Room temperature ZnO/NiO heterostructure sensing response: A breath biomarker sensor

Breath biomarker detection has the great potential to enhance clinical diagnostics by monitoring health factors in a non-invasive manner and facilitating referrals. Room temperature non-invasive metal oxide semiconductor-based sensors play a prominent role in ailment detection. In this background, this work presents the acetone sensing characteristics of ZnO/NiO nanocomposites of five different ratios (0/1, 0.25/0.75, 0.50/0.50, 0.75/0.25 & 1/0) prepared via the electrospinning process. The electrospun nanocomposite revealed multijunction morphological features with interconnected grains. The structural studies confirmed the hexagonal phase of ZnO and the cubic phase of NiO with predominant (0002) and (2000) planes, respectively. Among the various ratios of ZnO/NiO nanocomposites, the ratio of 0.25 Ni2+ and 0.75 Zn2+ heterostructures exhibited a maximum response of S = 6.06 towards 100 ppm of acetone (CH3-CO-CH3) at room temperature. Response/retrieval times were found to be 28 and 34 s towards 100 ppm of acetone. The limit of detection of 1 ppm with fast transient characteristics is an encouraging factor to be considered for using the same for exhaling analysis.