Ligand Exchange for Controlling the Surface Chemistry and Properties of Nanoparticle Superstructures

Nanoparticle superstructures have received widespread interest due to their unique physical properties that derive from the size, shape, composition, and 3D assembly of their component nanoparticle building blocks. Successful deployment of these materials for target applications requires methods for modifying their surfaces to impart specific properties and functions. To this end, we demonstrate that ligand exchange processes, which are extensively employed for functionalizing discrete nanoparticles, can be used to modify the surfaces of nanoparticle superstructures. We show that peptides coating the external surfaces of hollow, spherical gold nanoparticle superstructures are effectively exchanged with thiolated ligands, while maintaining the integrity of the assembled structure. The resulting superstructures are stable on the bench. These proof-of-principle studies highlight the potential of using ligand exchange to differentiate nanoparticle superstructures, thereby expanding their utility and application scope.