玻碳电极的石墨烯修饰研究及其电化学应用

Electrochemically reduced graphene modified electrode and its electrochemical application

为了提高重金属镉的测定速度,本研究采用石墨烯（R-GO）对玻碳电极进行修饰,并应用于食品中镉的测定。采用滴涂法将氧化石墨烯修饰到玻碳电极表面,考察了电解质及p H、修饰剂用量、富集时间和富集电位对镉离子检测的影响,并优化了检测条件,建立了测定大米制品中镉的差分脉冲伏安分析法（DPV）。结果表明镉离子的溶出峰电流与其浓度在4×10-8-3×10-5g/L（r=0.9962）范围内呈良好的线性关系,检测限为3.0×10-9g/L。使用石墨烯修饰电极对镉含量为4.0×10-6g/L溶液平行测定6次的RSD为8.53%。将本法应用于大米样品中镉的检测可以得到平均回收率为96.25%-111.25%。石墨烯修饰玻碳电极体现出良好的稳定性、重现性,在裸玻碳电极检测的基础上降低了检出限,故本法是一种可靠、快捷、灵敏的检测方法,为快速监测食品中的镉元素提供技术支撑。

A glassy carbon electrode was modified by single- step electrodeposition of graphene（ R- GO） for the rapid detection of cadmium and the electrochemical behavior on this electrode was investigated at the same time.The oxidation peak current of Cd2 ＋increased at the R- GO / GCE compared with bare GCE. A sensitive and fast analysis method（ differential pulse voltammetry,DPV） of Cd2 ＋in food systems was established.Under the optimum conditions,a linear relationship existed between electrical peak current and the concentration of Cd2 ＋in the range between 4 × 10- 8g / L and 3 × 10- 5g / L,with a detection limit of 3.0 × 10- 9g / L,the RSD for cadmium（ concentration= 4.0 × 10- 6g / L,n = 6） was 8.53%. This method has been applied to the detection of Cd2 ＋in rice with a successfully result,the average recoveries are between 96.25% - 111.25%. R- GO / GCE demonstrated an extraodinary satability and reproducibility,a better detection limit compared with GCE.The combination of R- GO /GCE and DPV turned out to be a solid,efficient and sensitive method and technical support for the rapid detection of cadmium in food.