Investigating the acetone sensing capabilities of metal-organic framework-derived SnO2/ZnO nanocomposite

• SnO 2 /ZnO nanocomposites synthesized via Sn/Zn-MOF sacrificial template by hydrothermal method. • The Cr/Au IDE was fabricated and MOF derived SnO 2 /ZnO nanocomposites were deposited on IDE through e-beam evaporation and bi-layer lift-off process. • The fabricated portable sensor was exposed into various VOCs and studied its sensing characteristics. • The sensor exhibited excellent sensitivity and selectivity towards acetone at 250 °C. Recent advancements in the quantification of gas molecules in human breath have opened new avenues for diagnosing diseases like diabetes and cancer. These gas molecules act as biomarkers for specific diseases reflecting changes in metabolism caused by diseased cells. Acetone, in particular, is recognized as a potential biomarker for both diabetes and cancer. However, the existing acetone sensors suffer from low sensitivity, long response and recovery times, high cost, and high-power consumption owing to the factors like material property, sensing mechanism and operational conditions. This study explored the benefits of metal-organic frameworks (MOFs), including high surface area, porosity, structural tunability, and diverse signal transduction capabilities. The MOF-derived SnO 2 /ZnO nanocomposite was synthesized and analysed the material properties using TGA, XRD, FTIR, SEM/EDAX, HR-TEM, and XPS. These analyses confirmed the formation of the SnO 2 /ZnO nanocomposite with a uniform surface morphology and an average crystalline size of 14.4 nm. The sensing material was then coated by e-beam evaporation onto Cr/Au interdigitated electrode (IDE) fabricated via photolithography and a bi-layer lift-off process. The fabricated sensor demonstrated enhanced electrical conductivity at higher operating temperatures, attributed to the presence of n-n heterojunctions in the material. Notably, the sensor exhibited a remarkable response of 81.88 % towards 10 ppm of acetone at 250 °C, with excellent selectivity over other gases and a detection limit of 600 ppb. Additionally, the sensor showed a rapid response/recovery time of 17/19 s to acetone molecules. These results confirm the sensor's ability to detect and quantifying acetone molecules from human breath.