Fabrication of Monodisperse Core-Satellite Nanostructures by DNA-Programming: a Novel Class of Superstructured Building Blocks for Hierarchical Nanoassembly

Monodisperse nanoparticle assembly with tunable structure, composition and properties can be taken as a superstructured building block for the construction of hierarchical nanostructures from the bottom up, which also represents a great challenge in nanotechnology. Here we report on a facile and controllable method that enables a high yield fabrication of uniform gold nanoparticle (AuNP) core-satellites with definable number (in average) of the satellite particles and tunable core-to-satellite distance. The formation of the core-satellite nanostructures is driven by programmable DNA-basepairing, with the resulting nanocomplexes being isolatable via gel electrophoresis. By rationally controlling the DNA coverages on the core and shell particles, high production yields are achieved for the assembly/isolation process. As well, benefiting from a minimum DNA coverage on the satellite AuNPs, a strong affinity is observed for the as-prepared core-satellites to get adsorbed on protein-coated graphene oxide, which allows for a two-dimensional hierarchical assembly of the core-satellite structures. The resulting hierarchical nanoassemblies are expected to find applications in various areas, including plasmonics, biosensing, and nanocatalysis. The method should be generalizable to make even more complicated and higher-order structures by making use of the structural programmability of DNA molecules.