Statistical mechanics of DNA-mediated colloidal aggregation.

Area of Science:

• Statistical mechanics
• Colloidal science
• Biophysics

Background:

• Colloidal systems are widely used in various applications.
• DNA-mediated interactions offer precise control over colloidal assembly.
• Understanding aggregation dynamics is crucial for material design.

Purpose of the Study:

• To develop a statistical mechanical model for DNA-mediated colloidal aggregation.
• To establish a quantitative link between DNA thermodynamics and macroscopic aggregation properties.
• To validate the model against experimental observations.

Main Methods:

• Formulation of a statistical mechanical model for colloidal aggregation.
• Calculation of two-particle binding energy based on DNA hybridization free energy.
• Inclusion of partial ergodicity and angular localization of DNA linkers.
• Derivation of universal functions for aggregate size distribution.

Main Results:

• A general formula for two-particle binding energy was derived.
• Aggregate size distribution was found to be a universal function of binding energy.
• The model successfully predicts aggregation and melting properties.
• Quantitative agreement with experimental data for micron and nanometer particles was achieved.

Conclusions:

• The developed model provides a robust framework for understanding DNA-colloidal systems.
• The study highlights the importance of DNA thermodynamics in controlling aggregation.
• The findings have implications for the design of self-assembling nanomaterials.