title: Synthesis, electron tomography and single-particle optical response of twisted gold nano-bipyramids.
abstract: A great number of works focus their interest on the study of gold nanoparticle plasmonic properties. Among those, sharp nanostructures appear to exhibit the more interesting features for further developments. In this paper, a complete study on bipyramidal-like gold nanostructures is presented. The nano-objects are prepared in high yield using an original method. This chemical process enables a precise control of the shape and the size of the particles. The specific photophysical properties of gold bipyramids in suspension are ripened by recording the plasmonic response of single and isolated objects. Resulting extinction spectra are precisely correlated to their geometrical structure by mean of electron tomography at the single-particle level. The interplay between the geometrical structure and the optical properties of twisted gold bipyramids is further discussed on the basis of numerical calculations. The influence of several parameters is explored such as the structural aspect ratio or the tip truncation. In the case of an incident excitation polarized along the particle long axis, this study shows how the plasmon resonance position can be sensitive to these parameters and how it can then be efficiently tuned on a large wavelength range.
authors.affiliation: Laboratoire de Chimie, ENS Lyon, CNRS, Université Claude Bernard Lyon 1, Université de Lyon, UMR 5182, 46 allée d'ltalie, 69364 Lyon, France.
authors.forename: Julien R G
authors.initials: JR
authors.lastname: Navarro
authors.forename: Delphine
authors.initials: D
authors.lastname: Manchon
authors.forename: Fréderic
authors.initials: F
authors.lastname: Lerouge
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Cottancin
authors.forename: Jean
authors.initials: J
authors.lastname: Lermé
authors.forename: Christophe
authors.initials: C
authors.lastname: Bonnet
authors.forename: Fréderic
authors.initials: F
authors.lastname: Chaput
authors.forename: Alexis
authors.initials: A
authors.lastname: Mosset
authors.forename: Michel
authors.initials: M
authors.lastname: Pellarin
authors.forename: Stephane
authors.initials: S
authors.lastname: Parola
mesh_terms: D055032:Electron Microscope Tomography; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold