Quenching particle-fluorophore interactions

Gold nanoparticies can modify the emission of dipole fluorophores through dipole-dipole interactions that are dependent on the gold particle size, shape, and distance from the fluorophore. Further, the effect is dependent on the orientation of the molecular dipole with respect to the particle and the overlap of the emission of the molecule with the particle s absorption spectrum [17]. Either quenching or enhancement of the fluorescence may occur depending on the various parameters that determine the quantum yield of the emission of the fluorophore molecules. These parameters include the excitation electric field E, the radiative rate k, and nonradiative rate k. ... 

---