Label-Free Probing of Molecule Binding Kinetics Using Single-Particle Interferometric Imaging

Area of Science:

• Biophysics
• Analytical Chemistry
• Molecular Biology

Background:

• Probing molecular interactions is crucial for drug discovery, environmental monitoring, and understanding biological systems.
• Detecting these interactions, particularly for small molecules, presents significant technical challenges.
• Existing methods often require molecular labeling, complicating the process.

Purpose of the Study:

• To develop and present a novel label-free optical imaging technology.
• To demonstrate the capability of this technology in measuring molecule binding kinetics.
• To provide a versatile platform for various molecular interaction analyses.

Main Methods:

• Utilizes optical imaging to capture interferometric scattering patterns of particles.
• Drives free-moving particles into oscillations using an alternating electrical field.
• Tracks charge-sensitive variations in oscillation amplitude with sub-nanometer precision.

Main Results:

• Successfully measured binding kinetics of small molecules and metal ions to surfaces.
• Quantified protein-protein binding kinetics using the developed method.
• Achieved high precision in detecting molecular binding events without labels.

Conclusions:

• The developed label-free optical imaging technology offers a promising platform for molecular interaction analysis.
• This method facilitates efficient screening of small-molecule drugs and detection of environmental pollutants.
• It enables detailed probing of protein conformational changes and binding dynamics.