▎ 摘　　要

Exhaled acetone in the non-invasive diagnosis of type I diabetes is one of the representative biomarkers. In this work, the Ag nanoparticles (NPs) modified Fe3O4/rGO composites was synthesized through a simple hydro thermal reaction, which could be a potential acetone sensor for painless and rapid breathing analysis. Through SEM and TEM, it was found that Ag nanoparticles were uniformly distributed on the surface of rGO sheets embedded in rod-shaped Fe3O4. Compared with the matrix material, the Ag/Fe3O4/rGO sensor shows good selectivity to acetone, and the cross-response to interfering gases (methane, toluene, ammonia, ethanol) is negligible. Meanwhile, the Ag0.1/Fe3O4/rGO sensor shows an ultra-high response of 35.81-50 ppm acetone at 220 degrees C, which is 2.5 times higher than that of pure Fe3O4/rGO. The improvement of Ag/Fe3O4/rGO nanomaterial in acetone sensing properties comes from the chemical and electronic sensitization effects of Ag nanoparticles, and this nanostructure generates more oxygen species and active sites, and improves the gas response. As a result, Ag0.1/Fe3O4/rGO has a good response and selectivity to acetone vapor, indicating its potential application in breath acetone analysis.