The surface enhanced Raman spectroscopic study of the adsorption of C70 on the gold nanoparticles

Surface enhanced Raman spectra (SERS) of C(70) adsorbed on the gold nanoparticles coated on the filter paper were obtained by employing pyridine molecule as medium. As a new SERS substrate, dried gold coated filter paper has a high SERS activity, of which enhancement factor can be up to 8.2x10(6). When the C(70) molecule is adsorbed on the gold nanoparticle surface, its symmetry is reduced. Different orientations on the surface of gold nanoparticles will lead to different symmetry lowering. Generally, symmetry lowering may lead to the splitting of the Raman bands due to the degenerate modes. It was demonstrated that the C(70) molecule was adsorbed on its pentagonal face with its long axis perpendicular to the gold nanoparticles surface. Its surface enhanced Raman spectral behavior is consistent with the analysis based on the group theory.