Utilizing a nanocomposite consisting of zinc ferrite, copper oxide, and gold nanoparticles in the fabrication of a metformin electrochemical sensor supported on a glassy carbon electrode

The conception and development of a new electrochemical sensor is reported for the detection of metformin (MET). Zinc ferrite and copper oxide nanostructure (ZnFe₂O₄-CuO) and gold nanoparticles (AuNPs) have been used to prepare a nanocomposite in modifying a glassy carbon electrode (GCE). The unique ZnFe₂O₄-CuO/Au nanocomposite was applied as a sensor for the determination of traces of MET by some electroanalytical techniques. Experimental parameters affecting the results were investigated and optimized. Under the optimum conditions and at a working potential of 0.85 V (vs. Ag/AgCl/3.0 M KCl), the sensor response is linear in the MET range of 1.0 nmol L⁻¹ to 1.0 μmol L⁻¹ MET. The limit of detection (LOD) is 0.3 nmol L⁻¹ (at an S/N ratio of 3) and the sensitivity is 1.13 μA μmol L⁻¹ cm⁻². The sensor was applied to the determination of MET in real samples where it gave acceptable results.