Metal-enhanced fluorescence from copper substrates

In this letter, the authors report the observation of metal-enhanced fluorescence emission from fluorophores deposited on copper (Cu) substrates. Different thicknesses of Cu particulate films (from 1 to 5 nm) were deposited onto glass slides using thermal vapor deposition. Fluorophores positioned in close proximity to the Cu films show fluorescence enhancement as a function of the Cu thickness increases, reaching a maximum (2.5-fold) at approximate to 3 nm. The findings strongly suggest that surface plasmons from Cu can radiate and therefore enhance a fluorophore's spectral properties, similar to observations reported for both silver and gold nanoparticle deposited substrates. (c) 2007 American Institute of Physics.