▎ 摘　　要

NOVELTY - Electrochemical sensor has a working electrode, a counter electrode and a reference electrode, where the working electrode, the counter electrode and the reference electrode are respectively connected to the electrochemical workstation through wires, and the working electrode is a composite electrode modified by a nitrogen-doped reduced graphene oxide nanocomposite material. USE - The electrochemical sensor is used for simultaneous trace detection of multiple ions, preferably four heavy metal ions of zinc ion, cadmium ion, tin ion and lead ion in actual water samples. ADVANTAGE - The sensor realizes the simultaneous trace detection of four heavy metal ions of zinc ion, cadmium ion, tin ion and lead ion, and ensures rapid detection and high sensitivity. The preparation method of the electrochemical sensor is simple, easy to operate and economical.