Advanced yolk-shell Pt@In2O3 nanoreactor: Achieving selective and ppb-level acetone detection

Abstract

Acetone is commonly used in industry and laboratories but can harm human organs at high concentrations. It also serves as a biomarker for fat metabolism. The accurate detection of acetone using chemiresistive gas sensors holds great promise for applications in human exhaled breath analysis. It remains a hurdle to overcoming challenges with metal oxide-based sensors in detecting acetone selectively at parts per billion (ppb) levels, especially in high-humidity environments. We synthesised a Pt@In₂O₃ yolk-shell nanoreactor that ensures gas sensing performance while protecting noble metal nanoparticles from oxidation. It has a 20-ppb detection limit, a good response of 5.13 at 1.8 ppm under a high relative humidity of 90 %, and outstanding selectivity for acetone. Chemical state analyses and first-principles calculations reveal that the nanoreactor has abundant oxygen vacancy and strong acetone adsorption, facilitating enhanced charge transfer during sensing. Exhaled breath tests confirm that our sensors can differentiate individuals with abnormal respiratory acetone levels. Our study opens a new path for developing high-performance gas-sensitive materials and structures for a wide range of applications.