Studies on the electrochemical behavior of cytochrome c and its interaction with DNA at a Co/GC ion implantation modified electrode

Abstract

The electrochemical behavior of cytochrome c (cyt c) and its interaction with DNA at a Co/glassy carbon (GC) ion implantation modified electrode were studied by linear sweep and cyclic voltammetry. In 0.005 mol dm⁻³ Tris–0.05 mol dm⁻³ NaCl buffer solution (pH = 7.10), a sensitive reduction derivative peak of cyt c was obtained by linear sweep voltammetry. The peak potential was 0.032 V (SCE). The peak current was proportional to the concentration of cyt c. The electrode process was quasi-reversible with adsorption. The electrode reaction rate constant k and the electron transfer coefficient α of cyt c were 4.42 s⁻¹ and 0.47, respectively. AES and XPS experiments showed that Co was implanted into the surface of the GC electrode (GCE). The implanted Co formed Co–C, which catalyzed the reduction of cyt c. The reaction of DNA with cyt c led to an electrochemically active complex, which resulted in an increase in the reduction current of cyt c. After adding DNA into the solution containing cyt c, the electrode process was still quasi-reversible with adsorption.