Electrochemical Studies of Interactions Between Fe(II)/Fe(III) and Amino Acids Using Ferrocene-Modified Carbon Paste Electrode

Abstract

The electrochemical behavior of an Fe(II)/Fe(III) redox couple in the presence of various selected amino acids has been studied using ferrocene-modified carbon paste electrode at pH = 7.4. Because of Fe(II)/Fe(III) solubility issues at physiological pH, ferrocene was used as a source of iron. Anodic oxidation of iron (pH = 7.2) occurred at 0.356 V and cathodic oxidation at 0.231 V, both vs Ag|AgCl. Treatment of the voltammetric data showed that it was a purely diffusion-controlled reaction with the involvement of one electron. After addition of amino acids, potential shifts and current changes can be observed on the voltammograms. Cyclic voltammetry experiments revealed the capability of amino acids to change the electrochemical behavior of the Fe(II)/Fe(III) redox couple.

Keywords

• iron
• amino acid
• cyclic voltammetry
• ferrocene
• carbon paste electrode