Assembly of polygonal nanoparticle clusters directed by reversible noncovalent bonding interactions

The reversible molecular template-directed self-assembly of gold nanoparticles (AuNPs), a process which relies solely on noncovalent bonding interactions, has been demonstrated by high-resolution transmission electron microscopy (HR-TEM). By employing a well-known host−guest binding motif, the AuNPs have been systemized into discrete dimers, trimers, and tetramers. These nanoparticulate twins, triplets, and quadruplets, which can be disassembled and reassembled either chemically or electrochemically, can be coalesced into larger, permanent polygonal structures by thermal treatment using a focused HR-TEM electron beam.