Rapid Electrochemical Sensing of Zn(II) Using MesoporousMnO2@N-Graphene Composites

Detecting and quantifying the concentration of Zn $^{{2}+}$ provide the opportunity to balance the beneficial and harmful impacts on living systems. Herein, we developed a sensitive electrochemical sensor for Zn $^{{2}+}$ detection based on manganese dioxide@nitrogen-doped graphene (MnO2@N-graphene), which was synthesized by a one-step hydrothermal process. MnO2 with excellent adsorption capacity and N-graphene with precise tuning of the charge carrier mobility achieve high conductivity. By integrating the merits of MnO2 with N-graphene, the as-developed MnO2@N-graphene-based sensor was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimal conditions, the designed sensor displayed excellent performance for the detection of Zn $^{{2}+}$ over the range of 2.00 $\times \,\,10^{-{7}}$ –1.80 $\times \,\,10^{-{4}}$ M, with a detection limit of 2.20 $\times \,\,10^{-{8}}$ M. In addition, the proposed sensor platform showed good reproducibility. Furthermore, the feasibility of its applications has also been demonstrated in the practical sample analysis with a recovery of 93.4%–103%, offering a new avenue for detecting other heavy metal ions.