Wavelength Dependence of Metal-Enhanced Fluorescence

In this paper, metal-enhanced fluorescence (MEF) from 6-propionyl-2-dimethylaminonaphthalene (Prodan) in different solvents when placed in close proximity to silver island films (SIFs), surface-deposited nanoparticles, is studied. We observe that MEF is wavelength dependent: the enhanced emission of Prodan on SIFs in different solvents changes from 1.5- to 3-fold as compared to a glass control sample containing no silver nanoparticles. Our findings strongly suggest that MEF of Prodan in different solvents is correlated with the scattering portion of the extinction spectrum for metallic particles, i.e., the fluorophore couples and radiates through that scattering mode, which further confirms Our laboratories current interpretation of the MEF effect.