title: Correlating electron tomography and plasmon spectroscopy of single noble metal core-shell nanoparticles.
abstract: The 3D structure reconstruction of gold core-silver shell nanoparticles by electron tomography is combined with optical dark-field spectroscopy. Electron tomography allows segmentation of the particles into core and shell subvolumes and facilitates avoiding Bragg diffraction artifacts inherent in 2D images. This advantage proves essential for accurate correlation of plasmon spectra and structure. We find that for the nanoparticles of near-spherical shape studied here the plasmon resonances depend on the relative size of the core and shell, rather than on their exact shapes and concentricity. A remarkable dependence of the spectral shape on the permittivity of the surrounding medium is also demonstrated, suggesting that core-shell nanoparticles can be used as ratiometric sensors with a very high dynamic range.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, 76100, Rehovot, Israel.
authors.forename: Lev
authors.initials: L
authors.lastname: Chuntonov
authors.forename: Maya
authors.initials: M
authors.lastname: Bar-Sadan
authors.forename: Lothar
authors.initials: L
authors.lastname: Houben
authors.forename: Gilad
authors.initials: G
authors.lastname: Haran
mesh_terms: D055032:Electron Microscope Tomography / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D008968:Molecular Conformation; D049329:Nanostructures / Q000648:ultrastructure*; D016062:Porosity; D013057:Spectrum Analysis / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D008670:Metals