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.