Measuring the distance dependence of the local electromagnetic field from silver nanoparticles

The distance dependence of the local EM field associated with 84+/-5 nm silver particles is characterized by monitoring spectral shifts in the plasmon resonance due to changes in local dielectric environment, which was controlled by coating the particles with silica layers of various thicknesses. The local EM field that extends beyond the physical boundaries of the particles is defined as that providing feedback between the local environment and the electron oscillations in a particle.