Broadband single-molecule excitation spectroscopy.

Area of Science:

• Analytical Chemistry
• Physical Chemistry
• Spectroscopy

Background:

• Single-molecule spectroscopy is a powerful technique for studying molecular heterogeneity and dynamics.
• Traditionally, measuring excitation spectra of single molecules at room temperature has been difficult.
• Existing methods struggle with challenges like molecular blinking and photobleaching.

Purpose of the Study:

• To develop a rapid and robust method for recording single-molecule excitation spectra under ambient conditions.
• To overcome the limitations of previous techniques in measuring excitation spectra at room temperature.
• To demonstrate the utility of the new method for analyzing molecular properties.

Main Methods:

• Development of a broadband Fourier transform approach for excitation spectroscopy.
• Application of the technique to individual molecules under ambient conditions.
• Method designed to be robust against molecular blinking and photobleaching.

Main Results:

• The broadband Fourier method allows rapid recording of single-molecule excitation spectra at room temperature.
• Observed extreme distributions of solvatochromic shifts and distinct spectral shapes in individual molecules.
• The technique's sensitivity and speed are comparable to emission spectroscopy.

Conclusions:

• The broadband Fourier approach significantly advances single-molecule spectroscopy by enabling room-temperature excitation spectral measurements.
• This method provides new insights into molecular heterogeneity and dynamics.
• The technique offers a powerful complementary tool alongside emission spectroscopy for comprehensive single-molecule analysis.