Single-Molecule Super-Resolution Fluorescence Lifetime Microscopy

The environment of an emitter has a remarkable impact on its emission properties, and on its lifetime in particular. Emitters coupled with plasmonic nanoparticles show enhanced emission rates, dependent on their proximity and orientation with respect to the nanoparticles, and on the overlap in wavelength between emission and plasmon resonance. We propose a method that combines fluorescence lifetime imaging microscopy with single-molecule super-resolution microscopy to study these properties with spatial resolution below the diffraction limit and picosecond time domain resolution. In order to study single molecule emission in these environments, a nanoscale emitter must be immobilized long enough to confocally scan over its diffraction limited emission. This challenge wil be overcome using fast scanning speeds and careful dye deposition. Combining single-molecule super-resolution microscopy with fluorescence lifetime imaging techniques allows for a new level of precision and isolation that avoids the loss of information associated with ensemble averaging. Our study will provide new insight into the physics of plasmonic environments which will be essential to the development of plasmonic technology in growing fields like biomedicine, nanoscale imaging, and quantum information.