复合纳米材料修饰丝网印刷电极检测土壤中铅和镉  

Detection of lead and cadmium in soil using composite nanomaterials modified screen-printed electrode

作　　者：刘宁 赵国[3] 王旭明 刘刚[1,2] Liu Ning;Zhao Guo;Wang Xuming;Liu Gang(Key Laboratory of Modern Precision Agriculture System Integration Research,Ministry of Education,China Agricultural University,Beijing 100083,China;Key Laboratory of Agricultural Information Acquisition Technology,Ministry of Agriculture and Rural Affairs,China Agricultural University,Beijing 100083,China;College of Artificial Intelligence,Nanjing Agricultural University,Nanjing 210031,China)

机构地区：[1]中国农业大学现代精细农业系统集成研究教育部重点实验室,北京100083 [2]中国农业大学农业农村部农业信息获取技术重点实验室,北京100083 [3]南京农业大学人工智能学院,南京210031

出　　处：《农业工程学报》2021年第13期180-189,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(32071898,32001411);中央高校基本科研业务费专项资金资助项目(2021TC111)。

摘　　要：为了快速、准确、低成本检测土壤中痕量Pb(Ⅱ)和Cd(Ⅱ),该研究应用电化学还原和滴涂方法制备了一种铋膜/Nafion/还原氧化石墨烯/离子液体复合纳米材料修饰的丝网印刷电极(Bi/Nafion/rGO/IL/SPE)。通过扫描电子显微镜、循环伏安法和能量色散谱手段表征了修饰电极的电化学分析性能,结果显示修饰材料增大了电极的比表面积、增强了电极的电子传输能力并提高了电极对目标重金属的沉积量。利用标准溶液优化了试验参数,最优参数下的修饰电极检测性能为:在1~80μg/L范围内,Pb(Ⅱ)和Cd(Ⅱ)的峰值电流与其浓度的校正模型决定系数分别为0.993和0.985,Pb(Ⅱ)和Cd(Ⅱ)的理论检测限分别为0.124和0.232μg/L(S/N=3)。应用实际土壤样品验证了Bi/Nafion/rGO/IL/SPE的实用性,结果显示:Pb(Ⅱ)和Cd(Ⅱ)的平均加标回收率分别为98.71%和98.93%,表明该修饰电极可以用于土壤中痕量Pb(Ⅱ)和Cd(Ⅱ)的检测。Lead Pb(Ⅱ)and cadmium Cd(Ⅱ)are toxic heavy metals,particularly difficult to be biodegraded in soil.Furthermore,lead and cadmium at trace levels can cause serious damage to brains,kidneys,blood,nerves,and other organs.A large amount of Pb(Ⅱ)and Cd(Ⅱ)can also be deposited in the soil environment after anthropogenic improper activities,such as sewage irrigation,the abuse of chemical fertilizers and pesticides,as well as the excessive discharge of industrial wastes.Pb(Ⅱ)and Cd(Ⅱ)can be absorbed by crops,and then accumulated in animals,finally enriched thousands of times into the human body under the biomagnification of the food chain,thereby causing economic losses and a great threat to human health.Therefore,it is highly urgent to accurately detect the accumulation of Pb(Ⅱ)and Cd(Ⅱ)in soil.An electrochemical Square Wave Anodic Stripping Voltammetry(SWASV)is widely utilized to combine with chemically modified working electrodes for the detection of heavy metal ions.Screen-Printed Electrodes(SPEs)have also been commonly used in recent years,due to easy preparation,disposable capability,and low cost.Particularly,SPEs with a small size are quite qualified as the sensing device of miniature electrochemical detection equipment,suitable for many detection scenarios,such as flow cells and microfluidics.In this study,electrochemical reduction and coating were applied to fabricate a modified SPE(Bi/Nafion/rGO/IL/SPE)with the bismuth film/Nafion/reduced graphene oxide/ionic liquid composite nanomaterials,to accurately,fast,and reliably detect trace Pb(Ⅱ)and Cd(Ⅱ)in soil with a low-cost.Cyclic Voltammetry(CV)was also selected to characterize the electron transport capability of the modified electrodes.It was found that the composite nanomaterials greatly improved the electron transport capability of SPE and the stripping voltammetry responses for Pb(Ⅱ)and Cd(Ⅱ)on the SPE.Moreover,Scanning Electron Microscopy(SEM)was utilized to characterize the morphology of the modified electrodes.It was found that the

关 键 词：重金属 土壤 离子液体 氧化石墨烯 铋膜 NAFION 丝网印刷电极 

分 类 号：S24[农业科学—农业电气化与自动化] O657.1[农业科学—农业工程]