基于石墨烯的镉离子电化学传感器

An Electrochemical Sensor for the Determination of Cd2+Based on Graphene

采用电化学法还原氧化石墨烯,构建石墨烯修饰玻碳电极（GCE）,选用方波伏安法（SWV）测定微量镉.实验研究了石墨烯修饰电极对镉的溶出伏安行为,优化了石墨烯用量、富集电位、富集时间、pH值、支持电解质.结果表明石墨烯修饰电极明显增强了镉溶出信号,响应电流值与Cd^2＋的浓度呈良好的线性关系,线性范围为0.001-1μg/mL,线性方程y=27.859 2x＋0.344 5（R=0.998）,检出限为0.001μg/mL,所制备的修饰电极重现性和重复性较好,6次测定的相对标准偏差（RSD）分别为2.56%和2.51%.所提出的检测方法简单、灵敏、快速,无需复杂的样品前处理,修饰电极可重复使用,能应用于实际水样中镉的快速测定.

An electrochemical sensor of Cd^2＋was constructed by electrochemical reduction of graphene oxide on the glassy carbon electrode（GCE）.The determination of Cd^2＋was proceeded by square wave voltammetry（SWV）.Stripping voltammetric behavior of Cd at graphene modified electrode was studied.The amount of graphene,deposition potential,deposition time,pH and the supporting electrolyte were optimized.In comparison with the bare glassy carbon electrode,the response signal of the graphene modified GCE was obviously increased.Under the optimal conditions,the linear calibration curve ranges from 0.001 to 1μg/mL.The linear equation was y=27.859 2x＋0.344 5（R=0.998）.The detection limit was 0.001μg/mL.The reproducibility and repeatability were also investigated with RSD of 2.56%（n=6）and 2.51%（n=6）,respectively.Owing to its simple fabrication,high sensitivity,fast response,good stability and repeatability,the developed sensor can serve as promising electrochemical platform for the detection of Cd^2＋in real samples.