Development and Optimization of a Quantum Dot-Based Lateral Flow Assay for Hepatitis B Surface Antigen Detection

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Infectious Disease Diagnostics

Background:

• Early detection of Hepatitis B Virus (HBV) is crucial for managing chronic progression and preventing liver complications.
• Current gold-standard methods like ELISA and PCR require specialized infrastructure, limiting accessibility in resource-limited settings.
• Hepatitis B surface antigen (HBsAg) is a key biomarker for HBV infection.

Purpose of the Study:

• To develop and optimize a novel cadmium quantum dots-based lateral flow assay (cadmiumQDs-LFA) for sensitive HBsAg detection.
• To leverage the superior fluorescence properties of cadmium quantum dots (cadmiumQDs) for enhanced analytical performance.
• To provide an accessible diagnostic tool for HBV, particularly for low viral load cases.

Main Methods:

• Functionalization of commercially sourced cadmium quantum dots (cadmiumQDs) with mercaptopropionic acid (MPA) for bioconjugation.
• Integration of optimized cadmiumQDs conjugates into a lateral flow assay (LFA) platform.
• Performance evaluation using clinical serum samples and comparison with a commercial LFA.

Main Results:

• The developed cadmiumQDs-LFA achieved a limit of detection (LOD) of 15.6 ng/mL for HBsAg.
• Clinical evaluation demonstrated a sensitivity of 86.5%, specificity of 95.9%, PPV of 98%, and NPV of 75.3% with 244 samples.
• The cadmiumQDs-LFA showed enhanced detection of low HBsAg levels compared to conventional gold nanoparticles (AuNPs)-based LFAs.

Conclusions:

• The cadmium quantum dots-based lateral flow assay (cadmiumQDs-LFA) presents a highly sensitive and stable platform for HBsAg detection.
• This assay addresses the limitations of existing methods by offering improved performance and potential for wider accessibility.
• The developed cadmiumQDs-LFA is a promising tool for early and effective diagnosis of hepatitis B virus infection.