Field enhancement and molecular response in surface‐enhanced Raman scattering and fluorescence spectroscopy

Abstract We present a theoretical analysis of surface‐enhanced Raman scattering and fluorescence emission from chromophoric molecules located at electromagnetic ‘hot spots’ in nanoparticle aggregates. The model combines classical electrodynamic enhancement effects with molecular quantum dynamics and allows us to quantify various molecular cross‐sections and spectral properties. For a model molecule that simulates rhodamine 6G, we find that an electromagnetic Raman enhancement of the order of 10 10 results in an effective Raman cross‐section of the order of 10 −14 cm 2 , in agreement with single‐molecule Raman measurements. Copyright © 2005 John Wiley & Sons, Ltd.