Facile and versatile substrate fabrication for surface enhanced Raman spectroscopy using spark discharge generation of Au/Ag nanoparticles

A simple, one-step gas phase technique for the fabrication of low-cost substrates with tunable plasmonic enhancement is proposed exploiting the unique peculiarities of spark discharge nanoparticle generation in particle mixing and the ease of particle deposition onto glass microfiber filters. The applicability of the spark-based technique to produce substrates for surface enhanced Raman measurements based on Au/Ag binary nanoparticles is discussed. Our results prove that considerable signal enhancement can be achieved over a large surface area, which can be conveniently tuned due to the inherent ability of the spark generator to mix two or more materials. This versatility in particle generation is well complemented by the direct deposition of the nanoparticles onto a filter medium, which makes the proposed method a low-cost and appealingly simple way for fabricating robust substrates for Raman-based applications.