Plasmon-mediated excitation modulation of FRET by silver nanoshell

Abstract The Forster resonance energy transfer (FRET) between a donor and an acceptor affected by a silver nanoshell (SNS) is investigated theoretically, based on the classical electromagnetic theory. Using the dyadic Green's functions, the enhancement on the excitation rate of the donor is studied. In addition, the apparent quantum yield, in terms of the radiative and nonradiative decay rates, for the acceptor's emission affected by SNS is analyzed. The overall result shows that the plasmon-mediated FRET occurs only when the emission band of the donor and the excitation band of acceptor coincide with one of the plasmon modes (e.g. the dipole and quadrupole modes) of SNS. The distance-dependent decay of the energy transfer rate in the presence of SNS is milder than the inverse sixth power. There is an optimal distance between the acceptor and SNS to obtain the maximum enhancement factor for the long-range plasmon-mediated FRET.