Label-free electrochemical immunosensor for Ochratoxin a detection in coffee samples

Area of Science:

• Food Science
• Analytical Chemistry
• Biosensor Technology

Background:

• Ochratoxin A (OTA) is a toxic mycotoxin found in coffee, posing risks to human health and the economy.
• There is a need for rapid, on-site detection methods for OTA in food products.

Purpose of the Study:

• To develop a label-free impedimetric immunosensor for sensitive and selective Ochratoxin A detection.
• To evaluate the biosensor's performance for on-site coffee analysis.

Main Methods:

• Fabrication of a gold electrode biosensor modified with cysteamine and anti-OTA antibodies.
• Characterization using Atomic Force Microscopy and Raman Microspectroscopy.
• Performance evaluation using Electrochemical Impedance Spectroscopy.

Main Results:

• A linear response between impedance and OTA concentration (0.5–100 ng mL⁻¹) was observed.
• A low limit of detection (0.15 ng mL⁻¹) was achieved.
• The biosensor demonstrated high selectivity and no matrix interference in coffee samples.

Conclusions:

• The developed impedimetric immunosensor is a promising device for simple, sensitive, and on-site OTA detection.
• The biosensor's potential for miniaturization and rapid analysis supports its use in coffee quality control.
• This technology contributes to enhanced food safety and quality assurance in the coffee industry.