▎ 摘　　要

Graphene has a large specific surface area and a high electron traction rate, so it can be widely used in gas-sensing devices. To analyze the gas-sensing properties of graphene, the non-linear electromagnetic field response (NLEFR) of graphene before and after ammonia adsorption is studied in this paper. Under DC bias, the change rate of output harmonic power of the multilayer graphene-sensing characteristic analysis device is 30% higher than that of DC resistance. The results of this work indicate that a new graphene-based sensor can be developed using its NLEFR.