A digital fluorescence immunoassay platform using a self-driven microfluidic cartridge with magnetic capture

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Point-of-Care Diagnostics

Background:

• Self-driven microfluidic devices offer integrated, automated biochemical analysis for point-of-care testing (POCT).
• Challenges include slow diffusion and complex designs needing external actuation for enhanced immunoreactions.

Purpose of the Study:

• To develop a fully integrated, self-driven microfluidic fluorescence immunoassay cartridge (SDMFIC) for precise quantification.
• To utilize magnetic nanoparticles (MNPs) and quantum dots (QDs) for enhanced immunoassay performance.

Main Methods:

• The SDMFIC integrates sample loading, QD-conjugated detection probes, MNP-conjugated capturing probes, and a magnet for immunocomplex capture.
• Manual actuation via an integrated blister pack removes unbound components.
• A portable digital fluorescence imaging system quantifies results.

Main Results:

• The SDMFIC achieved low detection limits (17 pg/mL in saliva, 20 pg/mL in serum) and a wide dynamic range (0.01-200 ng/mL).
• Machine learning models predicted CRP concentrations with 100% accuracy in saliva and 95.24% in serum.

Conclusions:

• The developed SDMFIC enables reliable and precise C-reactive protein (CRP) quantification in various biological samples.
• This technology demonstrates significant potential for advanced point-of-care diagnostic applications.