Porous aluminum decorated with rhodium nanoparticles: preparation and use as a platform for UV SERS

Currently, there is a high interest in novel plasmonic platforms and materials able to extend their applicability into the ultraviolet (UV) region of the electromagnetic spectrum. In the UV it is possible to explore the spectral properties of biomolecules that have only a small cross-section in the visible spectral range. However, most plasmonic metals have their resonances at wavelengths 4350 nm. Aluminum and rhodium are two exceptions and therefore interesting candidate materials for UV plasmonics. In this work we developed a simple and low-cost preparation of functional substrates based on nanoporous aluminum decorated with rhodium nanoparticles. We demonstrate that these functionalized nanoporous metal films can be exploited as plasmonic materials for enhanced UV Raman spectroscopy.