Determination of copper ions in foodstuff products with a newly modified potentiometric carbon paste electrode based on a novel nano-sensing layer

In the present study, a novel nano-layer sensing materials for the fabrication of a newly modified potentiometric carbon paste electrode was introduced. Its sensing layer was prepared with the incorporation of 1-(3-imino-4-hydroxophenyl-azo-4 nitrobenzene) isonicotinohydrazide "as an efficient ionophore" into the matrix consisting of graphite powder, synthesized graphene nanosheets, synthesized CdO nanowires, and diphenylacetylene (a typical molecular wire as the conductive binder). The suggested nanocomposite carbon paste electrode gave a Nernstian behavior in the linear range of 3.50 x 10(-9) to 1.00 x 10(-2) M with the detection limit of 1.44 x 10(-9) M. For investigation of the electrochemical behavior of Cu2+ at the surface of the unmodified and modified electrodes, the differential pulse voltametric method was used. The proposed sensor was successfully applied in the determination of copper ions in some foodstuff real samples with satisfactory results.