Achieving High Temporal Resolution in Single-Molecule Fluorescence Techniques using Plasmonic Nanoantennas

Achieving sub-millisecond temporal resolution to monitor fast molecular dynamics has been a persistent challenge in single-molecule fluorescence spectroscopy. The fluorescence brightness, or the number of photons detected per second and per molecule, is the key parameter that determines the temporal resolution of these techniques. Unfortunately, conventional confocal microscopes fall short in providing the brightness required for sub-millisecond monitoring. In a recent article published in Advanced Optical Materials, we present a method for achieving high temporal resolution in single-molecule fluorescence techniques using optical horn antennas.

Significance:

- We demonstrate the use of plasmonic nanoantennas to achieve a remarkably high level of collection efficiency, reaching over 90% of the total emitted light from a single diffusing molecule.

- With a fluorescence brightness of 2 million photons/s/molecule, we can perform fast FCS measurements and observe single molecules within individual diffusion bursts at microsecond binning time.

- This technological advancement expands the application of plasmonic antennas and zero-mode waveguide nanoapertures towards higher fluorescence count rates and faster temporal resolutions

Freely available on ArXiv 2303.00416