Novel highly-performing immunosensor-based strategy for ochratoxin A detection in wine samples.

Area of Science:

• Food Science
• Analytical Chemistry
• Biosensors

Background:

• Ochratoxin A (OTA) contamination in food and feed is a significant concern.
• High-performance detection methods are crucial for quality assessment and safety.
• Electrochemical immunosensors offer a promising avenue for sensitive OTA detection.

Purpose of the Study:

• To develop and compare two indirect competitive enzyme-linked immunosorbent assay (ELISA) strategies for ochratoxin A (OTA) electrochemical immunosensors.
• To evaluate different OTA immobilization procedures and antibody types.
• To assess the impact of enzyme labels and sample matrix on immunosensor performance.

Main Methods:

• Development of indirect competitive ELISA-based electrochemical immunosensors for OTA detection.
• Comparison of avidin/biotin-OTA and bovine serum albumin (BSA)-OTA immobilization methods.
• Evaluation of polyclonal (PAb) and monoclonal (MAb) antibodies against OTA.
• Assessment of alkaline phosphatase (ALP) and horseradish peroxidase (HRP)-labelled secondary antibodies.

Main Results:

• Avidin/biotin-OTA immunosensors exhibited enhanced performance over BSA-OTA conjugates.
• Monoclonal antibodies (MAb) demonstrated significantly lower IC50 values compared to polyclonal antibodies (PAb).
• HRP-labelled immunosensors showed better stability in the presence of wine matrix interferences compared to ALP-labelled ones.
• Detection limits were 0.7 ng/mL for HRP and 0.3 ng/mL for ALP, validating their use as screening tools.

Conclusions:

• Electrochemical immunosensors utilizing avidin/biotin immobilization and MAb are effective for OTA detection.
• HRP-labelled immunosensors are more robust in complex matrices like wine due to reduced interference.
• These developed immunosensors serve as valuable screening tools for monitoring OTA contamination in wine.