(312d) Influence of Surface Functionality On Biomolecule Immobilization and Enzymatic Activity On Mesoporous Silica

Engineered surface functionality can be used to optimize the biocatalytic activity of immobilized enzymes; without the proper surface functional moiety, significant loss of enzymatic activity as well as a decline of reactant selectivity can occur. Ordered mesoporous silica materials have shown great potential as enzyme hosts and protein separation media based because properties such as pore size, pore volume and surface area can be controlled. In this study, L-tryptophan, lysozyme and bovine serum albumin are used as model biomolecules to represent a broad range of molecular weight to understand immobilization behavior. Lipase from Pseudomonas cepacia is used for immobilized enzyme activity measurement. Spherical Mesostructured Cellular Foam (MCF) silica was synthesized and characterized using nitrogen adsorption-desorption measurement to determine the pore dimensions. Two functional ligands, -(C₁₃N₂)CH₃ and -(C₁₃N₂)HN₂, which represent hydrophobic and charged groups, were grafted onto the silica surface. A comparison of the immobilization behavior and enzyme activity of the model biomolecules is used to understand how surface functionality influences protein adsorption kinetics and immobilized enzyme activity.