Centrifugal disc liquid reciprocation flow considerations for antibody binding to COVID antigen array during...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Microfluidics

Background:

• Heterogeneous immunoassays (HI) are crucial for biomarker detection.
• Integrating HI with microfluidics for point-of-care diagnostics faces challenges in automated fluid control during incubation.
• Sustained, controlled fluid flow is essential for reliable assay results.

Purpose of the Study:

• To investigate liquid reciprocation on a microfluidic centrifugal disc (CD) for automated fluid flow.
• To enable sustained, bidirectional fluid flow for heterogeneous immunoassays (HI) in microfluidic devices.
• To address challenges in assay integration and result interpretation for microfluidic diagnostics.

Main Methods:

• Utilized a microfluidic centrifugal disc (CD) platform.
• Implemented a liquid reciprocation process driven by a rotating motor.
• Characterized fluid flow dynamics experimentally and through simulation.
• Measured volumetric flow rates and shear rates within the HI reaction chamber.

Main Results:

• Achieved sustained, bidirectional fluid flow (μL s^-1) for up to 1 hour using CD liquid reciprocation.
• Demonstrated continuous flow for target molecule incubation in a microarray HI.
• Identified that higher fluid shear rates negatively impacted fluorescence intensity.

Conclusions:

• CD liquid reciprocation offers a viable method for automated fluid control in microfluidic HI.
• Optimizing fluid flow parameters, specifically shear rates, is critical for accurate immunoassay results.
• This approach enhances the integration of HI with microfluidics for point-of-care applications.