Direct electrochemical behavior of cytochrome c, and its determination on phytic acid modified electrode

摘要

Phytic acid (PA) with its unique structure was attached to a glassy carbon electrode (GCE) to form PA/ GCE modified electrode which was characterized by electrochemical impedance. The electrochemical behavior of cytochrome c (Cyt c) on the PA/GCE modified electrode was explored by cyclic voltammetry and differential pulse voltammetry. The Cyt c displayed a quasi-reversible redox process on PA modified electrode pH 7.0 phosphate buffer solution with a formal potential (E~0') of 57 mV (versus Ag/ AgCl). The peak currents were linearly related to the square root of the scan rate in the range of 20-120 mV·s~(-1). The electron transfer rate constant was determined to be 12.5 s~(-1). The PA/GCE modified electrode was applied to the determination of Cyt c, in the range of 5x10~(-6) to 3x 10~(-4) M, the currents increase linearly to the Cyt c concentration with a correlation coefficient 0.9981. The detection limit was 1 x 10~(-6) M (signaloise=3).