrated the recyclable application of our immobilized enzyme catalyst system in biomass hydrolysis. Hydrolysis efficiencies up to 81% were obtained, and subsequent reuse exhibited negligible loss in the hydrolytic activity of our immobilized enzyme catalyst.;This research also describes the synthesis and characterization of a new class of curcumin-silica organic-inorganic hybrid materials. This work presents the preparation of the hybrid materials via covalent incorporation of the organic curcumin phase into the pre-hydrolyzed sol-gel silicate phase. The degree of incorporation of curcumin phase was verified by thermogravometric analysis (TGA). Materials characterization was done using FTIR, DSC and fluorescence spectroscopic techniques. This new class of inorganic-organic silica hybrid materials may find wide applications in implant and other biomedical materials with reduced inflammatory properties.