A colorimetric paper-based immunosensor for high-sensitivity C-reactive protein (hs-CRP) detection.

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Immunosensor Technology

Background:

• Cardiovascular diseases (CVDs) pose a significant global health burden.
• High-sensitivity C-reactive protein (hs-CRP) is a validated biomarker for predicting CVD risk.
• Accurate and accessible hs-CRP detection methods are crucial for early risk assessment.

Purpose of the Study:

• To develop a simple, portable, and instrument-free colorimetric immunosensor for hs-CRP detection.
• To utilize a paper-based analytical device (PAD) integrated with immunomagnetic separation (IMS).
• To establish a clinically relevant detection range and high precision for hs-CRP quantification.

Main Methods:

• Development of a sandwich immunoassay utilizing magnetic beads for immunomagnetic separation (IMS).
• Immobilization of capture antibodies on magnetic beads and biotinylation of detection antibodies.
• Enzymatic colorimetric detection using β-galactosidase (βgal) and a sensitive substrate (CRPG).

Main Results:

• Achieved a limit of detection (LOD) of 0.10 mg L^-1 for hs-CRP.
• Established a clinically relevant detection range of 0.30-3.0 mg L^-1.
• Demonstrated high precision (inter- and intraday % RSD < 5%) and reliability in human serum analysis.

Conclusions:

• The developed PAD-based immunosensor provides a simple, portable, and instrument-free method for hs-CRP detection.
• The sensor exhibits sufficient sensitivity and precision for CVD risk assessment.
• This technology holds promise for developing cost-effective screening kits in resource-limited settings.