title: Optically Active AuNR@Ag Core-Shell Nanoparticles and Hierarchical Assembly via DNA-Mediated Surface Chemistry.
abstract: To manipulate the chiroptical activity of plasmonic metal nanoparticles (MNPs) and control their hierarchical self-assembly are of great fundamental and technological significance; however, they remain a big challenge. Here, we in situ fabricated anisotropic bimetallic AuNR@Ag core-shell nanoparticles (AuNR@Ag NPs) capped with designed DNA molecules and systematically studied the plasmonic chiroptical properties of the individual AuNR@Ag NPs and their assemblies. The AuNR@Ag NPs were facilely prepared by employing DNA-capped Au nanorods (AuNRs) as seeds to grow Ag shells, and it was found that the as-prepared AuNR@Ag NP surfaces were encoded by the original DNA molecules through an in situ DNA "desorption and re-adsorption" dynamic process during shell overgrowth. This observation is distinctly different from the previous results that DNA molecules were embedded in the Ag shell. Interestingly, with this in situ DNA-mediated surface chemistry, plasmonic chiroptical activities were observed from individual AuNR@Ag NPs, and the chiroptical responses were conveniently manipulated over a broad optical window by simply modifying the shape anisotropy of the building blocks. Furthermore, the DNA molecules capped on the AuNR@Ag NP surface facilitate the hierarchical assembly of homogeneous and heterogeneous nanostructures with distinct chiral optical responses.
authors.affiliation: CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Lan
authors.affiliation: CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123, China.
authors.forename: Qiangbin
authors.identifier: http://orcid.org/0000-0001-6589-6328
authors.initials: Q
authors.lastname: Wang
mesh_terms: D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D012834:Silver; D006046:Gold; D004247:DNA
keywords: Au nanorod; DNA self-assembly; chiral optics; plasmonic nanoparticle; surface chemistry