Numerical and experimental study of fluorescence enhancement with silica encapsulated metallic nanoparticles

Abstract

A metallic nanoparticle can act as an optical antenna, enhancing the fluorescence of nearby fluorescent molecules. We investigate the effects of a silica spacer layer on this fluorescence enhancement. Numerical simulations using the Finite- Difference Time Domain (FDTD) method is performed to find the optimum size for the gold nanosphere core as well as the optimum thickness of the silica shell. We present the dependence of radiative decay rate and quantum yield of the fluorescent molecule with respect to varying silica layer thicknesses. © 2010 Copyright SPIE - The International Society for Optical Engineering.