Modeling charge separation in charged nanochannels for single-molecule electrometry.

Area of Science:

• Physical Chemistry
• Nanotechnology
• Fluid Dynamics

Background:

• Microfluidic devices offer precise control over fluid behavior at the nanoscale.
• Understanding solute transport in confined geometries is crucial for developing advanced analytical techniques.

Purpose of the Study:

• To model the transport of electrically charged solute molecules in a nanoslit microfluidic channel.
• To develop a method for simultaneously measuring the hydrodynamic size and electric charge of single molecules.

Main Methods:

• Governing convection-diffusion equation derived and solved numerically.
• Comparison with Taylor-Aris-like approximation for validation.
• Analysis of molecular motion within nanoslit channels with electrostatic surface potential.

Main Results:

• The numerical model accurately predicts solute transport.
• Taylor-Aris-like approximation provides excellent results for small Péclet numbers.
• Demonstrated feasibility of simultaneous size and charge measurement.

Conclusions:

• The developed model and approach are promising for single-molecule characterization.
• Nanoslit microfluidics with electrostatic potential can be utilized for advanced molecular assays.
• This work contributes to the design of novel analytical tools for nanotechnology.