Convection effects in the BIAcore dextran layer: surface reaction model

Area of Science:

• Biochemistry
• Chemical Engineering
• Physical Chemistry

Background:

• BIAcore devices utilize surface plasmon resonance (SPR) for measuring biochemical reaction kinetics.
• Anomalous measurements in BIAcore devices have led to hypotheses about flow penetration into the dextran layer.
• Enhanced transport due to flow penetration is proposed as an explanation for observed anomalies.

Purpose of the Study:

• To develop and analyze a mathematical model for flow penetration in BIAcore SPR devices.
• To investigate the impact of flow penetration on transport and kinetics within the dextran layer.
• To determine the significance of flow penetration effects on SPR measurements.

Main Methods:

• Development of a mathematical model incorporating flow penetration into the dextran layer.
• Construction of velocity fields within the dextran layer.
• Analysis using asymptotic and singular perturbation techniques for association and dissociation kinetics.
• Derivation and solution of linear and nonlinear integral equations.

Main Results:

• The model accounts for flow penetration and constructs typical velocity fields.
• Analysis in the limit of the surface reaction model (thin dextran layers) was performed.
• Explicit and asymptotic solutions were constructed for physically realizable scenarios.
• The study found that the effects of flow penetration are inherently small.

Conclusions:

• Flow penetration into the dextran layer in BIAcore SPR devices has a negligible effect on measurements.
• The developed model and analysis confirm that transport enhancement is minimal.
• The findings suggest that anomalous SPR measurements are unlikely to be explained by flow penetration alone.