Protein Adsorption on Nanocrystalline TiO↓(2) Films: An Immobilization Strategy for Bioanalytical Devices

摘要

We have investigated the use of optically transparent, nanoporous TiO↓(2) films as substrates for protein im-mobilization. Immobilization on such films maybe 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 a4-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 ad that the fluorescence yield of immobilized fluoro-phore-labeled maltose-binding protein may be used to realtor 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.