Interfacial templating of inorganic nanostructures using a growth directing and reducing peptide

Abstract

The rational design of interfacially confined peptides allows for the direct examination of biomimetic processes for materials synthesis, where non-equilibrium interfacial assembly engenders complexity in metallic nano-structures. Here we report our recent progress towards applying surface-active peptides to precisely control the spatial distribution of amino acids. In order to engineer multiple length scales in inorganic materials, our periodically sequenced peptide is designed to be trifunctional: (1) self-assembling at the air–water interface, (2) reducing gold in the subphase, and (3) directing growth of the inorganic phase under confinement. We use the Langmuir trough, Brewster angle microscopy, atomic force microscopy, transmission electron microscopy and electron diffraction to characterize control over inorganic structure as a function of the surface pressure of the organic material at the interface. Single crystalline triangular nanoplatelets of gold form at a surface pressure of 30 mN m⁻¹ or less. At higher surface pressures, when binding sites are in closer proximity, a mosaic of more complex structures are formed. This work demonstrates that self-assembling surface confined peptides can be applied to define a bio-inspired tectonic process, leading to hierarchical structures at phase boundaries.