Graphene-coated quartz crystal microbalance for detection of volatile organic compounds at room temperature

The detection of volatile organic compounds (VOCs) at room temperature with rapid response and recovery is important for early explosive alarm. Herein, we demonstrate significantly enhanced VOC-sensing properties of quartz crystal microbalance (QCM) coated with monolayer graphene film. The monolayer graphene was firstly synthesized by the chemical vapour deposition (CVD) method on Cu foil and then transferred to the gold electrode of the QCM for VOC-sensing application. The gas-sensing properties of the graphene-coated QCM sensor were examined at room temperature for various concentrations of numerous VOCs, including butanol, isopropanol, acetone, and ethanol. The results revealed that the graphene-coated QCM sensor exhibits the best performance with ethanol gas. The gas-sensing mechanism of the graphene-coated QCM sensor was attributed to the adsorption and desorption of VOC molecules on the defect sites of graphene sheet.