A Flexible, Ultrasensitive, and Highly Selective Bi-Functional Acetone and Ethanol Gas Sensor

To date, most of the acetone and ethanol gas sensors suffer from common issues including low sensitivity, poor selectivity, and high energy consumption for practical applications. This work reports a flexible, ultrasensitive, and highly selective bi-functional acetone and ethanol gas sensor on a single chip based on molecular imprinted technology. A thin layer of graphene is deposited on a plastic substrate using spray coating between two gold electrodes. The gas sensing mechanism is based on the change in the electrical conductivity of graphene upon the adsorption and desorption of gas molecules. The sensors show linear response in the targeted range of 1-10 ppm of acetone and 130-210 ppm of ethanol. Additionally, the sensors exhibit a high sensitivity of 17.50/$\Omega$ ppm for acetone and 3.45/$\Omega$ ppm for ethanol. The limit of detection (LOD) was calculated to be 0.26 ppm and 78.76 ppm for acetone and ethanol, respectively. Moreover, the proposed sensors show high reproducibility and stability.