A multiplexed immunoaggregation biomarker assay using a two-stage micro resistive pulse sensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensing Technology

Background:

• Multiplexed biomarker detection is crucial for accurate disease diagnosis and monitoring.
• Current methods often require complex labeling processes and lack simultaneous multi-analyte capabilities.
• Development of rapid, sensitive, and label-free bioassay platforms is highly desirable.

Purpose of the Study:

• To develop and validate an immunoaggregation assay chip for multiplexed biomarker detection.
• To quantify multiple biomarkers simultaneously in a single assay using antibody-functionalized microparticles.
• To demonstrate a label-free, rapid, and quantitative detection method for biomedical research and clinical applications.

Main Methods:

• Utilized antibody-functionalized microparticles (Ab-MPs) with distinct sizes and magnetic properties for specific biomarker capture.
• Employed immunoaggregation of Ab-MPs upon interaction with target biomarkers.
• Implemented a two-stage micro resistive pulse sensor to differentiate and count Ab-MP aggregates based on size and magnetic properties.

Main Results:

• Successfully demonstrated multiplexed detection of human ferritin and mouse anti-rabbit IgG in fetal bovine serum.
• Established a correlation between the volume fraction of Ab-MP aggregates and biomarker concentration.
• Achieved detection ranges of 5.2–208 ng/ml for human ferritin and 3.1–5.12 × 10^4 ng/ml for mouse anti-rabbit IgG.

Conclusions:

• The developed immunoaggregation assay chip enables quantitative, simultaneous detection of multiple biomarkers.
• The label-free approach simplifies the assay process and enhances its applicability.
• This technology holds significant promise for rapid biomarker analysis in clinical diagnostics and biomedical research.