Accelerating fluorescence resonance energy transfer with plasmonic nanoresonators

We show that well-defined plasmonic nanoresonator made of two gold nanoparticles, separated by less than the particle radius, can be used to significantly accelerate fluorescence energy transfer (FRET). While ensembles of nanoresonators with multiple FRET systems attached exhibit FRET acceleration similar to isolated gold nanoparticles, model calculations reveal different, spatially non-uniform rate enhancement distributions around individual nanostructures with both regions of FRET rate enhancement and suppression. This underlines the importance of precise positional control of both donor and acceptor with respect to the nanoresonator to make full use of its potential for FRET acceleration.