Analysis of quantum rod diffusion by polarized fluorescence correlation spectroscopy

Area of Science:

• Physical Chemistry
• Materials Science
• Spectroscopy

Background:

• Fluorescent probes are crucial for studying molecular dynamics.
• Understanding rotational and translational diffusion is key to characterizing molecular behavior.
• Quantum rods (Qrods) offer unique photophysical properties for advanced imaging and sensing.

Purpose of the Study:

• To develop a confocal-microscope-based polarized fluorescence correlation spectroscopy (FCS) system.
• To investigate and characterize the polarization dependence of quantum rods (Qrods).
• To analyze the rotational diffusion of Qrods in solution.

Main Methods:

• Development of a confocal-microscope-based polarized FCS system.
• Measurement of polarization dependence on Qrod rotational diffusion.
• Extraction of rotational diffusion parameters by varying solution viscosity.
• Analysis of diffusion over timescales less than 10(-5) s.

Main Results:

• The developed polarized FCS system successfully measured polarization dependence.
• Rotational diffusion of Qrods was characterized in aqueous solution.
• Rotational diffusion parameters were accurately extracted using a dedicated model.
• The influence of solution viscosity on rotational diffusion was quantified.

Conclusions:

• Polarized fluorescence correlation spectroscopy (FCS) is a powerful tool for studying molecular diffusion.
• The system enables detailed characterization of both rotational and translational diffusion.
• This method provides insights into the dynamics of fluorescent probes like Qrods.