Galvanic Replacement Reaction to prepare nanoporous Aluminum for UV plasmonics.

Plasmonics applications have been extending into the ultraviolet region of the electromagnetic spectrum. Unfortunately the commonly used noble metals have intrinsic optical properties that limit their use above 350 nm. Aluminum is probably the most suitable material for UV plasmonics and in this work we show that nanoporous aluminum can be prepared starting from an alloy of Mg3Al2. The porous metal is obtained by means of a galvanic replacement reaction. Such a nanoporous metal can be exploited to achieve a plasmonic material for enhanced UV Raman spectroscopy and fluorescence. Thanks to the large surface to volume ratio this material represents a powerful platform for promoting interaction between plasmonic substrates and molecules in the UV.