Surface-plasmon-mediated single-molecule fluorescence through a thin metallic film

Phys Rev Lett. 2005 Jan 21;94(2):023005. doi: 10.1103/PhysRevLett.94.023005. Epub 2005 Jan 19.

Abstract

We demonstrate that fluorescence of single molecules in the nanometric vicinity of a thin gold film can be effectively excited and detected through the film with an epi-illumination scanning confocal microscope. A full theoretical treatment of the fluorescence signal indicates that both excitation and emission are surface-plasmon mediated. Remarkably, the number of photons detectable from chromophores perpendicular to the interface is enhanced by the presence of the metal.