DNA Scaffolds for the Dictated Assembly of Left-/Right-Handed Plasmonic Au NP Helices with Programmed Chiro-Optical Properties

J Am Chem Soc. 2016 Aug 10;138(31):9895-901. doi: 10.1021/jacs.6b04096. Epub 2016 Jul 29.

Abstract

Within the broad interest of assembling chiral left- and right-handed helices of plasmonic nanoparticles (NPs), we introduce the DNA-guided organization of left- or right-handed plasmonic Au NPs on DNA scaffolds. The method involves the self-assembly of stacked 12 DNA quasi-rings interlinked by 30 staple-strands. By the functionalization of one group of staple units with programmed tether-nucleic acid strands and additional staple elements with long nucleic acid chains, acting as promoter strands, the promoter-guided assembly of barrels modified with 12 left- or right-handed tethers is achieved. The subsequent hybridization of Au NPs functionalized with single nucleic acid tethers yields left- or right-handed structures of plasmonic NPs. The plasmonic NP structures reveal CD spectra at the plasmon absorbance, and the NPs are imaged by HR-TEM. Using geometrical considerations corresponding to the left- and right-handed helices of the Au NPs, the experimental CD spectra of the plasmonic Au NPs are modeled by theoretical calculations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biosensing Techniques
  • Circular Dichroism
  • Computer Simulation
  • DNA / chemistry*
  • Gold / chemistry*
  • Metal Nanoparticles / chemistry*
  • Microscopy, Atomic Force
  • Microscopy, Electron, Transmission
  • Nucleic Acid Hybridization
  • Optics and Photonics
  • Stereoisomerism
  • Temperature

Substances

  • Gold
  • DNA