Impedimetric Label-Free Immunosensor on Disposable Modified Screen-Printed Electrodes for Ochratoxin A

Area of Science:

• Electrochemistry
• Biosensor Technology
• Food Safety Analysis

Background:

• Ochratoxin A (OTA) is a prevalent mycotoxin in food products, posing significant health risks.
• Accurate and sensitive detection methods for OTA are essential for regulatory compliance and consumer protection.
• Existing methods for OTA detection can be time-consuming and require specialized equipment.

Purpose of the Study:

• To develop a novel impedimetric label-free immunosensor for the quantitative determination of Ochratoxin A (OTA).
• To utilize disposable screen-printed carbon electrodes (SPCE) modified with gold nanoparticles (AuNPs) for enhanced sensitivity.
• To establish a rapid, sensitive, and cost-effective method for OTA detection in food matrices.

Main Methods:

• Modification of SPCE with gold nanoparticles (AuNPs) and immobilization of anti-OTA antibodies via a cysteamine linker.
• Electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).
• Optimization of the immunosensor by selecting capacitance as the key parameter for OTA quantification.

Main Results:

• The developed immunosensor demonstrated a linear response for OTA detection in the range of 0.3 to 20 ng/mL.
• A low limit of detection (LOD) of 0.25 ng/mL was achieved, suitable for food analysis.
• The immunosensor successfully quantified OTA in red wine samples, showing high sensitivity (lower than 2 μg/kg) consistent with European legislation.

Conclusions:

• The developed impedimetric immunosensor offers a sensitive and label-free approach for OTA quantification.
• Disposable SPCE modified with AuNPs provide a robust platform for electrochemical biosensing applications.
• This technology holds promise for routine monitoring of OTA contamination in various food products, ensuring food safety.