Membrane-based microfluidic chip constructed and applied in magnetic microparticle anchoring-and-release digital...

Area of Science:

• Biotechnology
• Analytical Chemistry
• Biochemistry

Background:

• Digital immunoassay enables single-molecule protein quantification.
• Traditional methods like single-molecule arrays (SiMoAs) suffer from target loss during droplet distribution.
• Improved methods are needed to minimize signal loss and enhance detection accuracy.

Purpose of the Study:

• To develop a magnetic microparticle anchoring-and-release digital immunoassay for sensitive protein detection.
• To overcome limitations of target loss in conventional digital immunoassays.
• To validate the method's performance in detecting the p24 protein.

Main Methods:

• Utilized a microfluidic chip with a track-etched polycarbonate (PCTE) membrane for droplet generation.
• Modified magnetic microparticles (MMPs) with enzymes for signal production.
• Implemented a two-step process: anchoring MMPs via target protein in 96-well plates, followed by release and digital quantification in the microfluidic chip.

Main Results:

• Successfully applied the method for digital detection of p24 protein.
• Achieved sensitive detection of p24 within the range of 1-100 pg/mL.
• Demonstrated good selectivity and accuracy, indicating reduced signal loss.

Conclusions:

• The magnetic microparticle anchoring-and-release digital immunoassay significantly reduces signal loss compared to traditional methods.
• This advancement offers a more accurate and sensitive approach for digital protein quantification.
• The method shows promise for various applications requiring precise protein detection at the single-molecule level.