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Abstract：
Present work reports, the development of a novel electrochemical sensor based on a diazonium-coupling reaction and covalent attachment of the -NH2 group of cysteamine (Cyst) on screen-printed carbon electrode (SPCE), for simultaneous determination of Pb(II) and Cd(II). Initially, the in-situ generated 4-carboxyphenyl (4-CP) diazonium salt was electro-grafted to generate 4-CP/SPCE, followed by covalent bonding of terminal carboxylic group of 4-CP with -NH2 group of Cyst to give Cyst/4-CP/SPCE. The modified electrode showed an enhanced selectivity and sensitivity toward the quantification of Pb(II) and Cd(II) using square wave anodic stripping voltammetry (SWASV) without mutual interference. Under optimal experimental conditions, the newly designed sensor showed a wide linear range of 0.01 µM to 0.7 µM. The limit of detection (LOD) obtained was 0.882 nM (0.09 ppb) and 0.65 nM (0.134 ppb) for Cd(II) and Pb(II), respectively. The modified SPCE exhibited good stability, selectivity, and reproducibility. Furthermore, the sensor was successfully applied for the determination of Pb(II) and Cd(II) ions in water samples which illustrated excellent recoveries in different spiked samples and the results were in line with the standard ICP-AES analysis.
摘要：
提交工作报告，基于重氮偶联反应和半胱胺（Cyst）的-NH2基团在丝网印刷碳电极（SPCE）上的共价连接的新型电化学传感器的开发，同时测定Pb(II)和Cd(II)。最初，将原位生成的4-羧基苯基(4-CP)重氮盐电接枝生成4-CP/SPCE,然后4-CP的末端羧基与Cyst的-NH2基团共价键合,得到Cyst/4-CP/SPCE。使用方波阳极溶出伏安法（SWASV），修饰电极对Pb（II）和Cd（II）的定量显示出增强的选择性和灵敏度，而不会相互干扰。在最佳实验条件下，新设计的传感器显示0.01µM至0.7µM的宽线性范围。对于Cd（II）和Pb（II），获得的检测限（LOD）为0.882nM（0.09ppb）和0.65nM（0.134ppb），分别。改性后的SPCE具有良好的稳定性,选择性,和再现性。此外，该传感器已成功用于水样中Pb（II）和Cd（II）离子的测定，在不同加标样品中具有良好的回收率，结果符合标准ICP-AES分析。
