Preparation of Highly Dispersed Reduced Graphene Oxide Modified with Carboxymethyl Chitosan for Highly Sensitive Detection of Trace Cu(II) in Water

In this article, reduced graphene oxide (RGO)/carboxymethyl chitosan (CMC) composites (RGO/CMC) were synthesized by a hydrothermal method through in-situ reduction and modification of graphene oxide (GO) in the presence of CMC. An electrochemical sensor for the determination of Cu(II) by differential pulse anodic stripping voltammetry (DPASV) was constructed by an electrode modified with RGO/CMC. The fabricated electrochemical sensor shows a linear range of 0.02–1.2 μmol ̈L ́1, a detection limit of 3.25 nmol ̈L ́1 (S/N = 3) and a sensitivity of 130.75 μA ̈μmol ̈L ́1 ̈ cm ́2, indicating the sensor has an excellent detection performance for Cu(II).