A quartz crystal microbalance (QCM) based system has been developed for the selective analysis of Cu2- ions in aqueous solution. The crystal is coated with a thin film of poly(acryloyl morpholine) which selectively chelates Cu2- over other M2+ ions. A novel coating procedure involving the preparation of sulphur terminated polymer chains followed by self-assembly onto the gold was used. The sensor could be used over the concentration range between 0.5 and 70 ppm. The method shows promise although further optimisation of the coating procedures and ligand loading are needed to extend the concentration range and improve the speed of response.