title: Modulation of the silica sol-gel composition for the promotion of direct electron transfer to encapsulated cytochrome c.
abstract: The direct electron transfer between indium-tin oxide electrodes (ITO) and cytochrome c encapsulated in different sol-gel silica networks was studied. Cyt c@silica modified electrodes were synthesized by a two-step encapsulation method mixing a phosphate buffer solution with dissolved cytochrome c and a silica sol prepared by the alcohol-free sol-gel route. These modified electrodes were characterized by cyclic voltammetry, UV-vis spectroscopy, and in situ UV-vis spectroelectrochemistry. The electrochemical response of encapsulated protein is influenced by the terminal groups of the silica pores. Cyt c does not present electrochemical response in conventional silica (hydroxyl terminated) or phenyl terminated silica. Direct electron transfer to encapsulated cytochrome c and ITO electrodes only takes place when the protein is encapsulated in methyl modified silica networks.
authors.affiliation: Dept. Química Física e Instituto Universitario de Materiales, Universidad de Alicante , Ap. 99, E-03080 Alicante, Spain.
authors.forename: Alonso
authors.initials: A
authors.lastname: Gamero-Quijano
authors.forename: Francisco
authors.initials: F
authors.lastname: Huerta
authors.forename: Emilia
authors.initials: E
authors.lastname: Morallón
authors.forename: Francisco
authors.initials: F
authors.lastname: Montilla
mesh_terms: D045304:Cytochromes c / Q000737:chemistry*; D004563:Electrochemistry; D004579:Electron Transport; D005782:Gels / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D005782:Gels; D012822:Silicon Dioxide; D045304:Cytochromes c