基于铁基金属有机骨架电化学传感器检测食品中的Cd2+和Pb2+

Determination of Cd2+ and Pb2+ in food by electrochemical sensor based on organic skeleton of iron foundation

中文关键词:  电化学分析  Cd2+  Pb2+  铁基金属有机骨架  多壁碳纳米管

英文关键词:electrochemical analysis  Cd2+  Pb2+  iron-base metalorganic frameworks  multi-walled carbon nanotube

中文摘要:

      目的 制备铁负载于六羟基三亚苯基苯水合物(2,3,6,7,10,11-hexahydroxytriphenylene hydrate, Fe-HHTP), 将其修饰到玻碳电极(glassy carbon electrode, GCE)上, 构建新型电化学传感器用以快速检测食品中的Cd2+和Pb2+。方法 利用一步法制备Fe-HHTP, 随后将其与多壁碳纳米管(multi-walled carbon nanotube, MWCNT)协同作用后滴涂在玻碳电极表面, 构建Fe-HHTP-MWCNT/GCE传感器, 使用循环伏安法(cyclic voltammetry, CV)和电化学阻抗法(electrochemical impedance spectroscopy, EIS)对材料进行电化学检测表征, 并用差分脉冲阳极溶出伏安法(differential pulse anodic stripping voltammetry, DPASV)同时检测食品中的Cd2+和Pb2+。结果 Cd2+和Pb2+在pH 5.75的醋酸盐缓冲液、富集电位为-1.0 V、富集时间为180 s、修饰涂层为3层时, 溶出峰电流最大。在优化条件下, 发现Cd2+和Pb2+的溶出峰电流的变化趋势和浓度有关, 并形成了良好的线性关系。Cd2+和Pb2+的线性范围为5~500 ng/mL, 线性相关系数(r2)分别为0.9993和0.9997, 检出限分别为0.538和0.592 ng/mL。结论 该法可用于检测粮食、饮料、生活饮用水中Cd2+和Pb2+的含量。

英文摘要:

      Objective To prepare iron loaded 2,3,6,7,10,11-hexahydroxytriphenylene hydrate (Fe-HHTP) and modifie on glass carbon electrode (GCE) to construct a new electrochemical sensor for rapid detection of Cd2+ and Pb2+ in food. Methods Fe-HHTP was prepared by a one-step method, and then it was synergized with multi-walled carbon nanotube (MWCNTs) and then drop-coated on the surface of glassy carbon electrodes to construct Fe-HHTP-MWCNT/GCE sensors. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the materials by electrochemical detection, and differential pulse anodic stripping voltammetry (DPASV) was used to simultaneously detect Cd2+ and Pb2+ in food. Results The experimental results showed that Cd2+ and Pb2+ had obvious effects when the pH of acetate buffer was 5.75, the enrichment potential was ?1.0 V, the enrichment time was 180 s, and the modified coating was 3 layers. Under the optimized conditions, it was found that the variation trend of the dissolution peak current of Cd2+ and Pb2+ was related to the concentration, and a good linear relationship was formed. While the concentraltion range of 5?500 ng/mL, the linear correlation coefficients (r2) were 0.9993 and 0.9997, and the limits of detection were 0.538 and 0.592 ng/mL, respectively. Conclusion The method can be used for the determination of Cd2+ and Pb2+ in food, beverage and drinking water.