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

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 Å, 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 Å. 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 Å 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 organic solvent and thermal stability. Both surface character and size matching between pore sizes and the molecular diameters of HRP were important in achieving high enzymatic activity in organic solvent and high thermal stability.

Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation

“…HRP takes about 40 min, Cyt c takes 30 min, while MP-11 takes about 10 min. However, for mesoporous silica, saturated enzyme loading usually takes at least several days to reach [28][29][30] . After the loading of enzymes, the crystallinity, porosity and thermal stability of PCN-333(Al) samples were characterized, showing well-maintained framework (Supplementary Figs 40-54).…”

Graphene and graphene oxide as nanomaterials for medicine and biology application

“…Introduction of various metals such as Au, Ag, Pd and Pt with the graphene nanosheet has been reported [47]. The immobilization of enzymes on inorganic materials has proved to be a fruitful application, improving its stability under various conditions [48]. Nanomaterials such as magnetic GO are synthesized by covalent binding of amino Fe 3 O 4 onto GO and were used to immobilize laccase [49].…”

Electrochemical Impedance Study of Screen-printed Branch Structure Porous Carbon Electrode using MgO-templated Carbon and MgO Particle and its Application for Bilirubin Oxidase-immobilized Biocathode

“…In addition, the stability of the enzyme may be improved. [8][9][10][11][12] In the present study, we focus on MgOtemplated mesoporous carbon (MgOC) with an average pore diameter of 38 nm and a narrow size pore size distribution because the pore size is easy to control. 13 Furthermore, to effectively supply oxygen to enzymes immobilized in the mesopore, we newly prepared a branch structure porous carbon electrode consisting of macropores and mesopores ( Fig.…”