SERS active Ag-SiO₂ nanoparticles obtained by laser ablation of silver in colloidal silica.

ABSTRACT: Highly stable Ag-SiO₂ nanoparticle composites were first obtained by laser ablation of a silver target in an aqueous colloidal dispersion of silica and examined by UV-vis absorption spectroscopy, transmission electron microscopy and Raman spectroscopy. The surface enhanced Raman scattering (SERS) activity of these nanocomposites was tested using 2,2'-bipyridine as a molecular reporter and excitation in the visible and near-IR spectral regions. The computational DFT approach provided evidence of ligand adsorption on positively charged adatoms of the silver nanostructured surface, in a very similar way to the metal/molecule interaction occurring in the corresponding Ag(I) coordination compound.

SUBMITTER: Gellini C 

PROVIDER: S-EPMC6142779 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature