Single-Molecule Graphene Junction Aflatoxin Sensors: Chemo-Physical Insights from Ab Initio Simulations

The aflatoxin B1 (AFB1) is a cancerogenic compound affecting the agri-food chain, endangering food safety and public health. Worldwide regulatory agencies establish strict limitations for the presence of AFB1 in crops. Current detection methods require bulky equipment, long measurement time, and skilled laboratory researchers, which make it challenging to measure the AFB1 in the whole food chain pervasively. In this field, molecular junctions represent an exciting alternative in the sensing application, providing a highly integrable device for the fast measurement of chemical compounds. Through ab initio simulation, this work investigates graphene junctions for detecting AFB1. The results show that applying a bias voltage of 1.2 V to a graphene layer permits varying the electrical current of the junction by more than 3 µA when the AFB1 is present. The obtained results motivate research on the integrability of the device in more complex sensing systems such as intelligent sensors and electronic noses.