Direct electrochemistry behavior of cytochrome c/l-cysteine modified electrode and its electrocatalytic oxidation to nitric oxide

Cytochrome c (Cyt c) was successfully immobilized on l-cysteine modified gold electrode by multicyclic voltammetry method. The electrochemical behavior of Cyt c on the l-cysteine modified electrode was explored. In 0.10 M, pH 7.0 phosphate buffer solution (PBS), Cyt c showed a quasi-reversible electrochemical redox behavior with Epc = 0.180 V, Epa = 0.208 V (versus Ag/AgCl). The Cyt c/l-cysteine modified electrode gave an excellent electrocatalytic activity towards the oxidation of nitric oxide, and the catalysis currents were proportional to the nitric oxide concentration in the range of 7.0 × 10− 7 to 1.0 × 10− 5 M, the linear regression equation is I (μA) = − 0.124–0.003CNO (μM), with a correlation coefficient 0.996, The detection limit was 3.0 × 10− 7 M (times the ratio of signal to noise, S/N = 3).