Au/SnO ₂ /reduced graphene oxide (RGO) nanocomposites have been successfully synthesized by a one-step method. The sample was characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectrometry to explore the formation mechanism. The gas sensing properties of the synthesized Au/SnO ₂ /RGO nanocomposites have been investigated, which revealed that Au nanoparticles obviously enhanced the sensitivity by comparing with the SnO ₂ /RGO nanocomposites and pure SnO ₂ . The Au/SnO ₂ /RGO nanocomposites showed higher response to ethanol than other VOCs. They also exhibited a wide linear detection range from 1 to 1000 ppm and high reproducibility to ethanol. Here, the sensing mechanism of the Au/SnO ₂ /RGO nanocomposites has also been discussed in detail.

Whispering gallery mode (WGM) resonators have attracted extensive attention and their unique characteristics have led to some remarkable achievements.