title: Protein Adsorption on Nanocrystalline TiO(2) Films:  An Immobilization Strategy for Bioanalytical Devices.
abstract: We have investigated the use of optically transparent, nanoporous TiO(2) films as substrates for protein immobilization. Immobilization on such films may be readily achieved from aqueous solutions at 4 °C. The nanoporous structure of the film greatly enhances the active surface area available for protein binding (by a factor of 150 for a 4-μm-thick film). We demonstrate that the redox state of immobilized cytochrome c may be modulated by the application of an electrical bias potential to the TiO(2) film and that the fluorescence yield of immobilized fluorophore-labeled maltose-binding protein may be used to monitor specifically maltose concentration. We conclude that nanoporous TiO(2) films may be useful both for basic studies of protein/electrode interactions and for the development of array-based bioanalytical devices employing both optical and electrochemical signal transduction methodologies.
authors.affiliation: Department of Biochemistry, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2AY, U.K.
authors.forename: E
authors.initials: E
authors.lastname: Topoglidis
authors.forename: A E
authors.initials: AE
authors.lastname: Cass
authors.forename: G
authors.initials: G
authors.lastname: Gilardi
authors.forename: S
authors.initials: S
authors.lastname: Sadeghi
authors.forename: N
authors.initials: N
authors.lastname: Beaumont
authors.forename: J R
authors.initials: JR
authors.lastname: Durrant