▎ 摘　　要

Ethanol is detected by graphene sheet, and it is found that the resistance change is proportional to the ethanol concentration. The dynamic response of the evaporation is traced, showing longer recovery time for higher ethanol concentrations. The influence of the residual adsorbed molecules on the graphene sheet was also studied, and it was found that the resistance change is negatively proportional to the initial resistance of the graphene sheet corresponding to the effective surface area. The influence of the structure defects on the response resistance is also studied, and it was found that the structure defects enhance the resistance change. These investigations suggest a better way to extract a reliable signal for physical adsorption based material detection.