Highly selective real-time detection of breathacetone by using ZnO quantum dots with a miniaturized gas chromatographic column

In this study, we developed a breath acetone analyzer based on a miniaturized gas chromatography (GC) column integrated with ZnO quantum dots (QDs); this analyzer is capable of analyzing a wide range of breath acetone concentrations within 2 min using a small volume (1 ml) of human breath without pre-concentration. The average size of the ZnO QDs, which were synthesized by a wet chemical method, was approximately 6 nm. The developed analyzer could detect acetone concentrations as low as 0.1 ppm. The response of the ZnO QDs increased with increasing acetone concentration and was strongly correlated with the concentration (R2 = 0.9915). The miniaturized GC column effectively separated acetone from the breath. In addition, a preliminary testing of the breath acetone analyzer was performed through the breath analysis of volunteers who were on ketogenic and normal diets. The results showed that the acetone content in the breath of the volunteer who was on a ketogenic diet for three days was 1.2 ppm.