The efficiency of graphene-cysteine nanocomposites to stabilize the enzyme glucose oxidase in the carbon electrode

In recent years, many efforts have been done to provide biological platforms for enzyme immobilization, biotechnology applications and biosensor developments. One of these platforms is cysteine amino acid. Much cysteine immobilization on the electrode surface, causing larger amount of protein loaded on the electrode surface which improves the biosensor’s operation. In the present study cysteine was fixed on bare glassy carbon electrode and glassy carbon electrode modified graphene or graphene oxide by electrochemical method. Cyclic voltammetry showed the best cysteine immobilization was on the glassy carbon electrode modified graphene. In addition, the use of cysteine-graphene nanocomposit on the glassy carbon electrode surface not only loading a larger amount of glucose oxidase enzyme on the surface of the modified electrode, but also providing the graphene as a good platform for facilitating electron transfer from the electrode to the redox enzyme