High-stability quartz crystal microbalance ammonia sensor utilizing graphene oxide isolation layer

This paper presents a new sensing structure to enhance the stability of a quartz crystal microbalance (QCM) ammonia sensor. The sensing structure consists of bi-layer films, in which graphene oxide (GO) film serves as an isolation layer between the electrode of the QCM and polyaniline (PANI) sensing film. The quality (Q) factor of the QCMs was measured with and without the GO isolation layer. The experiment results indicate that the quality factor of QCM with GO layer is about two times larger than that of the QCM without GO in the whole detection range, which means the introduction of GO isolation layer can effectively improve the quality factor of the QCM. The improvement of the Q factor is ascribed to the high elasticity modulus of GO isolation layer, which produced the suppression of the surface energy loss of the QCMs. The use of GO as isolation layer provides a simple way to realize high stability QCM sensors. (C) 2014 Elsevier B.V. All rights reserved.