Acetone-sensing properties of doped ZnO nanoparticles for breath-analyzer applications

We report the effects of various dopants (Al, Co, and Cu) on the acetone-sensing properties of ZnO nanoparticles (NPs) for breath-analyzer applications. Among the different sensing materials, the Al-doped ZnO NPs exhibited the highest sensitivity toward 1 ppm acetone, with a maximum response of 11.8 at 500 °C. This improved sensing performance was related to deep donor-level defects caused by double oxygen vacancies in the Al-doped ZnO NPs, as confirmed by photoluminescence spectra. Thus, Al was a more effective dopant than Cu and Co for enhancing the sensing properties of ZnO NPs for the detection of acetone. We achieved selective detection of 0.5 ppm acetone in air using the Al-doped ZnO NPs incorporated into a miniaturized gas chromatograph (GC). The results indicate that the miniaturized GC integrated with the Al-doped ZnO NPs can be utilized for an acetone breath analyzer.