Electrochemical deposition is a versatile surface modification technology for the realization of advanced coatings for electrochemical sensor applications. This paper proposed a simple electrodeposition approach to synthesis graphene- chitosan composite onto glassy carbon electrode. The whole procedure was simple and it last only several minutes. Moreover, combining the advantages of graphene( large surface- to- volume ratio and high conductivity) and chitosan( good mechanical strength and adsorption), the composite film could be highly efficient to use in surface electrode [1-3]. Although the feasibility of chitosan electrodeposition was already demonstrated, here we have showed that chitosan acts as a protective layer enhancing the stability of graphene sensor. Graphene can be synthesized by chemically reduction of graphene oxide. On the other hand, the use of reducing agents also have several disadvantages. These materials have a potential health hazard and high expense. Thus graphene electrodeposition approach for construction of graphene based was environmental friendly. Also, compared with conventional methods producibility of film preparation has significantly improved [4]. Graphene oxide structure were investigated by Fourier trasform infra red spectroscopy (FT-IR) and scanning electron microscopy (SEM). The electrode was characterized using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Here we used cyclic voltammetry for graphene deposition and chorno potentiometry for chitosan deposition. The effect of influential parameters such as mass of graphene oxide, pH, cycle numbers, the sonication time and scan rate in firs step deposition and chitosan solution concentration, pH, time and current of deposition in second step were optimized to obtain the maximal sensitivity.

Keywords