Sensitive Breath Acetone Detection Based on α-Fe2O3 Nanoparticles Modified WO3 Nanoplate Heterojunctions

Acetone plays a critical role in environmental protection and human healthcare, thus necessitating sensitive and selective detection. In this regard, a resistive microelectromechanical system (MEMS) acetone sensor featuring a sensing layer of
$\alpha $
-Fe2O3 nanoparticles modified tungsten trioxide (WO3) nanoplates is utilized in this work. After optimizing the composition proportion and operating temperature, the Fe/W:0.2 sensor delivered a wide detection range (0.05–80 ppm), and an approximately sevenfold higher response of 40.6 toward 10 ppm acetone at
$217~^{\circ }$
C than pure WO3 analog. In addition, a limit of detection (LoD) of 50 ppb was achieved, which ranks among the lowest cases thus far. Together with excellent repeatability, selectivity, and long-term stability, the sensor also showed a humidity-enhanced response. This work offers an alternative strategy to realize trace acetone detection within high-humidity conditions and showcases a huge application potential in exhaled breath-involving diabetes monitoring in the future.