Singlet oxygen phosphorescence enhancement by silver islands films

Optical detection of singlet oxygen, a reactive oxygen species that plays a crucial role in a variety of biomedical processes, is hampered by its extremely low emission probability. Using plasmonic effects induced in silver islands films coated with C₆₀, we have been able to enhance the near-IR phosphorescence of singlet oxygen by a factor of ca. 35. Both an enhanced production of singlet oxygen via plasmon-induced light absorption and the perturbation of its radiative rate constant are shown to account for this effect. The dependence of the enhancement factor on the properties of the silver island films and on the amount of C₆₀ coated are discussed.