A molecular spectroscopic description of optical spectra of J-aggregated dyes on gold nanoparticles.

The extinction spectra of J-aggregated dyes on gold nanoparticles, which exhibit interferences between the plasmonic and dye resonances, are simulated by a quantum mechanical model that considers the dye transition to interact through transition-dipole coupling with a continuum of nanoparticle states. This alternative to the classical core-shell dielectric model provides the wavefunctions of the coupled molecule-nanoparticle system and qualitatively explains the enhancement of resonance Raman, fluorescence, and other light-driven processes of molecules adsorbed to nanoparticles.