碳纳米颗粒修饰丝网印刷电极测定百合镉含量  

Detection of cadmium content of lily by carbon nanoparticles modified screen-printed electrode

作　　者：郑琦琦[1] 俞永华[1] 吴坚[1] 

机构地区：[1]浙江大学生物系统工程与食品科学学院,杭州310058

出　　处：《农业工程学报》2015年第20期274-280,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省现代农业装备与技术协同创新中心项目"农产品安全信息的智能感知技术与装备"(NZXT01201402)

摘　　要：该文利用烛灰,设计开发一种基于碳纳米颗粒修饰的丝网印刷电极,并对该电极的性能进行了评估。扫描电子显微镜显示修饰后的工作电极表面碳纳米颗粒分布均匀,直径约几十纳米。电极表征时,修饰电极氧化峰高13.76 m A,还原峰高11.85 m A,峰电位差为267 m V。在使用方波阳极溶出法检测含75μg/L Cd2＋缓冲液时,修饰电极峰高为3.123μA。使用修饰电极检测不同Cd2＋浓度缓冲液时,将峰高与Cd2＋浓度进行数量关系拟合,获得拟合方程,R2=0.998。该修饰电极Cd2＋浓度检测限可达到0.91μg/L。将其用于百合样本检测,加标回收率为99.2%~100.8%。该文修饰碳纳米颗粒丝网印刷电极可为其他检测对象或其他检测环境下的检测提供参考。People are more and more interested in health foods with the improvement of living standard. Edible lily tastes sweet with a little bitter and can be used to treat cough, phthisis, beriberi, and so on. There are almost 10 species of edible lily in China. The production of lily is in rapid expansion. However, the sample of lily is usually found to have cadmium（Cd） above the national standard. Cd is one of the toxic heavy metals. It will cause damage of lung and kidney. There are a lot of methods to detect the cd in foods, such as graphite furnace atomic absorption spectrometry, atomic fluorescence spectrometry, and spectrophotometry. Although these methods have high precision, they need large-scale equipment, high cost, and professional staff, and even some use toxic reagents. Scientists developed several rapid determination methods, one of which was electrochemical detection. In this paper, we designed a novel electrode, which combined screen printing technique with carbon nanodots to detect cd in lily. Carbon nanodots were prepared with candle soot which was low-cost and easily obtained. The carbon nanodots of 1.5 μL dissolving in dimethyl formamide were added twice onto the working electrode of screen-printed electrode which was fabricated in our laboratory. Using scanning electron microscope to compare the surface texture of modified screen-printed electrode with original one, we found that the former had more uniform particles. We also compared the electrochemical performance by cyclic voltammetry. The result showed that the modified screen-printed electrode had larger peak current and smaller peak separation which meant superior electrochemical performance. Furthermore, we tested an HAc-Na Ac buffer solution with 75 μg/L Cd2＋ using 2 different electrodes noted above by square-wave anodic stripping voltammetry. The peak potential of original screen-printed electrode was-0.65 V, while modified one was-0.64 V. The anodic stripping voltammogarm showed that the carbon nanodots modified electrode had large

关 键 词：农产品 污染 检测 食用百合 镉 碳纳米颗粒 阳极溶出法 

分 类 号：S567.23[农业科学—中草药栽培]