Aqueous ethanol detection using a fiber-optic sensor based on Fresnel reflection

We propose a novel aqueous ethanol fiber-optic sensor which is based on Fresnel reflection. It is functionalized with a thin-layer of an ethanol-sensitive graphene oxide (GO) coating on a single mode optical fiber end. The trace of ethanol concentration was measured by the variations in Fresnel reflection intensity and the optical properties of graphene oxide. The sensor output was obtained successfully in response to aqueous ethanol concentration from 20% to 100%. The fiber end with GO film exhibited real- time and remote measurement of ethanol concentration with high precision.