Folding of Nanoparticle Chains into 2D Arrays: Structural Change of DNA-Functionalized Gold Nanoparticle Assemblies

Nanoparticle (NP) arrays exhibit collective physical and chemical properties, which are potentially applicable to various nanodevices, such as data storage media and biosensors. In this Communication, a spontaneous method of constructing the 2D NP arrays from precursory 1D chains of DNA-modified NPs is described. The single-stranded (ss) DNA-modified gold NPs are hybridized to a long repetitive ssDNA synthesized with rolling circle amplification to produce the precursory NP chains. Transmission electron microscopy reveals that the chains of fully matched double-stranded (ds) DNA-modified NPs undergo shrinkage and folding during evaporation to afford the 2D NP arrays. In particular, the chains of long dsDNA-modified NPs with short interparticle spacing form the NP arrays with anisotropic interparticle spacing. The present approach could be useful for readily aligning NPs on the substrate surface.