Chemical-sensing of Amphetamine drug by inorganic AlN nano-cage: A DFT/TDDFT study

Abstract

The electronic sensitivity and reactivity of a pristine Si, Ga and Ge-doped Al24N24 nanocluster with AM drug were investigated using density functional theory (DFT). With adsorption energy of approximately −35.5 kcal/mol, AM drug was found to be adsorbed chemically on pristine Al24N24 nanocluster through its N-head and to exert no effects on the electrical conductivity of this cluster. Substituting Si, Ga and Ge atoms for Al atoms in Al24N24 nanocluster significantly elevates the reactivity of Al24N24 nanocluster respectively at predicted adsorption energies of approximately −24.05, −11.75 and −34.38 kcal/mol. Significant HOMO destabilization in Si-AlN nanocluster through AM drug adsorption increases the electrical conductivity of Si-AlN nanocluster while generating electrical signals and reduces its Eg from 2.17 to 1.35 eV. These signals are associated with the presence of AM drug in the environment. Therefore Si-doped Al24N24 nanocluster is found to constitute a promising electronic AM drug sensor. AM drug adsorption increases electron emission from the surface of this sensor and significantly reduces its work function. Significant effects of AM drug adsorption on the Fermi levels and work function of Si-AlN nanocluster make it an Φ–type candidate for AM drug sensors.