Plasmonic nanoparticles modified by dimercaptostilbene for metamaterials

In this work, we investigated the optical properties and surface chemistry of gold nanoparticles modified by 4,4'-dimercaptostilbene. Dimercaptostilbene was chosen as the molecule which is able to impart the new functional properties to the metasurface constructed based on assembled plasmonic nanoparticles. The influence of dimercaptostilbene concentration on the nanoparticles aggregation was investigated by X-ray photoelectron spectroscopy, UV-vis spectroscopy, transmission electron microscopy and surface enhanced Raman scattering. The interaction of dimercaptostilbene with the gold surface through a sulfur atom as well as the presence of free mercapto groups on the surface were revealed based on obtained experimental data. The effects of pH and halide anions on the Raman response of modified nanoparticles were also checked out showed their good stability in strong acidic medium as well as at high chloride background.