Gold nanoparticle arrays assembled on the reconstructed surface of block copolymer thin films

Abstract

Poly(styrene-block-2-vinylpyridine) (PS-b-P2VP) block copolymer thin films were used as templates for the large-area site-selective assembly of as-synthesized gold nanoparticles. The negatively-charged nanoparticles were placed on the exposed positively-charged protonated P2VP phase mainly through electrostatic interaction. Various nanoparticle arrays with different density and position selectivity were obtained rapidly and straightforwardly by controlling the assembly time. Highly ordered linear gold nanoparticle chains could be fabricated through the optimization of the assembly process. Moreover, the surface evolution of the block copolymers templates such as surface reconstruction was found to be a critical factor that significantly affects the assembly position of the nanoparticles, since the solvent from the nanoparticle solution could alter the block copolymer surface in our case. Due to the tunable plasmonic property, it is believed that these ordered nanoparticle arrays have a wide variety of potential applications in optical, sensing and SERS fields.