Metal nanoparticle-enhanced room temperature phosphorescence of diiodofluorescein on the filter paper substrate

Metal-enhanced room temperature phosphorescence of diiodofluorescein was first observed on filter paper surface. The phosphorescence intensity is 2.5-fold brighter from diiodofluorescein on silver nanoparticles-deposited filter paper as compared with an identical control sample without silver nanoparticles. Furthermore, enhanced absorption was also observed for the same system. Our findings suggest that both singlet and triplet states can couple to surface plasmons and enhance phosphorescence quantum yields at room temperature, as well as to increase the excitation rate of lumophores at room temperature.