Pyrrole-based sensor for AFB1 with graphene electrodes

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic mycotoxin with high health risk due to its widespread food contamination. This study investigates a pyrrole-based single-molecule junction with graphene electrodes for amperometric sensing of AFB1, to address the need for for rapid, sensitive, and field-deployable detection of AFB1. Density Functional Theory (DFT) simulations are employed to study the adsorption process of AFB1 on the polypyrrole molecular junction and its influence on the electronic transport properties. Structural optimization confirms that AFB1 binds stably to the polypyrrole which triggers charge redistribution within the system. This molecular attachment affects the conductive properties of the sensor, as reflected in its current-voltage (I-V) characteristics. The results indicate a clear change in electrical response upon AFB1 adsorption, supporting the sensor’s ability to detect even small amounts of the toxin through amperometric sensing. These findings show the potential of the proposed nanosensor for the detection of AFB1 at the molecular level. The combination of graphene electrodes and polypyrrole enhances stability and charge transport efficiency, paving the way for further experimental validation and real-world deployment.