Nanoscale near-field infrared spectroscopic imaging of silica-shell/gold-core and pure silica nanoparticles

作者：Nuno Zachary; Hessler Brandon; Heiberg Bryan; Damato Ralph; Dunlap Terry; Shon Young Seok; Abate Yohannes^*

来源：Journal of Nanoparticle Research, 2012, 14(3): 766.

DOI：10.1007/s11051-012-0766-z

• Silica-shell
• Scattering-type scanning near-field optical microscopy (s-SNOM)
• Coating layers
• Core-shell nanoparticles
• Near-field infrared imaging

Spectroscopic near-field imaging of single silica-shell/Au-core and pure silica nanoparticles deposited on a silicon substrate is performed in the infrared wavelength range (lambda = 9-11 mu m) using scattering-type scanning near-field optical microscopy (s-SNOM). By tuning the wavelength of the incident light, we have acquired information on the spectral phonon-polariton resonant near-field interactions of the silica-shell/Au-core and pure silica nanoparticles with the probing tip. We made use of the enhanced near-field coupling between the high index Au-core and the probing tip to achieve spectral near-field contrast of the thin silica coating (thickness < 10 nm). Our results show that spectroscopic imaging of thin coating layers and complex core-shell nanoparticles can be directly performed by s-SNOM.

• 出版日期2012-3