Borophene as an electronic sensor for metronidazole drug: A computational study

The electronic sensitivity and reactivity of a B₃₆ borophene are scrutinized toward the metronidazole (ML) drug using density functional theory calculations. The drug is mainly adsorbed via its -NO₂ group on the edge of the B₃₆ borophene. In the gas phase, the adsorption energy and Gibbs free energy change are about -22.1 and -19.3 kcal/mol, respectively. Because of a large HOMO destabilization upon the ML adsorption, the HOMO-LUMO gap (E_g) of B₃₆ meaningfully decreases from 1.84 to 0.75 eV. It increases the electrical conductivity which creates an electrical signal. The signal is connected to the ML presence, indicating that the borophene may be a proper sensor for the ML detection. A short recovery time of 1.53 s is estimated for the ML desorption from the B₃₆ surface. Unlike the E_g, the Fermi level and work function of B₃₆ are not altered sensibly by the ML drug adsorption. The interaction of ML with the B₃₆ sheet weakens in the water solvent.