Zeta potential characterization using commercial microfluidic chips.

Area of Science:

• Microbiology
• Biophysics
• Materials Science

Background:

• Bacterial surface charge is crucial for microbial interactions but difficult to measure directly.
• Zeta potential measurements are commonly used but existing methods are costly or require specialized facilities.
• Current techniques are often ill-suited for non-spherical samples like bacteria.

Purpose of the Study:

• To develop a facile and accessible method for electrokinetic characterization of particles and cells.
• To enable accurate zeta potential measurements using commercially available microfluidic chips and open-source workflows.
• To overcome the limitations of existing costly and specialized zeta potential measurement tools.

Main Methods:

• Utilized commercially available PMMA microfluidic chips for zeta potential measurements.
• Employed open-source data analysis workflows for characterization.
• Calibrated measurements using a Zetasizer and tested with polystyrene beads and *Escherichia coli*.

Main Results:

• The novel workflow demonstrated increased measurement reproducibility.
• Zeta potential measurements were made more accessible, eliminating the need for microchannel fabrication.
• Measured zeta potentials for beads and *E. coli* aligned with established literature values.

Conclusions:

• This workflow provides a powerful and broadly applicable tool for critical zeta potential measurements.
• The method enhances accessibility and reproducibility for characterizing microbial and particle surface charge.
• Facilitates diverse applications requiring accurate electrokinetic characterization of cells and particles.