Abstract: The paper presents a new type of modified glassy carbon paste electrode with different Co- ferrites. First part of this work was the preparation of ferrites by five different methods such as hydrothermal, ultrasound and microwave-assisted hydrothermal, mechanochemical and sol-gel synthesis. Ferrite nanoparticles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). They were used for preparation new modified glassy carbon paste electrode (CoFeMGCPE). The electrode was used for determination of nanomolar level of copper ions in waste waters using electrochemical methods such as differential pulse anodic stripping voltammetry, DPASV. A significant increase in current was achieved at the modified electrode in comparison with the bare glassy carbon paste electrode. Detection limit for the proposed electrode was 30nM Cu when percentage of modifier was 3%, pH 4.5, deposition potential -0.3 V and deposition time 4min. This electrode was successfully applied for determination of copper ions in waste water without any pre-treatment.