基于聚酪氨酸/铋修饰玻碳电极的Pb^(2+)传感器研究  

Investigation on a Pb^(2+) Sensor Based on Polytyrosine/Bi/GC Electrode

作　　者：林婉芳 翟文颖 刘有芹 LIN Wan-fang;ZHAI Wen-ying;LIU You-qin(Key Laboratory for Biobased Materials and Energy of Ministry of Education,College of Materials and Energy,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]生物基材料与能源教育部重点实验室,华南农业大学材料与能源学院,广东广州510642

出　　处：《分析测试学报》2021年第3期383-388,共6页Journal of Instrumental Analysis

基　　金：广东省科技计划项目(2015A030401080,2014A040401071);海关总署科研项目(2019HK116)。

摘　　要：采用循环伏安法及原位镀铋制备了聚酪氨酸/Bi复合膜修饰玻碳电极(p-Tyr/Bi/GC),并用交流阻抗谱及扫描电镜表征了复合膜电极的电子传递阻抗及表面形态。发现聚酪氨酸膜能促进电极表面电子交换,有利于高灵敏Pb^(2+)传感器的研制。以复合膜电极对Pb2+的方波阳极溶出伏安响应电流探讨了聚酪氨酸修饰玻碳电极的最佳制备及测试条件。结果表明电极制备液中酪氨酸的最佳浓度为1.5 mmol·L^(-1),聚合圈数为15;测试液中Bi3+的最佳浓度为1.0μmol·L-1,pH值为6.0,富集电位为-1.20 V。在最佳条件下,复合膜电极对Pb2+的响应线性方程为:Ip(μA)=0.5032+54.68c(μmol·L-1)(r=0.9947),线性范围为0.01~0.16μmol·L^(-1),检出限(3S/k)为0.8 nmol·L^(-1)。复合膜电极具有灵敏度高、稳定性好、抗干扰能力强的特点,用于茶叶样品中铅的测定,回收率为90.6%~96.3%,相对标准偏差不大于3.9%。A polytyrosine/bismuth modified glassy carbon electrode(p-Tyr/Bi/GC)was firstly prepared by cyclic voltammetry with in situ bismuth plating.The electron transfer impedance and membrane surface morphology on the electrode were characterized by EIS and SEM.The p-Tyr membrane with flower shape evenly distributed on the surface of glassy carbon electrode,which could effectively promote the electron transfer.Taking the square wave anodic stripping voltammetric response of a composite film electrode to Pb^(2+) as a reference,the optimum preparation conditions for the p-Tyr/Bi/GC electrode and the optimal test medium were investigated.The optimal concentration of tyrosine and number of cyclic voltammetry scan for p-Tyr/GC electrode preparation were 1.5 mmol·L^(-1) and 15,respectively.The optimal Bi3+concentration,pH value and accumulation potential in test medium were 1.0μmol·L^(-1),6.0,and-1.20 V,respectively.Under the optimal conditions,the linear equation between the current response of the electrode to Pb^(2+) and its concentration in the range of 0.01-0.16μmol·L^(-1) was Ip(μA)=0.5032+54.68c(μmol·L^(-1))(r=0.9947),with a detection limit(3S/k)of 0.8 nmol·L^(-1).With high sensitivity,good stability and strong anti-interference ability,the p-Tyr/Bi/GC electrode was successfully used for the determination of lead in tea samples with recoveries of 90.6%-96.3%and relative standard deviations not more than 3.9%.

关 键 词：聚酪氨酸 铋 玻碳 铅 方波阳极溶出伏安法 

分 类 号：O657.1[理学—分析化学] O614.433[理学—化学]