Graphene-derived materials are an excellent electrode for electrochemical detection of heavy metals. In this study, a MnO2/ graphene supported on Ni foam electrode was prepared via ultrasonic impregnation and electrochemical deposition. The resulting electrode was used to detect Pb(II) in the aquatic environment. The graphene and MnO2 deposited on the Ni foam not only improved active surface area, but also promoted the electron transfer. The electrochemical performance towards Pb(II) was evaluated by cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The prepared electrode exhibited lower limit of detection (LOD, 0.2 μM (S/N = 3)) and good sensitivity (59.9 μAμM−1) for Pb(II) detection. Moreover, the prepared electrodes showed good stability and reproducibility. This excellent performance can be attributed to the strong adhesion force between graphene and MnO2, which provides compact structures for the enhancement of the mechanical stability. Thus, these combined results provide some technical considerations and scientific insights for the detection of heavy metal ions using composite electrodes.

MnO2graphene supported on Ni foam: an advanced electrode for electrochemical detection of Pb(II)
    Abstract
    1 Introduction
    2 Experiment sections
        2.1 Fabrication of the MnO2grapheneNi electrodes
        2.2 Characterization of the MnO2grapheneNi electrodes
        2.3 The electrochemical measurements
    3 Results and discussion
        3.1 The properties of MnO2grapheneNi electrodes
        3.2 Electrochemical analysis
        3.3 Real sample analysis
    4 Conclusions
    Anchor 13
    Acknowledgements 
    References

• Rui Liu(Center of Pharmaceutical Engineering and Technology, School of Pharmacy, Harbin University of Commerce, Harbin 150076, People’s Republic of China)
• Chao‑Jun Zhang(Center of Pharmaceutical Engineering and Technology, School of Pharmacy, Harbin University of Commerce, Harbin 150076, People’s Republic of China)
• Xue Han(Center of Pharmaceutical Engineering and Technology, School of Pharmacy, Harbin University of Commerce, Harbin 150076, People’s Republic of China)
• Tian‑Heng Wu(Center of Pharmaceutical Engineering and Technology, School of Pharmacy, Harbin University of Commerce, Harbin 150076, People’s Republic of China)
• Ri‑Jia Liu(Center of Pharmaceutical Engineering and Technology, School of Pharmacy, Harbin University of Commerce, Harbin 150076, People’s Republic of China)
• Yuan Sun(Center of Pharmaceutical Engineering and Technology, School of Pharmacy, Harbin University of Commerce, Harbin 150076, People’s Republic of China)
• Shuang Jin(College of Pharmacy, Heilongjiang University of Chinese Medicine, Harbin 150040, People’s Republic of China)