Pt-Sensitized In2O3 Nanotubes for Sensitive Acetone Monitoring

Detecting 1 ppm acetone at high humidity is essential for a noninvasive diabetes diagnosis. Metal oxide gas sensors are a promising technology to achieve high sensitivity acetone monitoring. Here, we fabricated Pt-sensitized In2O3 nanotubes, and the gas-sensing performance was tested against eight gases. The fiber structure contributes to the uniform dispersion of Pt onto the In2O3. Pt-sensitized In2O3 nanotubes have lower optimal operating temperatures and higher sensitivity and selectivity than those of the In2O3 nanotubes. The 0.75 wt % Pt-In2O3 sensor has the maximum sensitivity (113) to 10 ppm acetone at 300 °C; the response and response time to 1 ppm acetone are 19.9 and 10 s, respectively. The response to 1 ppm acetone still has 9.83 at the relative humidity of 83%. It also has a low limit of detection (8.4 ppb) and good long-term stability (30 days). These results illustrate that Pt-sensitized In2O3 nanotubes have the potential for a noninvasive diabetes diagnosis.