Abstract: An electrochemical sensor for Cu(II) based on ion-imprinted polymers was prepared by combining surface imprinting with electrochemical polymerization deposition. The sensor was modified by ion-imprinted magnetic carbon nanospheres with a specific selectivity and sensitivity for Cu(II). The morphology and structure of the materials were characterized and analyzed. Sensors with the imprinted electrode had a stronger selectivity and higher sensitivity towards Cu(II) compared with their original counterparts. Within relative concentrations of Cu(II) from 10⁻⁶ to 10⁻¹⁰ mol L⁻¹, the detection limit of the sensor was as low as 5.138×10⁻¹⁶ mol L⁻¹ (S/N=3). The sensor is resistant to interference, and has good reproducibility, and stability, making it excellent for the electrochemical detection of metal ions.