Nafion-Immobilized Functionalized MWCNT-based Electrochemical Immunosensor for Aflatoxin B₁ Detection

Area of Science:

• Electrochemistry
• Biosensing
• Food Safety

Background:

• Aflatoxin B1 (AFB1) contamination in food poses significant health risks and challenges for accurate, onsite monitoring.
• Existing detection methods often lack the sensitivity, stability, or cost-effectiveness required for widespread food safety applications.

Purpose of the Study:

• To develop an ultrasensitive electrochemical immunosensor for the trace detection of AFB1 in complex food matrices.
• To enhance sensor performance through the synergistic use of Nafion and functionalized multiwalled carbon nanotubes (MWCNTs).

Main Methods:

• Fabrication of a Nafion-immobilized, functionalized MWCNT-based electrochemical immunosensor on a gold electrode.
• Utilizing anti-AFB1 monoclonal antibodies (mAbs) for specific AFB1 capture and MWCNTs as signal amplifiers.
• Quantifying AFB1 using differential pulse voltammetry (DPV) based on reduced current signals.

Main Results:

• The developed immunosensor demonstrated excellent sensitivity with a limit of detection (LOD) of 0.021 ng/mL and a wide dynamic range (0.05-100 ng/mL).
• The sensor exhibited high selectivity, good stability over 7 days, and reusability, along with effective anti-interference capabilities against other mycotoxins.
• Practical application in fortified food samples (malt, lotus seed, hirudo) showed satisfactory recovery rates (92.08-104.62%).

Conclusions:

• The Nafion-MWCNT-based electrochemical immunosensor provides a highly sensitive, selective, and stable platform for AFB1 detection.
• This cost-effective and easy-to-construct sensor offers a promising solution for onsite food safety monitoring.
• The platform's adaptability suggests potential for detecting other mycotoxins in diverse food matrices.