SPR induced quenching of the 5D1→7F1 emission of Eu3+ doped gold colloids

The UV-visible absorption spectra and fluorescence spectra have been measured at room temperature to study the luminescence character of Eu3+ ions doped in gold colloids. For solution containing Eu3+, a green fluorescence emission peak is observed at 535 nm when the corresponding excitation wavelength is at 395 nm. When gold colloids were added to the solution containing Eu3+, this fluorescence peak at 535 nm decreases rapidly and then disappeared. We believe that this luminescence quenching is attributed to the coupling between the 5D1→7F1 transitions of Eu3+ and the surface plasmon resonance (SPR) induced absorption in gold nanoparticles.