An Integrated Approach to Improve the Assay Performance of Quantum Dot-Based Lateral Flow Immunoassays by Using...

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Traditional quantum dot-based lateral flow immunoassays (QD-LFIA) suffer from signal loss due to QD probe issues like blinking and photobleaching.
• Silver deposition on QD surfaces has shown promise in other imaging applications, suggesting potential for enhancing QD performance.

Purpose of the Study:

• To investigate the integration of QD-silver combinations into LFIA systems to improve assay performance.
• To enhance accuracy, signal intensity, and user-friendliness while maintaining cost-effectiveness and practicality.

Main Methods:

• Development of a QD-silver combined LFIA using CdSe/ZnS QDs and an anti-sodium pentachlorophenate antibody.
• Evaluation of assay performance, including signal improvement, detection limit, and false-negative rate for sodium pentachlorophenate detection.
• Comparison of colorimetric and fluorometric detection modes with their respective detection limits and times.

Main Results:

• The QD-silver LFIA demonstrated a 4-fold signal improvement and a 2.5-fold enhancement in detection limit compared to traditional QD-LFIA.
• Achieved a zero false-negative rate for sodium pentachlorophenate analysis in chicken samples.
• Integrated colorimetric (4 ng/mL) and fluorometric (10 ng/mL) detection with acceptable assay times (12-27 min).

Conclusions:

• The QD-silver combination effectively overcomes limitations of traditional QD-LFIA, offering enhanced sensitivity and accuracy.
• This approach provides an inexpensive, versatile, and sensitive alternative to conventional fluorescence LFIA.
• The developed QD-silver LFIA is suitable for practical, rapid, and reliable detection applications.