Facile fabrication of high-performance QCM humidity sensor based on layer-by-layer self-assembled polyaniline/graphene oxide nanocomposite film

This paper demonstrates a layer-by-layer self-assembled polyaniline (PANI)/graphene oxide (GO) film on quartz crystal microbalance (QCM) for humidity sensing. The morphological and compositional properties of PANI/GO composite films were examined by means of SEM, XRD and FT-IR. The humidity sensing properties of the PANI/GO nanocomposite-based QCM sensor were investigated by exposing to a broad range of 0-97%RH. The experimental results showed that the presented PANI/GO nanocomposite sensor has a high sensitivity, a good repeatability and fast response/recovery characteristics, which surpasses the previous reported counterparts. Moreover, the underlying humidity sensing mechanism of the PANI/GO-based QCM sensor was discussed by using Langmuir adsorption model. This work highlights the unique advantage of layer-by-layer self-assembled route for QCM sensor fabrication.