Quantitative and rapid detection of C-reactive protein using quantum dot-based lateral flow test strip

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunotechnology

Background:

• C-reactive protein (CRP) is a key biomarker for inflammation and infection.
• Accurate and rapid CRP quantification is essential for clinical diagnosis.
• Existing detection methods may lack sensitivity, speed, or cost-effectiveness.

Purpose of the Study:

• To develop a novel quantum dot (QD)-based immunoassay for quantitative C-reactive protein (CRP) detection.
• To evaluate the sensitivity, linearity, precision, and accuracy of the developed QD-based lateral flow immunoassay (LFIA).
• To validate the performance of the QD-LFIA using human serum samples.

Main Methods:

• A paper-based lateral flow system utilizing quantum dots (QDs) as fluorescent labels was developed.
• Standard CRP antigens were used to establish assay parameters, including sample volume and detection time.
• Fluorescence intensity was measured using a fluorescence immunoassay analyzer for quantification.
• Assay performance was assessed using standard controls and 135 human serum samples.

Main Results:

• The QD-based immunoassay achieved a limit of detection of 0.30 ng/mL for CRP.
• Quantitative detection showed good linearity in the range of 0.5 ng/mL to 1 μg/mL.
• The assay demonstrated high precision (CV < 15%) and accuracy (mean recovery 102.63%).
• Results from 135 clinical samples showed excellent correlation (r=0.966) with a commercial assay.

Conclusions:

• The developed QD-based LFIA is a reliable platform for rapid, sensitive, and quantitative CRP detection.
• The system is suitable for a broad range of CRP concentrations, from 0.2 to 200 μg/mL.
• This novel assay shows significant potential for point-of-care diagnostics of inflammatory and infectious diseases.