Catalytic Activity in Organic Solvents and Stability of Immobilized Enzymes Depend on the Pore Size and Surface Characteristics of Mesoporous Silica

TLDR: In this paper, an enzyme, horseradish peroxidase (HRP), was adsorbed in the manner of the single immersion method on the silica mesoporous materials FSM-16, MCM-41, and SBA-15 with various pore diameters from 27 to 92 A, and their enzymatic activities in an organic solvent and thermal stabilities were studied.

Abstract: An enzyme, horseradish peroxidase (HRP), was adsorbed in the manner of the single immersion method on the silica mesoporous materials FSM-16, MCM-41, and SBA-15 with various pore diameters from 27 to 92 A, and their enzymatic activities in an organic solvent and the thermal stabilities were studied. FSM-16 and MCM-41 showed a larger amount of adsorption of HRP than SBA-15 or silica gel when the pore sizes were larger than the 50 A. The increased enzyme adsorption capacity may be due to the surface characteristics of FSM-16 and MCM-41, which would be consistent with the observed larger adsorption capacity of cationic pigment compared with anionic pigment for these materials. The immobilized HRP on FSM-16 and MCM-41 with pore diameter 50 A showed the highest enzymatic activity in an organic toluene and thermal stability in aqueous solution at the temperature of 70 °C. The immobilized enzymes on the other mesoporous materials including large or small pore sized FSM-16 showed lower enzymatic activity in an or...