Self-assembly of gold nanoparticles into ring-like hierarchical superstructures with tunable interparticle distance.

Ring-like hierarchical superstructures have attracted increasing attention in recent years due to their structural symmetry and interesting properties. Here, we obtain well-defined ring-like superstructures with tunable interparticle distance from the self-assembly of polystyrene (PS)-tethered gold nanoparticles (AuNPs@PS). The results show that the interparticle distance between the adjacent AuNPs of the ring-like superstructures can be systematically tailored by adjusting the molecular weight of the tethered PS ligands. The thickness of the ring-like superstructures is proportional to the concentration of the inorganic NP building blocks. Interestingly, the formation of ring-like superstructures can be extended to a variety of inorganic NP building blocks with different diameters, shapes, tethered polymers. The PS-tethered gold nanorods (AuNRs) and gold nanocubes (AuNCs) can also self-assemble into ring-like superstructures. It is noteworthy that this strategy is universal to fabricate a variety of ring-like superstructures, which have potential applications in surface-enhanced Raman scattering, optoelectronics, and sensors.