Title
DNA Scaffolds for the Dictated Assembly of Left-/Right-Handed Plasmonic AuNP Helices with Programmed Chiro-Optical Properties
Author
Alessandro Cecconello, Jason S. Kahn, Chun-Hua Lu, Larousse Khosravi Khorashad, Alexander O. Govorov, Itamar Willner
Year
2016
Journal
JACS
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 twelve DNA quasi-rings interlinked by thirty 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 twelve 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.
Full Article
Instrument
J-???
Keywords
Circular dichroism, DNA structure, Nanostructures, Biochemistry, Materials