A SiO₂ Microcarrier with an Opal-like Structure for Cross-Linked Enzyme Immobilization

Abstract

The opal-like SiO 2 microcarriers with different pore diameters named opal-SiO 2 I and opal-SiO 2 II were synthesized and utilized as microcarriers to immobilize Rhizopus oryzae lipase (ROL) and Aspergillus oryzae α-amylases (AOA). ROL and AOA can be more stably immobilized on the cross-linked SiO 2 opals by neopentyl glycol diglycidyl ether (NGDE), which is the first attempt to use it as a cross-linking agent compared with glutaraldehyde. According to the morphology analysis, multiple layers of SiO 2 monodisperse microspheres were regularly packed and formed an opal-like structure, and enzymes were well scattered and immobilized throughout the SiO 2 opals. The results showed that the performance of enzymes immobilized on opal-SiO 2 II with a larger specific surface area was much better than that of opal-SiO 2 I.

Multipoint Immobilization at the Inert Center of Urease on Homofunctional Diazo-Activated Silica Gel: A Way of Restoring Room-Temperature Catalytic Sustainability for Perennial Utilization

“…Immobilized enzymes dispersed on the porous support surface achieved stabilization for different reasons, stated as follows. Immobilized enzymes get hold of a favorable enzyme environment in porous media, , are recycled over a prolonged period after its separation from the reaction medium, and do not suffer from intermolecular-inactivation processes, which appear either for precipitation or for proteolysis or interaction with external hydrophobic interfaces. , Second, increasing the enzyme rigidity via multipoint covalent attachment ,,,,− prevents the subunit dissociation of multimeric proteins ,, that stabilize immobilized enzymes compared to their native form.…”

Biocatalytic System Made of 3D Chitin, Silica Nanopowder and Horseradish Peroxidase for the Removal of 17α-Ethinylestradiol: Determination of Process Efficiency and Degradation Mechanism

“…One of the most interesting supports for enzyme immobilization is SiO 2 . This inexpensive material, due to its properties such as lack of toxicity, great chemical activity and high porosity as well as the presence of hydroxyl groups onto its surface [17,18], has been widely used for attachment of various enzymes. As was presented by Mondal et al [19], urease immobilized by covalent binding onto a 3D silica gel, retained 100% of its catalytic activity after 30 days, whereas Libertino et al [20] showed that glucose oxidase immobilized onto porous SiO 2 was able to retain its activity even after 3 months of storage.…”

Engineering Mussel-Inspired Coating on Membranes for Green Enzyme Immobilization and Hyperstable Reuse

“…Various chemical reagents can be applied for carrier modification, such as glutaraldehyde (GA), genipin, glycidol, polyaldehydes, epichlorohydrin, citric acid, sodium tripoly­phosphate (TPP), glyoxal, 1-ethyl-3-(3-(dimethyl­amino)­propyl)­carbo­diimide/ N -hydroxy­succinimide (EDC/NHS), and ethylene­diamine (EDA) . However, these chemical reagents would cause environmental issues and health risks . To address these problems, a green carrier modification strategy is imperative.…”

“…8 However, these chemical reagents would cause environmental issues and health risks. 9 To address these problems, a green carrier modification strategy is imperative. Mussel-inspired coating is a green and facile carrier modification strategy for covalent enzyme immobilization.…”