Templating silica nanostructures on rationally designed self-assembled peptide fibers.

Nature presents exquisite examples of templating hard, functional inorganic materials on soft, self-assembled organic substrates. An ability to mimic and control similar processes in the laboratory would increase our understanding of fundamental science, and may lead to potential applications in the broad arena of bionanotechnology. Here we describe how self-assembled, alpha-helix-based peptide fibers of de novo design can promote and direct the deposition of silica from silicic acid solutions. The peptide substrate can be removed readily through proteolysis, or other facile means to render silica nanotubes. Furthermore, the resulting silica structures, which span the nanometer to micrometer range, can themselves be used to template the deposition of the cationic polyelectrolyte, poly-(diallyldimethylammonium chloride). Finally, the peptide-based substrates can be engineered prior to silicification to alter the morphology and mechanical properties of the resulting hybrid and tubular materials.