Industrial & Engineering Chemistry Research, Vol.53, No.10, 3854-3860, 2014
Glucose Oxidase Immobilization on Guar Gum-Gelatin Dual-Templated Silica Hybrid Xerogel
Hybrid xerogel (H5) crafted from guar gum gelatin dual-templated polymerization of tetramethoxysilane (TMOS) behaved as an effective carrier support for glucose oxidase (GOX). H5 has been characterized using Fourier transform spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), BET surface area studies, and Zeta potential and particle size distribution analysis. Under optimized conditions, H5 GOX showed a much higher bioactivity (20.73 U mg(-1)) than free GOX (9.26 U mg(-1)). The kinetic parameters of free GOX (K-M = 13.988 mg mL(-1), V-max = 1.785 mu mole mL(-1) min(-1)) and H5-GOX (K-M = 5.403 mg mL(-1), V-max = 1.75 mu mole mL(-1) min(-1)) revealed that immobilization could enhance the substrate affinity of GOX, although it did not alter the enzymatic reaction rate. H5-GOX retained similar to 96% of its initial bioactivity with 15 days of storage as a dry solid at room temperature. Recycling of H5-GOX showed only marginal loss in bioactivity up to six cycles.