Simple density functional approach to adsorption of biomolecules on solid surfaces

Area of Science:

• Physical Chemistry
• Biophysical Chemistry
• Materials Science

Background:

• Modeling biomolecule adsorption is crucial for understanding biological interfaces.
• Existing models may not fully capture the complex interactions between ions and biomolecules.
• A need exists for a versatile theoretical framework to predict adsorption behavior.

Purpose of the Study:

• To develop a simple density functional approach for modeling biomolecule adsorption.
• To investigate the role of associative bonding between ions and chain molecules.
• To analyze the structure of adsorbed layers, excess adsorption isotherms, and double-layer capacitance.

Main Methods:

• Utilizing a three-component mixture model including spherical ions and chain molecules.
• Applying the statistical associating fluid theory to model associative bonding.
• Calculating adsorption isotherms and double-layer capacitance.

Main Results:

• The model successfully describes the adsorption of biomolecules.
• Associative bonding significantly influences the structure of adsorbed layers.
• Predictions for excess adsorption and capacitance are obtained.

Conclusions:

• The density functional approach provides a valuable tool for studying biomolecule adsorption.
• The statistical associating fluid theory effectively models ion-chain interactions.
• This framework aids in understanding interfacial phenomena in biological systems.