Metal-enhanced superoxide generation: A consequence of plasmon-enhanced triplet yields

The authors report significant enhancements in the generation of superoxide for fluorophores in close proximity to silver nanoparticles. A distance dependence study of the fluorophores from the metallic nanostructures, combined with carefully chosen control samples, confirms that the enhancements in superoxide generation are due to plasmon-enhanced triplet yields, a consequence of the distance dependent sensitizer extent of excitation. This observation strongly agrees with current models developed by the authors. Given that the generation of superoxide and other oxygen species is important for many chemical and biological applications, then we believe that our findings are likely to fuel a wealth of oxygen-based plasmon-enhanced triplet assays. (C) 2007 American Institute of Physics.