title: Internal-Modified Dithiol DNA-Directed Au Nanoassemblies: Geometrically Controlled Self-Assembly and Quantitative Surface-Enhanced Raman Scattering Properties.
abstract: In this work, a hierarchical DNA-directed self-assembly strategy to construct structure-controlled Au nanoassemblies (NAs) has been demonstrated by conjugating Au nanoparticles (NPs) with internal-modified dithiol single-strand DNA (ssDNA) (Au-B-A or A-B-Au-B-A). It is found that the dithiol-ssDNA-modified Au NPs and molecule quantity of thiol-modified ssDNA grafted to Au NPs play critical roles in the assembly of geometrically controlled Au NAs. Through matching Au-DNA self-assembly units, geometrical structures of the Au NAs can be tailored from one-dimensional (1D) to quasi-2D and 2D. Au-B-A conjugates readily give 1D and quasi-2D Au NAs while 2D Au NAs can be formed by A-B-Au-B-A building blocks. Surface-enhanced Raman scattering (SERS) measurements and 3D finite-difference time domain (3D-FDTD) calculation results indicate that the geometrically controllable Au NAs have regular and linearly "hot spots"-number-depended SERS properties. For a certain number of NPs, the number of "hot spots" and accordingly enhancement factor of Au NAs can be quantitatively evaluated, which open a new avenue for quantitative analysis based on SERS technique.
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, China.
authors.forename: Hangyong
authors.initials: H
authors.lastname: Shan
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Ye
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, China.
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Xuandi
authors.initials: X
authors.lastname: Lai
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Hu
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004587:Electrophoresis, Agar Gel; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008968:Molecular Conformation; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D014050:Toluene / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D014050:Toluene; D006046:Gold; D004247:DNA; C004848:dithiol