Colocalized dark-field scattering, atomic force and surface-enhanced Raman scattering microscopic imaging of single gold nanoparticles

D. Talaga (1) , M. Comesaña-Hermo (2) , S Ravaine (2) , R a L Vallée (2) , S Bonhommeau (1)

1 ISM - Institut des Sciences Moléculaires
2 CRPP - Centre de recherches Paul Pascal

Colocalized dark-field scattering, atomic force and surface-enhanced Raman scattering microscopic (DFSM, AFM and SERS) imaging of single gold nanoparticles is presented using a home-made instrument. A high numerical aperture total internal reflection objective allows us to probe the polarization-dependence of DFSM spectra associated with individual nanoparticles, which reveal their degree of anisotropy and reflect the morphology and orientation observed on AFM images. Under convenient light excitation, the SERS enhancement efficiency reaches 106–107 for the investigated gold nanorod and ellipsoid, in good agreement with the 103–105 electromagnetic enhancement factor assessed from finite-difference-time-domain (FDTD) calculations and a 102–103 chemical contribution. FDTD calculations also confirm the possibility to reproduce nicely anisotropic behaviours disclosed by DFSM studies using SERS measurements.

Mots clés: Gold nanoparticles; Dark field scattering; Surface-enhanced Raman spectroscopy; Atomic force microscopy; FDTD calculations

Domaines: Optique [physics.optics]

D. Talaga, M. Comesaña-Hermo, S Ravaine, R a L Vallée, S Bonhommeau. Colocalized dark-field scattering, atomic force and surface-enhanced Raman scattering microscopic imaging of single gold nanoparticles. Journal of Optics, 2015, 17 (114006), pp. 1-11. ⟨10.1088/2040-8978/17/11/114006⟩. ⟨hal-01220995⟩