Differential Pulse Stripping Voltammetry Determination of Cadmium in Water Using Graphene Sheets-Au Composite Nano-particles Modified Screen-printed Carbon Electrodes

KeyWord:graphene sheets  gold nano-particles  screen-printed carbon electrode  differential pulse stripping voltammetry  cadmium

Abstract:

      An electrochemical sensor based on graphene sheets£¨GS£© and gold nano-particles£¨Au£© composite nano-particles modified screen-printed carbon electrodes£¨SPCEs£© was fabricated£¨SPCEs©¦GS/Au£©,and an electrochemical method was developed for the determination of trace cadmium£¨Cd£© in water by differential pulse stripping voltammetric£¨DPSV£©method.Au preparation and the construction processes of SPCEs©¦GS/Au electrode were characterized by scanning electron micrography£¨SEM£©,and the electrochemical properties of Cd2+ were investigated.Under the optimum conditions,a good linear relationship was obtained between peak current and Cd2+ concentration in the range of 2.5¡Á10-7-2.5¡Á10-5 g/L£¨r2=0.998 0£© with a detection limit£¨3¦Ò£© of 1.8¡Á10-7 g/L.The method was applied in the determination of Cd2+ concentration in real water samples with recoveries of 96%-107%.The analytical results were consistent with those of the graphite furnace atomic absorption spectrometric£¨GF-AAS£© method.The SPCEs©¦GS/Au electrode showed a high response current and an enrichment ability due to the modification of composite nano-particles.Therefore,the electrode was suitable for the determination of Cd2+ in water with advantages of disposable design,little sample consumption and simple operation.