Ultrasensitive acetone gas sensor can distinguish the diabetic state of people and its high performance analysis by first-principles calculation

Detecting the acetone in human exhaled breath sensitively and selectively plays an important role in the noninvasive diagnosis of diabetes. However, obtaining a reliable response to ppb level acetone in exhaled breath directly is still a big challenge. Here, an ultrasensitive acetone gas sensor based on p-Rh2O3-n-ZnO porous heterostructure has been fabricated. The detection limit of the sensor reaches to 50 ppb. The sensor exhibits well repeatability, selectivity and linear response. A good linear relationship between the response and ambient relative humidity is observed. Without removing the water vapor of the exhaled gas, it can distinguish the acetone concentration of the diabetic patients from that of healthy people, implying that the sensor could be used in the diagnosis of diabetes. The synergistic effect of p-Rh2O3-n-ZnO porous heterostructure makes the sensor own ultrasensitive detecting ability towards acetone. Theoretical models have been built by first-principles calculation to reveal the possible reasons for its ultrasensitivity. It should be pointed out that the much lower adsorption energy (- 1.03 eV) of the acetone molecule on Rh2O3 may be the chief cause of the lower detection limit of the sensor.