MOF-Derived ZnO Thin Films with Uniformly Dispersed Pt Nanoparticles for High-Performance Acetone Detection

Acetone is a vital biomarker for noninvasive diagnosis of diabetes and metabolic disorders. However, its low concentration in exhaled breath and interference from other volatile compounds make its detection highly challenging. High surface area, uniform nanostructure, and precise catalytic surface decoration are key factors for achieving high-performance acetone sensors. This work reports the synthesis of platinum (Pt)-functionalized zinc oxide (ZnO) thin films, derived from metal-organic frameworks (MOFs), engineered to enable highly sensitive and selective detection of acetone at low concentrations. At first, DC sputtering was used to fabricate a thin film of compact ZnO. Then a simple solution approach was used to grow the Zeolitic Imidazolate Framework-8 (ZIF-8) in situ on sputtered ZnO. ZIF-8 was then transformed into a porous ZnO (D.ZnO) framework by heat treatment at 600 °C. Finally, D.ZnO surfaces were sputtered with varying thicknesses of Pt nanoparticles to optimize sensor performance. The optimized sensor exhibited outstanding acetone sensing performance with a low detection limit of 0.5 ppm (<i>S</i> = 55%), excellent long-term stability for 90 days, and good selectivity.