Coplanar electrode microfluidic chip enabling accurate sheathless impedance cytometry.

Area of Science:

• Biotechnology
• Microfluidics
• Analytical Chemistry

Background:

• Microfluidic impedance cytometry enables non-invasive single-cell analysis.
• Coplanar electrode chips offer miniaturization and low cost but face accuracy challenges due to particle trajectory variations.
• Existing methods often require complex particle focusing systems.

Purpose of the Study:

• To develop an original five-electrode coplanar chip for accurate particle sizing without external focusing.
• To introduce a novel metric derived from chip geometry to correct for particle trajectory effects.
• To demonstrate the chip's efficacy with standard polystyrene beads and yeast cells.

Main Methods:

• Design and fabrication of a novel five-electrode coplanar microfluidic chip.
• Development of a new metric based on the unique signal shape generated by the chip.
• Correction of particle size estimations using the extracted metric.
• Validation with polystyrene beads (5.2, 6, 7 μm) and Saccharomyces cerevisiae.

Main Results:

• The proposed chip enables accurate particle sizing without the need for a focusing system.
• A new metric effectively correlates with particle trajectory, allowing for size correction.
• Achieved coefficient of variations for bead sizing were lower than manufacturer specifications.
• Successfully applied the method to analyze Saccharomyces cerevisiae yeast cells.

Conclusions:

• The novel five-electrode coplanar chip overcomes trajectory-dependent errors in microfluidic impedance cytometry.
• This approach allows for accurate and reproducible single-cell sizing without complex focusing mechanisms.
• The technology holds significant potential for applications in life sciences, particularly in cell analysis.