Ultra-Sensitive and Label-Free Probing of Binding Affinity Using Recognition Imaging.

Area of Science:

• Biotechnology
• Nanotechnology
• Biophysics

Background:

• Quantifying binding affinity is crucial in biotechnology and pharmacology.
• Existing methods lack ultrasensitivity, nanoscale resolution, and require large sample volumes.
• There is a need for advanced techniques to analyze molecular interactions at the single-molecule level.

Purpose of the Study:

• To develop a novel platform for precise quantification of binding affinity using atomic force microscopy (AFM).
• To visualize and analyze single molecular bindings on nanosize dendrons.
• To achieve ultrasensitive, nanoscale resolution for biomolecular interaction analysis.

Main Methods:

• Utilized AFM-derived recognition imaging to detect and localize single DNA molecules.
• Employed sinusoidal oscillation of the AFM cantilever near resonance for enhanced speed and resolution.
• Developed a label-free, single-molecular biochemical analysis approach.

Main Results:

• Successfully visualized single DNA hybridization events at nanometer resolution.
• Determined the equilibrium dissociation constant for capturing DNA duplexes as 2.4 × 10^-10 M.
• Demonstrated the quantification of biomolecular interactions involving a few hundred molecules.

Conclusions:

• AFM-based recognition imaging offers a powerful tool for ultrasensitive binding affinity quantification.
• The developed platform addresses limitations of traditional methods for analyzing molecular interactions.
• This label-free approach advances single-molecule biochemical analysis in biotechnology and pharmacology.