N-doped reduced graphene oxide /MnO2 nanocomposite for electrochemical detection of Hg2+ by square wave stripping voltammetry

In this paper, N-doped reduced graphene oxide and MnO₂ nanocomposite (N-RGO/MnO₂) was synthesized via hydrothermal method, which was used to modify the glass carbon electrode (GCE) for electrochemical detection of Hg²⁺. p-phenylenediamine was used as the nitrogen source and "bridging" molecule between MnO₂ and RGO. The electrochemical sensing performance towards Hg²⁺ was evaluated by square wave anodic stripping voltammetry method. The presence of N-RGO/MnO₂ nanocomposite has enhanced the electrochemical performance of the GCE toward Hg²⁺. The N-RGO/MnO₂ nanocomposite modified electrode was found to have a good sensitivity toward Hg²⁺ and the favorable sensitivity (72.16 μA/μM) and LOD (0.0414 nM) for Hg²⁺ were achieved under the optimized conditions. Moreover, the modified electrode possessed a good stability and reproducibility. The excellent performance can be attributed to the characteristic nanostructure and N-doping property of the N-RGO/MnO₂ nanocomposite. This electrochemical sensing strategy is expected to enrich the application field of electrochemical determination and does good to the issue of environment pollution analysis.