▎ 摘　　要

The detection of 2-butanone in the human breath might become a promising new method for non-invasive diagnosis and painless monitoring of Helicobacter pylori. A portable 2-butanone sensor was developed by using the graphene or ZnO nanorod electrode. Both electrodes were characterized by SEM and XRD. The ZnO nanorod arrays has a wurtzite structure with a diameter of 30 similar to 100 nm while the graphene exhibits the hexagonal flakelike structure. The sensing results confirmed that the ZnO nanorod electrode shows higher sensitivity but slower response and recovery time toward 2-butanone compared to the graphene electrode. The high gas flow rate of 400 sccm and operating temperature of 200 degrees C are necessary to enhance the response of ZnO nanorod arrays. Both electrodes possess good repeatability for 2-butanone detection. The sensor based on the ZnO nanorod electrode shows a high selectivity to 2-butanone over methanol, ethanol, acetone, and benzene. The gas sensing mechanism is also discussed.