▎ 摘　　要

In lung cancer, primary diagnosis is quite essential to guarantee human health. In this work, the capability of gamma-graphyne and twin-graphene sheets to detect typical breath gases such as benzene, styrene, aniline, and o-toluidine is studied based on density functional theory. The results indicate that these gases are physisorbed on gamma-graphyne and twin-graphene. Because of relatively low gas binding strength between gases and gamma-graphyne and twin-graphene, these sheets can be proper for the practical gas sensors with a fast recovery rate. Both gamma-graphyne and twin-graphene have semiconducting properties before and after gas adsorption. Adsorption of the gases decreases the energy band gap, and increases the electric dipole moment of gamma-graphyne and twin-graphene. The electronic properties of twin-graphene are more sensitive than that of gamma-graphyne to the presence of the considered gases. Hence, twin-graphene can be desirable and promising material for sensing typical breath gases to diagnose lung cancer. (C) 2019 Elsevier B.V. All rights reserved.