Synthesis of Aldehyde-Silica Nanoparticle for Matrix Immobilization of Endo-β-1,4-D-xylanase

Synthesis of silica nanoparticles has been conducted by sol gel method using Tetraethylorthosilicate (TEOS) as precursor. Silica nanoparticle was prepared by varying the molar ratio of NH3 and TEOS i.e. 0.03, 0.06 and 0.12. Mixture of TEOS, ethanol, distilled water and NH₃ as catalyst was stirred at temperature of 50 ± 2° C for 5 hours to produce sol. The sol was allowed to form gel for 48 hours. Gel of silica was kept at temperature of 70 °C to evaporate the solvent resulting in white powder of silica followed by calcination at 400°C for 8 hours. Characterization by means SEM revealed that the silica particle size was governed by the molar ratio of NH₃ and TEOS. Higher NH₃ concentration gave a bigger particle size i.e. 88.48, 271.31 and 473.52 nm respectively. Modification of the silica surface with glutaraldehyde was aimed to make the silica as immobilization matrix of endo-β-1,4-D-xylanase. Percentage of immobilized protein enzyme on silica 88.48, 271.31 and 473.52 nm were 30.49%, 15.05%, and 10.56% respectively.