基于碳球/金纳米复合材料的电化学传感器用于铅和镉的检测研究

An electrochemical sensor based on CNS/AuNPs/Nafion modified electrode for the determination of Cd^2+and Pb^2+

本文通过绿色制备方法合成碳球(CNS),并将金胶纳米粒子(AuNPs)自组装到碳球的表面,此CNS/AuNPs纳米复合材料体现了较强的导电性、较大的比表面积和优良的化学稳定性。构建了CNS/AuNPs/Nafion电化学传感器,并将其用于Pb^2+和Cd^2+的检测,大大提高了电化学检测的灵敏度。Pb^2+在浓度为3.0×10^-8~5.0×10^-6 mol·L^-1范围内,溶出峰电流与离子浓度呈现良好的线性关系,检测限为1.1×10^-8 mol·L^-1。Cd^2+在浓度为8.0×10^-8~8.0×10^-6 mol·L^-1范围内,峰电流与离子浓度呈现良好的线性关系,检测限为2.7×10^-8 mol·L^-1。该电化学传感器还应用于实际生活水样中Pb^2+和Cd^2+的含量测定,取得满意结果。本方法绿色环保,灵敏度高,重现性好,在实际生活样品中重金属离子的检测方面具有较好的应用前景。

In this study,carbon nanospheres(CNSs),were produced by a“green”and cost-effective synthesis under hydrothermal conditions.Coupled with AuNPs,the CNS/AuNPs nanospheres showed good stability and excellent sensitivity.The CNS/AuNPs/Nafion modified electrode was fabricated for the detection of Cd^2+and Pb^2+by anodic stripping voltammetry.The CNS/AuNPs/Nafion electrochemical sensor can improve the sensitivity of heavy metal detection because of their good conductivity and stability and the large surface area,which can accelerate the electron transfer.A linear relationship existed between the currents and concentrations of Pb^2+in the range of 3.0×10^-8 to 5.0×10^-6 mol·L^-1 with a detection limit of 1.1×10^-8 mol·L^-1,and the linear relationship for Cd^2+is between 8.0×10^-8 to 8.0×10^-6 mol·L^-1 with a detection limit of 2.7×10^-8 mol·L^-1.The CNS/AuNPs/Nafion electrochemical sensor was also applied to the determination of Pb^2+and Cd^2+in tap waterand river water.These studies indicated that the developed method was simple,sensitive,reproducible,and therefore has good practical application in electrochemical detection of metal ions.