Fabrication and electrochemical study of [Ru(NH₃ )₆]³⁺/Nafion Ⓡ modified electrodes for the determination of trace amounts of Pb, Cd, and Zn via anodic stripping voltammetry

In this study, [Ru(NH₃ )₆]³⁺/Nafion Ⓡ modified electrodes were fabricated via the drop coating technique and were used for the determination of Lead (Pb), Cadmium (Cd), and Zinc (Zn) in trace heavy metal amounts using Anodic Stripping Voltammetry (ASV). The mediator concentration in the coating solution was varied at 5 mg, 10 mg, and 15 mg. The coating solution was drop-coated onto the surface of indium tin oxide (ITO) coated glass substrates and the fabricated electrodes were air dried at ambient temperature for about 12 hours. The fabricated electrodes were used to detect varying concentrations of Pb, Cd and Zn. ASV results showed that as the mediator concentration increases, the reduction current of the heavy metals increases as well. Also the heavy metal concentration and reduction current exhibited a linear relationship. The Pearson correlation values obtained for Pb and Cd using ASV and AAS were close to 1.0 indicating a strong positive linear relationship between the two variables. Zn has a relatively lower correlation value compared to Pb and Cd. The minimum heavy metal concentration that can be detected by the fabricated electrodes is 0.5 ppm