Self-assembled multilayer of alkyl graphene oxide for highly selective detection of copper(II) based on anodic stripping voltammetry

A novel graphene oxide multilayer with ordered structure was formed by self-assembly of alkyl functionalized graphene oxide on a metal substrate and showed specific electrochemical properties for the determination of copper(II) in solution using square wave anodic stripping voltammetry (SWASV). The ordered structure of the multilayer was evident from its regular X-ray patterns. Optimal electrochemical parameters, such as pH value, deposition potential and deposition time, were obtained for good SWASV performance. This alkyl chain functionalized graphene oxide film showed a high selectivity for the determination of Cu(II) in the presence of other metal ions. The detection limit of Cu(II) by the functional graphene oxide film was estimated to be 2.7 mu M, which is below the permitted limit of 20 mu M in drinking water given by the U.S. Environmental Protection Agency (EPA).