Abstract
A study was conduct to demonstrate observations of the effect of an active substrate on nanoparticle-enhanced fluorescence. The study demonstrated observations that provided information about the dependence of the enhancement of fluorescence from monodisperse silver nanoparticles is altered by the use of a silicon (Si) substrate. The study showed that the variation of the fluorescence enhancement with nanoparticle diameter does not follow that of plasmon excitation, as measured by the optical extinction, when fluorescence measurements are compared with calculations of the response of the silver nanoparticles to incident light. The observations revealed generation of regions of high electrical field intensity near the particle, which dominates the fluorescence enhancement.