聚酪氨酸原位镀铋复合膜修饰玻碳电极研究及Cd^2+分析应用  

Research on poly-tyrosine in situ bismuth plating composite film modified glassy carbon electrode and analysis of Cd^2+

作　　者：王燕如 翟文颖 颜芸 刘有芹 WANG Yan-ru;ZHAI Wen-ying;YAN Yun;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]华南农业大学材料与能源学院,生物基材料与能源教育部重点实验室,广东广州510642

出　　处：《化学研究与应用》2020年第9期1677-1684,共8页Chemical Research and Application

基　　金：广东省科技计划项目(2014A040401071,2015A030401080)资助。

摘　　要：首先采用循环伏安法制备了聚酪氨酸修饰玻碳电极。通过循环伏安法、交流阻抗谱及扫描电镜表征了其对[Fe(CN)6]^3-/4-的响应、电子传递阻抗及膜表面形态。聚酪氨酸膜呈芽状均匀分布于玻碳电极表面,能有效促进电子转移。然后采用原位镀铋制备了铋/聚酪氨酸复合膜修饰玻碳电极。以复合膜电极对Cd^2+方波阳极溶出伏安响应,探讨了聚酪氨酸修饰玻碳电极最佳制备条件及最佳测试介质。聚酪氨酸修饰玻碳电极制备液中酪氨酸最佳浓度为2.0 mmol·L^-1,聚合圈数为35。测试介质中Bi 3+最佳浓度3.0μmol·L^-1,pH为6.5,富集电位-1.3V。在最佳条件下,复合膜电极对Cd 2+响应的线性方程为:ip(μA)=-0.3264+44.33 c(μmol·L^-1)(r=0.9962),线性范围0.01~2.0μmol·L^-1,检测限1.2 nmol·L^-1(3 S/k)。复合膜电极成功用于大米样品中镉的测定,回收率90.0~95.7%,相对标准偏差小于3.8%。A poly-tyrosine modified glassy carbon electrode(p-Tyr/GC)was first prepared by cyclic voltammetry,whose response to[Fe(CN)6]^3-/4-,electron transfer impedance and membrane surface morphology were characterized by cyclic voltammetry,AC impedance spectroscopy and scanning electron microscopy,respectively.The p-Tyr membrane with bud shape evenly distributed on the surface of glassy carbon electrode and can effectively promote the electron transfer.Then,Bi/p-Tyr/GC electrode was prepared by in situ bismuth plating.Taking the square wave anodic stripping voltammetric response of a composite film electrode to Cd^2+ as reference,the optimum preparation conditions for p-Tyr/GC electrode and the optimal test medium were investigated.The optimal concentration of tyrosine and the number of cyclic voltammetry scan for p-Tyr/GC electrode preparation were 2.0 mmol·L^-1 and 35,respectively.The optimal concentration of Bi^3+ and pH in test medium were 3.0μmol·L^-1 and 6.5,respectively.The optimal accumulation potential was-1.3 V.Under the optimal conditions,the linear equation between the current response of p-Tyr/GC electrode to Cd^2+ and its concentration in the range of 0.01 to 2.0μmol·L^-1 was:i p(μA)=-0.3264+44.33 c(μmol·L^-1)(r=0.9962).The detection limit was 1.2 nmol·L^-1(3 S/k).The Bi/p-Tyr/GC electrode was successfully used for the determination of cadmium in rice samples with a recovery of 90.0-95.7%and a relative standard deviation less than 3.8%.

关 键 词：聚酪氨酸 铋膜 玻碳电极 重金属 方波阳极溶出伏安法 

分 类 号：O657.1[理学—分析化学]