Enhancement of surface enhanced Raman scattering activity of Au nanoparticles through the mesostructured metallic nanoparticle arrays

A self-assembly template with a photoreduction agent embedded along mesostructured silicate-surfactant channels is prepared at the air-water interface. The unique template allows uniform and continuous uptake of metallic precursors into the silicate-surfactant channels from the solution subphase. Upon UV irradiation, the metallic precursors result in near-monodisperse nanoparticles homogeneously arrayed in the mesostructured polyoxometalated-silicate-surfactant (PSS) channels until saturation. With three dimensionally densely packed Au NPs of ca. 1.7 nm in the PSS template, hence a very high number density of surface-enhanced Raman scattering (SERS) hot-spots and large absorptive volume, we show that impressive SERS can be measured with 4-nitrothiophenol adsorbed to Au-NPs@PSS.