Molybdenum disulfide catalyzed tungsten oxide for on-chip acetone sensing

Acetone sensing is critical for acetone leak detection and holds a great promise for the noninvasive diagnosis of diabetes. It is thus highly desirable to develop a wearable acetone sensor that has low cost, miniature size, sub-ppm detection limit, great selectivity, as well as low operating temperature. In this work, we demonstrate a cost-effective on-chip acetone sensor with excellent sensing performances at 200 °C using molybdenum disulfide (MoS₂) catalyzed tungsten oxide (WO₃). The WO₃ based acetone sensors are first optimized via combined mesoscopic nanostructuring and silicon doping. Under the same testing conditions, our optimized mesoporous silicon doped WO₃ [Si:WO₃(meso)] sensor shows 2.5 times better sensitivity with ∼1000 times smaller active device area than the state-of-art WO₃ based acetone sensor. Next, MoS₂ is introduced to catalyze the acetone sensing reactions for Si:WO₃(meso), which reduces the operating temperature by 100 °C while retaining its high sensing performances. Our miniaturized acetone sensor may serve as a wearable acetone detector for noninvasive diabetes monitoring or acetone leakage detection. Moreover, our work demonstrates that MoS₂ can be a promising nonprecious catalyst for catalytic sensing applications.