Comparative study of colloidal gold and quantum dots as labels for multiplex screening tests for multi-mycotoxin...

Area of Science:

• Food Science
• Analytical Chemistry
• Biotechnology

Background:

• Mycotoxin contamination in cereals poses significant risks to food safety and human health.
• Multiplex lateral flow immunoassays (LFIA) offer rapid, on-site detection capabilities for multiple analytes.
• Evaluating different nanoparticle labels is crucial for optimizing LFIA performance.

Purpose of the Study:

• To compare quantum dots (QDs) and colloidal gold nanoparticles (CG) as labels for a multiplex LFIA.
• To develop and validate assays for the simultaneous detection of deoxynivalenol (DON), zearalenone (ZEN), and T2/HT2-toxin (T2/HT2) in cereal matrices.
• To assess the analytical characteristics and practical applicability of QD- and CG-based LFIAs.

Main Methods:

• Development of two multiplex LFIAs utilizing the same immunoreagents but different labels (QDs vs. CG).
• Immobilization of antigens and secondary antibodies on nitrocellulose membranes.
• Conjugation of monoclonal antibodies against DON, ZEN, and T2 with CdSeS/ZnS QDs or CG.
• Analysis of naturally contaminated wheat samples to demonstrate assay applicability.

Main Results:

• Both QD- and CG-based LFIAs successfully detected DON, ZEN, and T2/HT2 in wheat, meeting legal limits.
• QD-based LFIA demonstrated higher sensitivity, consumed fewer immunoreagents, and offered better economic benefits.
• QD-based LFIA provided easier result interpretation with a lower false negative rate (<5%).

Conclusions:

• Both QD and CG are suitable labels for multiplex LFIA of mycotoxins in cereals.
• QD-based LFIA is a more advantageous tool for rapid, cost-effective, and sensitive on-site screening of mycotoxins.
• The developed QD-LFIA aligns with regulatory requirements for analytical method performance in screening purposes.