Biosensors-based polypyrrole/metal-organic framework core-shell for mycotoxins detection.

Area of Science:

• * Materials Science: Development of novel core-shell nanostructures for advanced sensor applications.
• * Analytical Chemistry: Electrochemical detection of mycotoxins in complex matrices.

Background:

• * Ochratoxin A (OTA) is a prevalent, carcinogenic mycotoxin found in food and beverages, posing significant health risks.
• * Current detection methods like HPLC are cumbersome, while electrochemical aptasensors require complex fabrication and offer limited output.
• * A need exists for sensitive, selective, rapid, and scalable biosensing platforms for mycotoxin detection.

Purpose of the Study:

• * To develop a highly sensitive and selective electrochemical biosensor for ultra-trace Ochratoxin A detection.
• * To create a stable, core-shell nanostructure-based platform for simplified mycotoxin analysis.
• * To enable direct detection of OTA in food matrices without prior sample treatment.

Main Methods:

• * Fabrication of a core-shell nanostructure using conductive polypyrrole (Ppy) and Zirconium nanosized metal-organic framework (Zr-NMOF).
• * Immobilization of DNA aptamers onto the positively charged Ppy/Zr-NMOF nanostructure via electrostatic interaction.
• * Electrochemical detection of OTA based on the synergistic effect of Ppy and Zr-NMOF on electrical properties.

Main Results:

• * Demonstrated ultra-trace detection of OTA with a limit of detection of 0.24 pM (0.1 ng/L).
• * Achieved high selectivity for OTA over Ochratoxin B (OTB) and a wide dynamic linear range.
• * Successfully detected OTA directly in red wine with high recovery, comparable to standard methods.

Conclusions:

• * Presented the first Ppy/Zr-NMOF/DNA biosensor with enhanced electrical and stable properties for mycotoxin detection.
• * The developed bioelectronic interface allows sensitive detection of mycotoxins at concentrations as low as 0.1 ng/L.
• * This innovative approach is adaptable for detecting various contaminants by modifying aptamers, offering a versatile platform for food safety.