The electrochemical redox behavior of Cu(II) has been investigated at glassy carbon electrode (GCE) in Britton-Robinson (BR) buffer as well as in a mixture of BR buffer and potassium chloride media. It is apparent that BR buffer can act as a supporting electrolyte and modify the electrochemical behavior of Cu(II) ion in aqueous medium. In BR buffer medium, Cu(II) undergoes one two-electrons redox process, while in a mixture of BR buffer and KCl media it follows two one-electron electrochemical reaction routes. Because of the formation of hydrogen bridge bond between the supporting electrolyte and GCE surface, the Cu(II) ion follows Cu(II)/Cu(0) electrochemical reaction path, while in presence of KCl such a hydrogen bridge bond is not formed and it undergoes successive Cu(II)/Cu(I) and Cu(I)/Cu(0) electrode reaction processes. Moreover, the linear variation of peak current with the square root of scan rate indicates that the electrochemical redox processes are diffusion controlled.

Electrochemical redox behavior of Cu(II) at different pH in Britton-Robinson (BR) buffer solution has been investigated using cyclic voltammetry at glassy carbon electrode (GCE). Cu(II) shows a cathodic peak and a hump-like peak, and an intense anodic peak at pH, 0.59, 1.59, 3.01 and 4.08. Although at lower pH (0.59 and 1.59) a cathodic peak, a hump and an anodic peak are observed, at higher pH (3.01 and 4.08) the hump-like cathodic peak disappeared. Cyclic voltammetry has also been used to observe the interaction of Cu(II) with cytosine in BR buffer solution at various pH. A reasonably strong interaction between Cu(II) and cytosine at different Cu(II)/cytosine molar ratio is observed at all the studied pH. However, maximum interaction occurs at 1:4 molar ratio at pH 4.08, this is perhaps the most suitable condition for Cu(II)-cytosine interaction.