Controlled patterning of aligned self-assembled peptide nanotubes

Controlling the spatial organization of objects at the nanoscale is a key challenge in enabling their technological application^1–3. Biomolecular assemblies are attractive nanostructures owing to their biocompatibility, straightforward chemical modifiability, inherent molecular recognition properties and their availability for bottom-up fabrication^4–16. Aromatic peptide nanotubes are self-assembled nanostructures with unique physical and chemical stability and remarkable mechanical rigidity^14–16. Their application in the fabrication of metallic nanowires and in the improvement of the sensitivity of electrochemical biosensors have already been demonstrated^14–17. Here we show the formation of a vertically aligned nanoforest by axial unidirectional growth of a dense array of these peptide tubes. We also achieved horizontal alignment of the tubes through noncovalent coating of the tubes with a ferrofluid and the application of an external magnetic field. Taken together, our results demonstrate the ability to form a two-dimensional dense array of nanotube assemblies with either vertical or horizontal patterns.