Synthesis and characterization of Raman active gold nanoparticles

Luminescent and Raman active gold-based nanoparticles were synthesized by the chemical adsorption of a Raman reporter molecule on gold colloids. 10 nm diameter gold nanoparticles were functionalized with Rhodamine 6G molecules and covered with a polyelectrolyte multilayer. A full characterization of their dimension and chemical composition was performed by scanning electron microscopy and X-ray photoelectron spectroscopy. Raman measurements put in evidence the intense signal coming from the dye molecules adsorbed on the nanoparticle surface. Moreover, laser scanning confocal microscopy analysis reveals the intrinsic luminescence of the dye allowing the use of these nanoparticles for multimodal imaging.