Probing the type of anomalous diffusion with single-particle tracking

Area of Science:

• Biophysics
• Chemical Physics
• Physical Chemistry

Background:

• Chemical reactions in living cells often rely on diffusion-driven encounters.
• Diffusion in complex fluids can be anomalous, exhibiting subdiffusion.
• Different subdiffusion types impact reaction timing and equilibria.

Purpose of the Study:

• To develop a straightforward method for determining subdiffusion types from single-particle tracking data.
• To enable quantitative understanding of reactions in complex fluid environments.

Main Methods:

• Analysis of single-particle tracking data.
• Development of a novel approach sensitive to various subdiffusion phenomena, including transient and obstructed diffusion.

Main Results:

• A simple and effective strategy for classifying subdiffusion types was introduced.
• The method demonstrated sensitivity to transient subdiffusion, such as obstructed diffusion below the percolation threshold.
• Validation was performed using both experimental and simulated data.

Conclusions:

• Accurate characterization of subdiffusion is essential for understanding reaction kinetics in complex fluids.
• The presented method offers a practical tool for analyzing single-particle tracking data and identifying diffusion behaviors.