Fluorophore-quencher distance correlation functions from single-molecule photon arrival trajectories

Area of Science:

• Physical Chemistry
• Chemical Physics
• Spectroscopy

Background:

• Single-molecule fluorescence spectroscopy provides insights into molecular dynamics.
• Fluorescence lifetime is sensitive to the local environment, including quencher proximity.
• Existing methods for distance correlation analysis can be complex.

Purpose of the Study:

• To generalize and simplify the Yang and Xie method for determining distance correlation functions.
• To develop a more accessible approach for analyzing fluorescence lifetime data influenced by distance-dependent quenching.
• To enable direct extraction of distance correlation functions from photon arrival trajectories.

Main Methods:

• Generalization of the Yang and Xie method for distance correlation analysis.
• Transformation of experimental photon arrival time trajectories.
• Application of inverse Laplace transforms to relate delay time to distance.
• Calculation of correlation functions from transformed data.

Main Results:

• A simplified and generalized method for obtaining distance correlation functions.
• Direct correlation between transformed photon arrival times and distance-dependent fluorescence lifetime.
• Successful application to Förster energy transfer and electron transfer quenching models.

Conclusions:

• The generalized method offers a more straightforward way to analyze distance-dependent fluorescence quenching.
• This technique enhances the study of molecular interactions and energy transfer processes.
• The method is broadly applicable to systems where fluorescence lifetime is modulated by distance.