A graphene-based electrochemical sensor for sensitive determination of cyanazine

An electrochemical sensor based on the electrocatalytic activity of graphene for sensitive detection of cyanazine (CZ) is presented. Graphene is ideally suited for electrochemical applications due to its large electrical conductivity, large surface area and unique heterogeneous electron transfer rate. Electrochemical measurements were performed at glassy carbon electrode (GCE) which was modified with graphene via drop-casting method. Cyclic voltammogram of ferri/ferrocyanide redox couple at graphene modified electrode showed an increased current intensity compared with glassy carbon and graphite modified electrode. The decrease of charge transfer resistance was also analyzed by electrochemical impedance spectroscopy. The morphology of the modified graphene electrode was characterized using scanning electron and atomic force microscopic techniques. Under the optimized experimental conditions, the proposed electrochemical sensor exhibited a rapid response to cyanazine with a linear calibration plot ranging from 0.55 to 1500 nM and a detection limit of 0.25 nM. The applicability of graphene/GCE for the determination of CZ in real samples such as tape water, river water and ground water, were checked by differential pulse voltammetry method.