Effect of noble metal core plasmons on spectroscopic properties of organic shell

The plasmon-exciton coupling in composite nanoparticles (NPs) was studied for different geometry noble metal core (Ag, Au) coated with the layer of cyanine dye (TC) in J-aggregate state. For such a system peak or dip in the absorption spectrum is observed on the wavelength corresponding to J-aggregate but photoluminescence is completely quenched by the metal core. For three-component nanoparticles with J-aggregate shell separated from the metal core with monomolecular dielectric layer (TMA) the interaction of metal plasmons and J-aggregate excitons is maintained meanwhile luminescence quenching is weakened. Fast dynamics (few picoseconds) in transient absorption of three-component nanoparticles was observed. Raman spectra of two-component and three-component nanoparticles were measured and conditions of observing Surface Enhanced Raman Scattering (SERS) are discussed.