title: Metal-ion induced transition from multi- to single-bilayer tubes in histidine bearing lipids and formation of monodisperse Au nanoparticles.
abstract: We report that a histidine based cationic lipid forms multi-bilayer nanotubes and the addition of metal ions such as Cu(2+) and Au(3+) induces transformation into single-bilayer nanotubes owing to coordination of the metal ions on the nanotube surface. The morphological transition was detected with X-ray scattering and electron microscopy. IR showed that the metal coordination is presumably the major driving force. The reduction of Au(3+) ions on the tube surface produced gold nanoparticles attached on the nanotube surface. The nanoparticle was almost monodisperse with the average diameter of 1.7 nm and the standard deviation σ of 0.29, which is remarkably narrower than that of previously reported lipid systems. The obtained particles were stable and no further aggregation and growth was observed after one week, providing a powerful and facile tool for producing nanoparticles in a wide range of applications.
authors.affiliation: Department of Chemistry and Biochemistry, Faculty of Environmental Engineering, University of Kitakyushu, 1-1, Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishimura
authors.forename: Takuma
authors.initials: T
authors.lastname: Matsuo
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sakurai
mesh_terms: D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D008055:Lipids; D006639:Histidine; D006046:Gold; D003300:Copper