Rapid Detection of Deoxynivalenol in Dry Pasta Using a Label-Free Immunosensor

Area of Science:

• Electrochemistry
• Biosensor Technology
• Food Safety Analysis

Background:

• Deoxynivalenol (DON) is a prevalent mycotoxin contaminating food staples.
• Accurate and sensitive detection methods are essential for regulatory compliance and consumer protection.
• Existing detection methods may lack the sensitivity or speed required for routine analysis.

Purpose of the Study:

• To develop and optimize a label-free impedimetric immunosensor for sensitive deoxynivalenol (DON) detection.
• To immobilize a monoclonal antibody onto a modified gold electrode using cysteamine and polyamidoamine (PAMAM) dendrimers.
• To evaluate the immunosensor's performance, including sensitivity, limit of detection, and applicability to real food samples.

Main Methods:

• Fabrication of a gold electrode modified with cysteamine and PAMAM dendrimers.
• Immobilization of anti-DON monoclonal antibodies.
• Electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).
• Detection of DON using differential pulse voltammetry (DPV).

Main Results:

• Successful layer-by-layer assembly of the immunosensor was confirmed by CV and EIS.
• PAMAM dendrimers enabled high antibody immobilization, leading to enhanced sensitivity.
• The immunosensor achieved a limit of detection (LOD) of 1 ppb for DON in buffer.
• Analysis of spiked pasta samples yielded an LOD of 50 ppb, below the EU regulatory limit.

Conclusions:

• The developed impedimetric immunosensor offers a sensitive and label-free approach for DON detection.
• PAMAM dendrimers significantly improve immunosensor performance.
• The sensor demonstrates potential for routine analysis of DON in food matrices like pasta, aiding in food safety assurance.