Single-atom Pt anchored In ₂ O ₃ nanorods for sensitive acetone detection using early fire warning

The development of high-performance gas sensors is crucial for applications in environmental monitoring, public safety, and healthcare. However, existing analytical techniques are often limited by high costs and operational complexity. In2O3 semiconductors exhibit great potential, while their practical application is hindered by inherent issues such as sensitivity and selectivity. Herein, we synthesized In2O3 with oxygen vacancies (In2O3-L) and anchored Pt single atoms, enabling real-time detection of low-concentration acetone. The In2O3-L-Pt sensor demonstrated a 5-fold improvement in response to 20 ppm acetone at 220 °C compared to In2O3, exhibiting rapid response/recovery time (2/30 s), ultra-low theoretical detection limits, excellent selectivity, and outstanding long-term stability. Experimental and theoretical results indicated that Pt single atoms enhanced adsorption and reduced activation energy barrier. Importantly, the Pt induced an internal electric field, increasing the thickness of the electron depletion layer (EDL), thereby amplifying the electrical response. This work demonstrates the potential of single-atom engineering to overcome the limitations of metal oxide sensors and presentes a new approach for designing next-generation portable sensing devices. Moreover, the sensor demonstrates practical application potential, as shown in simulated automotive fire-warning scenarios.