title: A quantitative study of the environmental effects on the optical response of gold nanorods.
abstract: The effects of the dielectric environment on the optical extinction spectra of gold nanorods were quantitatively studied using individual bare and silica-coated nanorods. The dispersion and amplitude of their extinction cross-section, dominated by absorption for the investigated sizes, were measured using spatial modulation spectroscopy (SMS). The experimental results were compared to calculations from a numerical model that included environmental features present in the measurements and the morphology and size of the corresponding nanorods measured by transmission electron microscopy. The combination of these experimental and theoretical tools permits a detailed interpretation of the optical properties of the individual nanorods. The measured optical extinction spectra and the extinction cross-section amplitudes were well reproduced by the numerical model for silica-coated gold nanorods, for which the silica shell provides a controlled environment. In contrast, additional environmental factors had to be assumed in the model for bare nanorods, stressing the importance of controlling and characterizing the experimental conditions when measuring the optical response of bare surface-deposited single metal nanoparticles.
authors.affiliation: Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3, Canada.
authors.forename: Yevgeniy R
authors.initials: YR
authors.lastname: Davletshin
authors.forename: Anna
authors.initials: A
authors.lastname: Lombardi
authors.forename: M Fernanda
authors.initials: MF
authors.lastname: Cardinal
authors.forename: Vincent
authors.initials: V
authors.lastname: Juvé
authors.forename: Aurélien
authors.initials: A
authors.lastname: Crut
authors.forename: Paolo
authors.initials: P
authors.lastname: Maioli
authors.forename: Luis M
authors.initials: LM
authors.lastname: Liz-Marzán
authors.forename: Fabrice
authors.initials: F
authors.lastname: Vallée
authors.forename: Natalia
authors.initials: N
authors.lastname: Del Fatti
authors.forename: J Carl
authors.initials: JC
authors.lastname: Kumaradas
mesh_terms: D017753:Ecosystem; D004574:Electromagnetic Fields; D006046:Gold / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects*; D012031:Refractometry; D012542:Scattering, Radiation
chemical_list: D006046:Gold