1D to 2D Self Assembly of Cyclic Peptides

Despite recent developments in two-dimensional self-assembly,
most
supramolecular 2D materials are assembled by tedious methodologies,
with complex surface chemistry and small sizes. We here report d/l-alternating cyclic peptides that undergo one-dimensional
self-assembly into amphiphilic nanotubes, which subsequently arrange
as tubular bilayers to form giant nanosheets in the mesoscale. Reversible
transitions between the assembled, dispersed, and aggregated states
of these nanosheets can be triggered by external stimuli. The characteristic
flexibility, defined chemical topology, and length scale of these
nanosheets set a clear distinction between this new supramolecular
architecture and previously reported 2D nanostructures. The sequential
1D-to-2D self-assembly of peptides described here provides a conceptually
new approach to achieve two-dimensional materials with hierarchical
organization. These giant nanosheets represent one of the largest
2D supramolecular materials ever made, with potential application
as long-range molecular transporters, responsive surfaces, and (bio)­sensors.