FABRICATION OF SURFACE ENHANCED RAMAN SPECTROSCOPY SUBSTRATES BY DIRECT LASER INTERFERENCE PATTERNING

ACEVEDO D.; TOLEDO ARANA; BROGLIA M; LASAGNI A.; MUCKLICH F.; SALAVAGIONE H; EMILIA MORALLON; BARBERO C.

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Workshop; US-Argentina Workshop on Nanomaterials; 2009

INTRODUCTION Raman Spectroscopy is becoming an invaluable tool of molecular structure determination and/or substance identification [1]. Its main advantage over infrared spectroscopy is the possibility of working in aqueous environment, using ultraviolet-visible light as probe. However, the small cross section of Raman scattering still hinder the use of the technique. To avoid that, different enhancement processes are used.[2] Among other surface enhancement trough the use of coinage metal nanostructures is one of the more NH2 SAM of 4-Amino-benzenethiol other, general methods to increase Raman sensitivity. Different methods to build the nanostructures have been devised. On one side, non deterministic methods like electrochemical roughening produce good SERS substrates but with low reproducibility.[3] On the other hand, deterministic methods like photolitography and electrochemical deposition of the metal inside ordered nanoparticle crystals,[4] produce reproducible substrates but are expensive or difficult to master and only produce nanostructures with determined sizes. In the present communication a simple method of nanostructuration is described. It involves the formation of nanostructures in commercial polymer surfaces by laser ablation. The nanostructured surface is then covered with a metal layer by conventional methods. The pattern to be ablated is defined by the interference o several coherent laser beams which originate in the same laser source (Figure 1).