title: DNA-directed gold nanodimers with tunable sizes and interparticle distances and their surface plasmonic properties.
abstract: A quantitative understanding of the localized surface plasmon resonances (LSPRs) of metallic nanostructures has received tremendous interest. However, most of the current studies are concentrated on theoretical calculation due to the difficulty in experimentally obtaining monodisperse discrete metallic nanostructures with high purity. In this work, endeavors to assemble symmetric and asymmetric gold nanoparticle (AuNP) dimer structures with exceptional purity are reported using a DNA self-assembly strategy through a one-step gel electrophoresis, which greatly facilitates the preparation process and improves the final purity. In the obtained Au nanodimers, the sizes of AuNPs (13, 20, and 40 nm) and the interparticle distances (5, 10, and 15 nm) are tunable. The size- and distance-dependent plasmon coupling of ensembles of single, isolated dimers in solution are subsequently investigated. The experimental measurements are correlated with the modeled plasmon optical properties of Au nanodimers, showing an expected resonance shift with changing particle sizes and interparticle distances. This new strategy of constructing monodisperse metallic nanodimers will be helpful for building more complicated nanostructures, and our theoretical and experimental understanding of the intrinsic dependence of plasmon property of metallic nanodimer on the sizes and interparticle distances will benefit the future investigation and exploitation of near-field plasmonic properties.
authors: Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
authors: Xiang
authors: X
authors: Lan
authors: Zhong
authors: Z
authors: Chen
authors: Bi-Ju
authors: BJ
authors: Liu
authors: Bin
authors: B
authors: Ren
authors: Joel
authors: J
authors: Henzie
authors: Qiangbin
authors: Q
authors: Wang
mesh_terms: D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D004586:Electrophoresis; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold; D004247:DNA
keywords: DNA self-assembly; dimer nanostructures; gold nanoparticles; surface plasmon resonances