Design, fabrication and test of a pneumatically controlled, renewable, microfluidic bead trapping device for...

Area of Science:

• Microfluidics
• Analytical Chemistry
• Biotechnology

Background:

• Bead-based assays are crucial for various applications, but require efficient and reliable microfluidic systems.
• Existing systems often face challenges with bead handling, reusability, and assay uniformity.

Purpose of the Study:

• To design, fabricate, and test a novel pneumatically controlled, renewable microfluidic device for bead-based assays.
• To evaluate the device's performance in automated sequential injection analysis systems.
• To demonstrate the device's utility for immunoassay applications.

Main Methods:

• A microfluidic device with a "brick wall" pillar array was fabricated for micro-filter functionality.
• Pneumatic control was used to deform an elastomeric membrane, trapping beads (>5 μm) for assay.
• Mouse IgG was used as a model analyte for on-chip fluorescent and electrochemical immunoassays.

Main Results:

• The device demonstrated effective bead trapping and release, enabling device renewal.
• On-chip fluorescent immunoassay showed narrow fluorescence signal intensity distribution, indicating high uniformity.
• Electrochemical immunoassay achieved a detection limit of 1 ppb with good reliability and repeatability.

Conclusions:

• The developed microfluidic device offers a renewable and automated platform for bead-based assays.
• The device shows significant potential for high-uniformity immunoassays and other micro-bead applications.
• This work paves the way for novel microfluidic designs in diagnostics and analytical chemistry.