Electrochemical insight into the cytochrome c adsorption on graphene and graphene oxide/self assembled monolayer surfaces and study of its electron transfer kinetics

The electrochemical property of cyt c on graphene (G) and graphene oxide (GO)/self assembled monolayer (SAM) surfaces were investigated by electrochemical techniques. Electrochemical response of cyt c on G/SAM showed an increase in peak separation and reduction in peak current. Cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM) results, suggest that the adsorption of cyt c on G/SAM is an unfavorable adsorption orientation for ET, so that the ET kinetics is higher on GO/SAM compared with G/SAM. The results show that cyt c is immobilized onto the GO/SAM surface by electrostatic interaction; whereas on G/SAM surface adsorbs by hydrophobic interaction.