Mechanical manipulation assisted self-assembly to achieve defect repair and guided epitaxial growth of individual peptide nanofilaments.

We have succeeded in the production of defect-free and spatially organized individual one-dimensional peptide nanofilaments by real-time control of the self-assembly process on a solid substrate. Using a unique mechanical manipulation method based on atomic force microscopy, we are able to introduce mechanical stimuli to generate active ends at designated positions on an existing peptide nanofilament previously formed. By doing so, defects in the filament were removed, and self-repairing occurred when the active ends extended along the direction of the supporting lattice, resulting in the closure of the broken filament. Furthermore, new active ends of the nanofilaments can be specifically generated to guide the self-assembly of new filaments at designated positions with selected orientations. The mechanism of defect repair and guided epitaxial growth is also discussed.