Electrophoretically deposited gold nanostars substrates for SERS applications. P. 6

Surface enhanced Raman spectroscopy (SERS) is a highly sensitive vibrational spectroscopy technique used for the structural detection of analytes through the amplification of electromagnetic fields generated by the excitation of localized surface plasmons. Several geometries of plasmonic nanoparticles and their assemblies have been explored for enhancing SERS signal. In this study, spherical and star-shaped Au nanoparticles were synthesized by reduction method. Nanoparticles have been deposited on an ITO Glass by employing electrophoresis method to make the SERS substrates. The substrates are then functionalized with a 4mM solution of benzenethiol for 24 hours, then cleaned and dried. UV - VIS spectroscopy is used to study the optical of the nanocomposites. Scanning electron microscopy (SEM) images further confirms the size and morphology of samples. Raman spectra of benzenethiol molecules functionalized on the nanocomposite samples have been measured. A significant enhancement is observed in Raman signals from the benzenethiol molecule that have been attached to the Au nanostars. These substrates find applications in the detection of biomolecules, environmental pollutants and other analyte molecules. (author)