Single-molecule identification by spectrally and time-resolved fluorescence detection

Area of Science:

• Spectroscopy
• Photophysics
• Analytical Chemistry

Background:

• Single-molecule fluorescence spectroscopy is crucial for analyzing complex systems.
• Distinguishing between similar molecular species at the single-molecule level presents challenges.

Purpose of the Study:

• To develop a probabilistic method for rapid and efficient single-molecule identification.
• To demonstrate the versatility of the method by analyzing various photon properties.

Main Methods:

• Utilizing simple probability considerations for data analysis.
• Employing Monte Carlo simulations to validate the method's accuracy and efficiency.
• Implementing time-correlated single-photon counting with spectrally resolved detection.

Main Results:

• The proposed method can identify single molecules with high confidence (>99.9%) using fewer than 500 photons.
• Successfully distinguished between four different dye molecules embedded in a polymer film.
• Demonstrated the ability to analyze photon emission wavelength, arrival time, and polarization.

Conclusions:

• The developed methodology offers a robust and efficient approach for single-molecule identification.
• The technique is applicable to various photon properties in fluorescence experiments.
• This method advances the capabilities of single-molecule analysis in chemical and biological research.