Single-Molecule FRET at 10 MHz Count Rates

Area of Science:

• Biophysics
• Nanotechnology
• Molecular Biology

Background:

• Single-molecule Förster resonance energy transfer (smFRET) experiments are limited by photon count rate, restricting temporal resolution.
• Observing fast biological processes requires higher photon count rates and improved dye stability.

Purpose of the Study:

• To enhance photon count rates for smFRET by utilizing DNA nanoantennas.
• To enable the study of ultrafast biomolecular dynamics and processes.

Main Methods:

• Employing DNA nanoantennas positioned between plasmonic nanoparticles to increase fluorescence.
• Utilizing smFRET to monitor protein folding/binding and DNA hybridization dynamics.

Main Results:

• Achieved photon count rates of approximately 10 MHz, an order of magnitude improvement.
• Observed coupled folding and binding of intrinsically disordered proteins with ~100 μs lifetimes.
• Measured DNA hybridization transition path time of 17 μs.
• Demonstrated increased photostability allowing for seconds-long data acquisition.

Conclusions:

• DNA nanoantennas significantly enhance smFRET capabilities, enabling the study of previously unobservable ultrafast biophysical processes.
• The modular DNA origami platform is adaptable for diverse biomolecular studies.
• This approach offers a promising avenue for advancing our understanding of molecular mechanisms.