Surface-enhanced luminescence from Eu³⁺ complex nearby Ag colloids

Abstract.

The effect of colloidal dispersion of silver on the luminescent properties of Eu (III) complex with pyridine-3,5-dicarboxylic acid (PyDC) was investigated. The luminescence from Förster type europium complex was enhanced several times with the presence of Ag colloid and the enhancement factor showed Ag concentration dependence. The observed enhancement effect was discussed in view of surface-enhancement effect and optical absorption due to surface plasmon resonance, both arising from excitation of surface plasmon polariton. The coordination structure around Eu (III) ion was also affected with the presence of Ag colloid, which induced the change in the intensity ratio between two emission bands of ⁵ D ₀ → ⁷ F ₁

and ⁵ D ₀ → ⁷ F ₂ transitions of Eu (III) ion.