Numerical correction of detector channel cross-talk using full-spectrum fluorescence correlation spectroscopy

Area of Science:

• Biophysics
• Analytical Chemistry
• Spectroscopy

Background:

• Fluorescence correlation spectroscopy (FCS) analyzes fluorophore dynamics via fluorescence fluctuations.
• Spectral overlap in traditional FCS causes detector cross-talk, compromising molecular interaction measurements.
• Accurate quantification of molecular dynamics is crucial in various scientific disciplines.

Purpose of the Study:

• To present the experimental implementation of full-spectrum fluorescence correlation spectroscopy (FCS).
• To demonstrate the use of multivariate data analysis for correcting detector cross-talk in FCS.
• To validate the methodology for analyzing complex fluorescent mixtures and identifying unknown components.

Main Methods:

• Full-spectrum fluorescence correlation spectroscopy (FCS) was experimentally realized.
• Multivariate data analysis was employed to numerically correct spectral cross-talk between detector channels.
• The method was applied to measure the diffusion constant of labeled polystyrene in hydroxypropyl cellulose with a persistent dye.

Main Results:

• The developed full-spectrum FCS successfully corrected for detector cross-talk, enabling accurate signal isolation.
• The diffusion constant of labeled polystyrene was accurately determined in a complex mixture.
• The methodology demonstrated the capability to isolate and characterize signals from unanticipated sample components.

Conclusions:

• Full-spectrum FCS coupled with multivariate analysis provides a robust solution for accurate measurements in the presence of spectral overlap.
• This technique enhances the reliability of studying molecular interactions and dynamics in complex systems.
• The approach offers potential for identifying and characterizing unknown fluorescent species in samples.