Clustered assembly of Au nanoparticles from spherical diblock copolymer micelles encapsulating Au nanoparticle

Superstructures composed of diblock copolymer micelles and inorganic nanoparticles are quite interesting because the specific arrangement of inorganic nanoparticles within the micellar structure can reveal interesting opportunities in many field of science. In this perspective, we report a simple method to produce clustered assembly of Au nanoparticles in the micelles in attempt to induce plasmonic coupling among multiple Au nanoparticles in the assembled structures. Here, we utilized polystyrene-block-poly(acrylic acid), PS-PAA, micelles containing single Au nanoparticle in the core (Au@PS-PAA micelles) as building materials to initiate next-level assembling process. In particular, the addition of HCl to the solution of Au@PS-PAA micelles affected the overall equilibrium condition as well as kinetic process in the micellar solution. As a result, individual Au@PS-PAA micelles could be merged together to form more large micelles with inclusion of multiple nanoparticles in the core, the process of which was accompanied with plasmonic coupling of Au nanoparticles.