Surface-Enhanced Raman Scattering Substrates: Fabrication, Properties, and Applications

Abstract

Recent advancements in nanotechnology largely enabled fabrication of plasmonic nanostructures of desired structural features and substantially improved the sensitivity and selectivity of the conventional optical sensing techniques. The plasmonic nanostructure mitigates the limitation of weak scattering cross-section in Raman spectroscopy via electromagnetic as well as chemical enhancement mechanism. The plasmonic nanostructure combined with the Raman spectroscopy technique, popularly known surface-enhanced Raman scattering spectroscopy, has been now established as an effective tool for molecular finger printing of analyte molecule and find applications diverse areas, ranging from biosensors to art. This chapter explains the mechanism behind the surface-enhanced Raman scattering spectroscopy with an emphasis on the factors contributing towards the enhancement in the Raman signal. Further, an account of the difference between conventional and surface enhanced Raman spectroscopy is presented. The role of hot spots and the rationale behind the choice of metal nanoparticles for surface-enhanced Raman scattering substrates is described. In addition, various approaches adopted for the fabrication of substrates in 1D, 2D, and 3D is explained in detail. A detailed account of a few emerging areas wherein this technique finds applications is also given in the chapter.