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

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• 作者：Alessandro Cecconello ; Jason S. Kahn ; Chun-Hua Lu ; Larousse Khosravi Khorashad ; Alexander O. Govorov ; Itamar Willner
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：August 10, 2016
• 年：2016
• 卷：138
• 期：31
• 页码：9895-9901
• 全文大小：503K
• 年卷期：0
• ISSN：1520-5126

文摘

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.