Amperometric method for the determination of myoglobin based on the electrochemical reduction on the glassy carbon electrode

An irreversible reduction peak of oxymyoglobin (MbO(2)) was observed on the bare glassy carbon electrode (GCE) in acetate buffer solution under atmosp heric conditions. It is the reduction of bonded oxygen in Mb, but not the h eme Fe(III)/Fe(II) redox couple that underwent electrochemical reaction on the electrode. The peak current achieved a maximum value in acetate buffer solution of pH 4.0. The peak potential was pH dependent, suggesting that th e proton was involved in the electrochemical reaction. Furthermore, the pea k current was linearly related to the concentration of myoglobin in the ran ge of 2.5 x 10(-8) similar to 1.0 x 10(-6) mol.L-1 with a detection limit o f 5 x 10(-9) mol.L-1.