▎ 摘　　要

We propose and theoretically investigate the physical properties of an alternative design of graphene gas sensor, composed of a nanoscaled gas-inert conducting wire between two graphene leads. The sensing mechanism is based on the conduction variation in the nanoscaled conducting wire as a result of a density-of-states change in the graphene leads via the orbital hybridization established between the graphene leads and the absorbed gas molecules. We use the coherent potential approximation to treat the disordered system resulting from the random gas molecule absorption and apply the Keldysh non-equilibrium Green's function method to calculate the transport properties. Compared with the conventional gas sensors that use graphene as the conducting wire, the one proposed here is superior, especially for charge-donor gases. Copyright (C) EPLA, 2011