Hierarchical Pt-decorated In₂O₃ microspheres with highly enhanced isoprene sensing properties

For advanced fibrosis, isoprene is a typical characteristic marker that could be used to quickly screen the population for chronic liver disease (CLD). To achieve trace detection of isoprene, different mol% Pt-decorated In₂O₃ and pure In₂O₃ samples were prepared with the commonly used hydrothermal method. The obtained characterization results show that the prepared Pt-decorated In₂O₃ (1 mol%) sample had Pt nanoparticles uniformly attached to the surface of porous hierarchical In₂O₃ nanosheets, and the specific surface area was 62.3 m²/g. Subsequently, these sensors based on Pt–In₂O₃ and pure In₂O₃ nanomaterials were prepared, and their response characteristics were studied. The results show that the response of 1 mol% Pt–In₂O₃ to isoprene gas was significantly enhanced, and the optimal working temperature was 200 °C. The response of 1 mol% Pt–In₂O₃ to 5 ppb and 5 ppm isoprene was approximately 3.2 times and 25.9 times that of pure In₂O₃, respectively. Meanwhile, the 1 mol% Pt-modified sample exhibited excellent selectivity for isoprene relative to other biomarkers (carbon monoxide, hydrogen, ethanol, and ammonia). The sensor shows good repeatability and long-term stability. Therefore, the developed 1 mol% Pt-decorated In₂O₃ was expected to be applied as a gas-sensitive material for breath isoprene, which could be suitable for large-scale CLD rapid breath detection.