The Effect of an Active Substrate on Nanoparticle‐Enhanced Fluorescence

Proximity of fluorescent molecules to noble metal nanoparticles leads to a strong enhancement of the fluorescent intensity during irradiation with light, a consequence of resonant coupling to localized particle plasmons. In this communication we show that the substrate can have a profound effect on this simple picture, not merely shifting the resonance, but actively reshaping the local fields, and resulting in even larger enhancements.