Gold nano-island arrays on silicon as SERS active substrate for organic molecule detection

摘要

Gold islands forming highly controlled arrays have been fabricated by two potential step electrochemical deposition method using nanopatterned Si surface templates. In the present work, the Raman scattering studies realized using 11-mercaptoundecanoic probe molecule showed that such structures exhibit an enhanced Raman signal compared with nanostructured physical deposited thin gold film on flat silicon substrate and can be valued as surface-enhanced Raman scattering substrates. Besides the more appropriate management of nano-island arrays distribution, the high ratio of their Raman signals can be explain by the epitaxial-like growth mechanism of the metallic nano-islands, clearly showed by X-ray diffraction studies. Furthermore, the substrates enabled repro-ducibility and stability detection due to the chemically assembling of organothiol molecules, the X-ray photoelec-tron spectroscopy studies confirming formation of the thiolate species which corresponds to Au-S bonds, and also, the unwanted 'hot-spots' are missing, which make them suitable for high sensitivity biosensing applications.