Distance dependence of surface plasmon-coupled emission observed using Langmuir-Blodgett films.

Surface plasmon-coupled emission (SPCE) is a phenomenon in which fluorophores in the excited state couple with metallic structures resulting in surface plasmons that radiate into the substrate. The authors examined the dependence of SPCE on the distance and orientation of a fluorophore in the nanometric range of the Ag surface. The distance of the fluorophore from the Ag surface was controlled from 2 to 52 nm using Langmuir-Blodgett films. For a horizontally oriented cyanine dye, the experimental intensity and lifetime measurements are in excellent agreement with the detailed theoretical analysis of SPCE.