Rapid Electrochemical Sensing of Zn(II) Using Mesoporous MnO₂@Nitrogen-Doped Graphene Composites

Detecting and quantifying the concentration of Zn ²⁺ provide the opportunity to balance the beneficial and harmful impacts in living systems. Herein, we developed a sensitive electrochemical sensor for Zn ²⁺ detection based on manganese dioxide@nitrogen-doped graphene (MnO ₂ @N-graphene), which was synthesized by one-step hydrothermal process. MnO ₂ with excellent adsorption capacity, and N-graphene with precise tuning of the charge carrier mobility achieve high conductivity. By integrating the merits of MnO ₂ with N-graphene, the as-developed MnO ₂ @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 2.00×10 ^-7 to 1.80×10 ^-4 M, with a detection limit of 2.20×10 ^-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 recovery of 93.4% to 103%, offering a new avenue for detecting other heavy metal ions.