Direct and multiplex quantification of protein biomarkers in serum samples using an immuno-magnetic platform

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biotechnology

Background:

• Early cancer diagnostics rely on detecting circulating cancer-associated antigens.
• Current multiplex assays often require sample pre-treatment and lack sufficient sensitivity.
• There is a need for direct, ultrasensitive, and multiplexed methods for biomarker quantification.

Purpose of the Study:

• To develop a direct and ultrasensitive multiplex assay for quantifying trace amounts of circulating cancer-associated antigens in serum.
• To utilize an immuno-magnetic platform with novel turn-on fluorophores for enhanced detection.
• To establish a versatile tool for early disease diagnostics.

Main Methods:

• Development of an immuno-magnetic platform for capturing target antigens on magnetic nanoparticles.
• Utilizing specific immuno-interactions between antigens, capture, and detection antibodies.
• Labeling of the immuno-assembly with synthesized turn-on fluorophores for fluorescence detection.
• Simultaneous quantification of multiple antigens like alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and prostate specific antigen (PSA).

Main Results:

• Achieved a limit of detection (LOD) in the femtomolar (fM) regime without sample pre-treatment.
• Demonstrated efficient differentiation of target antigens from complex protein matrices.
• Successfully quantified multiple cancer-associated antigens simultaneously using only 6 μL of serum within an hour.

Conclusions:

• The developed immuno-magnetic assay is direct, ultrasensitive, and capable of multiplexed biomarker detection.
• This assay offers a high signal-to-noise ratio and broad applicability for early disease diagnostics.
• The novel system serves as a universal and useful tool for clinical applications in cancer screening.