Graphene-based sensor of aflatoxin molecule: a simulation-based investigation

For some years now the unique electronic properties of graphene have attracted interest in this material. There are many research areas that involve it, from high-speed electronics to sensors. The latter together with molecular electronics promise the creation of graphene sensors capable of identifying individual molecules. This is the sector in which this thesis work belongs, in which graphene is analyzed as a possible sensor for the aflatoxin molecule. In the first part the main characteristics of graphene are reviewed, with its physical structure, the particular electronic band structure, the transport behavior, the density of the states, its finite-dimensional structures, the presence of defects and the doping. The aflatoxin molecule is described with its peculiarities and the reasons for its danger. Finally, the characteristics of the adsorption process and the use of graphene as a sensor are indicated, selecting some related research and works. In the second part, graphene is investigated as a possible sensor for the aflatoxin molecule. Through simulations of the Quantum ATK software package, the adsorption of the molecule on graphene is first analyzed by investigating the adsorption energy for various geometric configurations and then graphene is examined as a sensor by analyzing its sensitivity and selectivity. The result obtained is that graphene has a good sensitivity with respect to aflatoxin, identifiable through a variation of the current in the presence and absence of the molecule, but it is not very selective, as a very similar behavior is observed with some other molecules.