▎ 摘　　要

Tapered optical fibers coated with graphene and graphene oxide (GO) as the active layer for ethanol sensing were reported. The multimode optical fiber with 125 mu m diameter was tapered to 40 mu m diameter to enhance the sensitivity. Graphene and GO thin films were characterized using a scanning electron microscopy, Raman spectroscopy and ultraviolet-visible (UV-Vis) spectroscopy. The absorbance properties of the developed sensors increased when exposed to ethanol due to the change of light in the evanescent field. The sensing results indicated that the GO-coated sensor showed better performance with absorbance change of 80 % towards ethanol concentration of 5 % when compared to graphene-coated sensor with 40 % absorbance change towards ethanol with similar concentrations. The reliable response of the graphene and GO-coated on tapered fibers for detecting ethanol concentrations was achieved at room temperature.