title: Advantages of the pre-immobilization of enzymes on porous supports for their entrapment in sol-gels.
abstract: In this work, we have compared the entrapment of free or previously immobilized glucose oxidase using a sol-gel technique. The preimmobilization was carried out on Sepabeads (a porous support) derivatized with glutaraldehyde as the functional group. The prior immobilization of the enzyme permitted to maintain the enzyme activity intact after the formation of the sol-gel. In fact, only 10% of the enzyme activity was lost whereas the soluble enzyme lost 60% of its initial activity. Additionally, enzyme leakage from the sol-gel matrix was avoided, which was relatively high when entrapping the soluble enzyme (39% of the enzyme activity was released after 16 h of incubation in a buffered solution). Moreover, the immobilized enzyme, inside the porous support, cannot be in contact with the sol-gel, and, therefore, it maintained the stability achieved by means of the multipoint covalent attachment on the Sepabeads support.
authors.affiliation: Departamento de Biocatálisis, Instituto de Catálisis, CSIC, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Betancor
authors.forename: Fernando
authors.initials: F
authors.lastname: López-Gallego
authors.forename: Aurelio
authors.initials: A
authors.lastname: Hidalgo
authors.forename: Manuel
authors.initials: M
authors.lastname: Fuentes
authors.forename: Ondrej
authors.initials: O
authors.lastname: Podrasky
authors.forename: Gabriela
authors.initials: G
authors.lastname: Kuncova
authors.forename: José M
authors.initials: JM
authors.lastname: Guisán
authors.forename: Roberto
authors.initials: R
authors.lastname: Fernández-Lafuente
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D015374:Biosensing Techniques; D004339:Drug Compounding; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D005782:Gels; D005949:Glucose Oxidase / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D005782:Gels; D005949:Glucose Oxidase