Electrokinetic effects on detection time of nanowire biosensor

Area of Science:

• Multiphysics modeling
• Nanotechnology
• Biomolecular detection

Background:

• Experimental biomolecular detection at ultralow concentrations shows significant discrepancies with theoretical predictions.
• Existing models often neglect electrokinetic phenomena.

Purpose of the Study:

• To develop a multiphysics model to investigate the role of electrokinetics in biomolecular detection.
• To explain the orders-of-magnitude difference in detection times observed experimentally versus theoretically.
• To explore sensor design and test conditions influencing detection speed.

Main Methods:

• Development of a multiphysics model incorporating electrokinetic effects (electrophoretic force, electroosmotic flow).
• Systematic simulation of electrokinetic effects under varying sensor designs and test conditions.
• Analysis of detection time reduction compared to pure biomolecular diffusion.

Main Results:

• Electrokinetic effects can reduce biomolecular detection time by over 90 times in single nanowire sensors.
• Increasing applied gate voltage or nanowire count further enhances the detection time reduction.
• The model provides a physical explanation for the observed experimental-theoretical discrepancies.

Conclusions:

• Electrokinetics plays a crucial role in accelerating biomolecular detection, especially at ultralow concentrations.
• Optimized combinations of electrokinetic effects and nanowire sensor design can achieve significantly faster detection.
• This research offers a pathway for enhanced sensitivity and speed in biosensing applications.