Polypeptide binding to mesostructured titania films

Mesoporous titania films have been prepared via evaporation induced self-assembly and used as a matrix to bind linear pentapeptides. The mesoporous surface has been functionalized with amine groups by immersing the samples in a solution of aminopropyltriethoxysilane in toluene. Different pentapeptides have been synthesized for binding to the mesoporous films: H–Ile-Gln-Asp-Leu-Phe–COOH, H–Val-Gln-Asp-Leu-Phe–COOH and Fmoc-Phg-Gln-Asp-Leu-Phe–COOH. The peptides have been bonded to the amine functionalized surface of the titania mesoporous films with an impregnation process. The H–Val-Gln-Asp-Leu-Phe–COOH peptide has been successfully bonded to the titania matrix, while the other peptides have shown not be suitable for the process because of lower solubility and sterical hindrance. The functionalization with aminopropyltriethoxysilane and peptide binding has been studied by Fourier transform infrared spectroscopy and fluorescence spectroscopy. A fluorescent marker, fluorescein isothiocyanate, has been used to confirm the incorporation of the peptides into the titania matrix. The process is reliable and robust, after several washing cycle of the samples, the peptides are still well bonded to the titania mesoporous films.