title: Formation of Au(III)-DNA coordinate complex by laser ablation of Au nanoparticles in solution.
abstract: We discovered that an Au(III)-DNA coordinate complex, Au(III)(DNA-base)2(amine)L, are formed by laser ablation of Au nanoparticles in an aqueous solution containing DNA molecules in the presence of amines and multi-valent cations, where L represents an unknown ligand (either amine or water). Optical absorption spectrum of the solution after laser ablation exhibited a 360 nm absorption peak assined to ligand-->Au(III) charge transfer (LMCT) band of the coordinate complex. The complex is considered to be formed as follows: (1) the DNA molecules are neutralized by binding the multi-valent cations to their negatively charged phosphate groups, and adsorbed on the surface of the Au nanoparticles by a hydrophobic interaction, (2) Au(III) ions are liberated from the Au nanoparticles by laser ablation, and (3) an Au(III) ion reacts with amine and two DNA bases of a DNA molecule into an Au(III)(DNA-base)2(amine)L.
authors.affiliation: East Tokyo Laboratory, Genesis Research Institute, Inc., Chiba, Japan. takeda@clusterlab.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takeda
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kondow
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Mafuné
mesh_terms: D000588:Amines / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D017612:Gold Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D007834:Lasers; D008024:Ligands; D049329:Nanostructures / Q000737:chemistry*; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry
chemical_list: D000588:Amines; D002412:Cations; D017612:Gold Compounds; D008024:Ligands; D014867:Water; D004247:DNA