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

The aflatoxin Bl (AFBl) 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 AFB 1 in crops. Current detection methods require bulky equipment, long measurement time, and skilled laboratory researchers, which make it challenging to measure the AFB 1 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 AFBI. 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
$3\mu \mathrm{A}$
when the AFBI 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.