Plasma amino acid coatings for a conformal growth of titania nanoparticles.

We report on the conformal synthesis of ultrathin films from the amino acid histidine on flat silicon substrates and 3D periodic polymer structures via plasma enhanced chemical vapor deposition. We demonstrate the efficient utilization of this functional amino acid nanocoating for the formation of individual titania nanoparticles with dimensions from 2 to 15 nm depending upon reduction conditions. The titania nanoparticles were grown directly on histidine-functionalized planar and 3D polymer substrates by a wet-chemistry method that showed uniform surface coverage that reached approximately 75%. This approach demonstrates the potential for modifying the optical properties of periodic porous polymeric structures via direct conformal growth of titania nanoparticles.