Relocating Single Molecules in Super-Resolved Fluorescence Lifetime Images near a Plasmonic Nanostructure

Abstract

Single-molecule localization microscopy is a powerful technique with vast potential to study light-matter interactions at the nanoscale. Nanostructured environments can modify the fluorescence emission of single molecules and the induced decay-rate modification can be retrieved to map the local density of optical states (LDOS). However, the modification of the emitter’s point spread function (PSF) can lead to its mislocalization, setting a major limitation to the reliability of this approach. In this paper, we address this by simultaneously mapping the position and decay rate of single-molecules and by sorting events by their decay rate and PSF size. With the help of numerical simulations, we are able to infer the dipole orientation and to retrieve the real position of mislocalized emitters. We have applied our ap-proach of single-molecule fluorescence lifetime imaging microscopy (smFLIM) to study the LDOS modification of a silver nanowire over a field of view of ~10 µm2 with a single-molecule localizatio...