摘要
为制备用氮掺杂石墨烯(NG)和发夹脱氧核糖核酸(HDNA)修饰的玻碳电极(GCE),先取1.0g·L^-1氮掺杂石墨烯溶液5.0μL,滴在GCE表面,晾干后得NG/GCE。然后取5.0μmol·L^-1 HDNA溶液10.0μL,滴于NG/GCE表面,在4℃冰箱中孵育2h。应用透射电镜及扫描电镜对NG进行表征,并用循环伏安法(CV)和差分脉冲伏安法(DPV)对百草枯在上述修饰电极(作为工作电极)上的电化学行为进行考察。结果表明:在0.1mol·L^-1磷酸盐缓冲溶液(pH8.0)中,百草枯在电位-0.523V处有一明显的还原峰,且在所研制的修饰电极上的电流响应值(21.08μA)比在GCE上的电流响应值(2.102μA)高。百草枯的浓度在6.0×10^-8~4.0×10^-5 mol·L^-1内与其对应的还原峰电流呈线性关系,检出限(3s/k)为1.6×10^-8 mol·L^-1。应用所提出的方法测定了土壤、水及小鼠血浆中百草枯的残留量,以土壤样品为基体进行加标回收试验,所得回收率为81.7%~107%。
To prepare the modified electrode of HDNA/NG/GCE,NG/GCE was prepared preliminarily by applying 5.0μL of 1.0 g·L^-1 NG solution onto the surface of GCE,which was then dried in air.And afterwards,10.0μL of 5.0μmol·L^-1 HDNA solution was applied onto the surface of NG/GCE,which was incubated in a refrigerator at 4 ℃ for 2 h.TEM and SEM were applied to characterize specificity of NG and electrochemical methods of CV and DPV were applied to study the electrochemical behavior of paraquat(PQ)at the modified electrode as working electrode.It was found that①in a 0.1 mol·L^-1 PBS of pH 8.0,a significant reduction peak given by PQ was observed at the potential of-0.523 V;② value of reduction peak current of PQ obtained at the modified electrode(21.08μA)was greater than that obtained at the GCE(2.102μA);and ③linear relationship was found between values of reduction peak current and the corresponding concentration of PQ in the range from6.0×10^-8 mol·L^-1 to 4.0×10^-5 mol·L^-1,with detection limit(3 s/k)of 1.6×10^-8 mol·L^-1.The proposed method was applied to the determination of residual amount of PQ in substantial samples of soil,water and mouselet plasma.Tests for recovery were made by standard addition method using soil samples as matrixes,values of recovery found were in the range from 81.7%to 107%.
作者
贾丽丛
康凯
马新颜
牛凌梅
马莉
康维钧
JIA Licong;KANG Kai;MA Xinyan;NIU Lingmei;MA Li;KANG Weijun(Hebei Province Key Laboratory of Evironment and Human Health,School of Public Health,Hebei Medical University,Shijiazhuang 050017,China;School of Pharmaceutical Sciences,Hebei Medical University,Shijiazhuang 050017,China)
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2019年第11期1281-1286,共6页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
河北省杰出青年基金(H2016206557)
作者简介
贾丽丛,助理实验师,主要从事农药残留检测工作;通信联系人:马莉,mali@hebmu.edu.cn。
