title: Observation of spectral anisotropy of gold nanoparticles.
abstract: Metallic nanoparticles synthesized by solution-phase chemistry usually exhibit various polygonal morphologies. The shape is known to have a great impact on a nanoparticle's optical properties, for instance, the surface plasmon resonance frequency. It remains unclear, however, whether the scattering spectrum of nanoparticles is generally anisotropic in the far field as a result. This simple question turns out to be extremely challenging to address because of the particle-to-particle shape inhomogeneity in a bulk sample, and the high sensitivity of surface plasmon resonance to local environments. We report the observation of scattering angle-dependent spectra using a newly developed single-particle tracking spectroscopy (SPS). Furthermore, we show that SPS has provided a way to directly visualize the rotational random walk of individual gold nanoparticles in water for the first time.
authors.affiliation: Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: Hu
authors.initials: H
authors.lastname: Cang
authors.forename: Daniel
authors.initials: D
authors.lastname: Montiel
authors.forename: C Shan
authors.initials: CS
authors.lastname: Xu
authors.forename: Haw
authors.initials: H
authors.lastname: Yang
mesh_terms: D016880:Anisotropy; D003116:Color; D006046:Gold / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D006046:Gold