▎ 摘　　要

A series of graphene oxide (GO) thin films for colorimetric sensing was fabricated by dip-coating technique. These films exhibited ultrafast response, good reversibility and obvious optical shifts within the visible range toward ethanol. Fourier transform infrared spectroscopy (FTIR) spectra confirmed that GO was successfully synthesized. Scanning electron microscope (SEM) and atomic force microscope (AFM) showed that the thickness of GO film can be modulated within 200 nm-275 nm. Ultraviolet-visible (UV-vis) spectrophotometer demonstrated that the spectra red shift with the increase of thickness of GO film. Dynamic study showed that absorption and desorption time was 120 ms and 80 ms, respectively. The selectivity of the GO sensor was studied by measuring the response time towards four kinds of vapor including EtOH, MeOH, H2O and NH3. The response time of EtOH was 120 ms and detection limit was 3.33 ppm. Colorimetric properties of GO film showed a promising application for fast and visualized sensing of ethanol with high performance. (C) 2018 Elsevier B.V. All rights reserved.