Bionanosphere Lithography via Hierarchical Peptide Self-Assembly of Aromatic Triphenylalanine

A nanolithographic approach based on hierarchical peptide self-assembly is presented. An aromatic peptide of N-(t-Boc)-terminated triphenylalanine is designed from a structural motif for the beta-amyloid associated with Alzheimer's disease. This peptide adopts a turnlike conformation with three phenyl rings oriented outward, which mediate intermolecular pi-pi stacking interactions and eventually facilitate highly crystalline bionanosphere assembly with both thermal and chemical stability. The self-assembled bionanospheres spontaneously pack into a hexagonal monolayer at the evaporating solvent edge, constituting evaporation-induced hierarchical self-assembly. Metal nanoparticle arrays or embossed Si nanoposts could be successfully created from the hexagonal bionanosphere array masks in conjunction with a conventional metal-evaporation or etching process. Our approach represents a bionanofabrication concept that biomolecular self-assembly is hierarchically directed to establish a straightforward nanolithography compatible with conventional device-fabrication processes.