Microcantilever-Based Label-Free Characterization of Temperature-Dependent Biomolecular Affinity Binding

Area of Science:

• Biophysics
• Materials Science
• Biotechnology

Background:

• Characterizing biomolecular binding kinetics is crucial for understanding biological processes and developing diagnostics.
• Temperature significantly influences molecular interactions, yet real-time, label-free characterization remains challenging.
• Microcantilever-based sensors offer sensitive, label-free detection platforms for biomolecular interactions.

Purpose of the Study:

• To develop and demonstrate a microcantilever-based device for label-free, temperature-dependent characterization of biomolecular affinity binding.
• To investigate the influence of temperature on the binding kinetics between platelet-derived growth factor (PDGF) and its aptamer receptor.
• To obtain quantitative affinity binding parameters, including association and dissociation rate constants, at varying temperatures.

Main Methods:

• Fabrication of a microcantilever sensor with a gold-coated, functionalized surface for target analyte capture.
• Integration of a poly(dimethylsiloxane) (PDMS) microfluidic chamber with an indium tin oxide (ITO) resistive temperature sensor for precise temperature control and monitoring.
• Real-time optical detection of cantilever deflection to measure binding events.
• Infusion of unlabeled analyte (PDGF) into the microfluidic chamber at controlled temperatures to assess binding kinetics.

Main Results:

• Successful label-free characterization of temperature-dependent binding between PDGF and its aptamer receptor.
• Quantification of association rate constant (k_on), dissociation rate constant (k_off), and equilibrium dissociation constant (K_D).
• Demonstration of significant temperature dependencies for all measured affinity binding properties.

Conclusions:

• The developed microcantilever device provides a robust platform for label-free, real-time analysis of temperature-dependent biomolecular binding.
• Temperature plays a critical role in the binding kinetics of PDGF-aptamer interactions, influencing both association and dissociation rates.
• This technology has potential applications in diagnostics, drug discovery, and fundamental studies of molecular interactions under varying thermal conditions.