Designed self-assembled β-sheet peptide fibrils as templates for silica nanotubes

Sol-gel condensation of tetraethoxysilane in the presence of designed self-assembled beta-sheet peptide fibril templates, followed by template extraction, yields hollow silica nanotubes. The nanotubes are hundreds of nanometers long and possess a central pore of 3.5 nm, determined by the fibril template diameter. The effects of synthesis conditions have been investigated and the resultant silica materials characterized by various techniques. Silica nanostructures with various morphologies have been produced previously using supramolecular organic assemblies as templates. Hollow nano- or microtubes which may have applications in separations catalysis nano-optics and electronics have been of particular interest. Peptide-based templates are especially interesting because of their relevance to biological silica microstructure formation. The new fibrillar peptide templates described here have the advantages of prescribed diameter, twist pitch, and handedness, which should impart chirality on the resulting silica nanotubes, providing control of the internal surface architecture by appropriate peptide design.