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Abstract：
In this study, a new carbon paste electrode modified with a laboratory-synthesized ligand, N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) and multi-walled carbon nanotubes (MWCNTs) (HDPBA‒MWCNTs/CPE) has been developed. The modified electrode was applied for preconcentration and voltammetric determination of zinc ions (Zn(II)) by square wave anodic stripping voltammetry (SWASV). The preconcentration of Zn(II) on the electrode surface was performed in 0.1 M Brinton Robinson (B-R) buffer solution (pH 6) at an applied potential of -1.30 V versus Ag/AgCl for 120 s, followed by stripping in the positive potential scan of the SWASV after a quit time of 10 s. Under optimized experimental conditions, the proposed electrode exhibited a wider linear dynamic response for Zn(II) in a concentration range of 0.02-10.00 μM with a detection limit of 2.48 nM. This is due to the excellent metal-chelation property of the ligand, and the good conductivity and large surface area of MWCNTs which significantly improved the sensing performance of the nanocomposite modified electrode. The selectivity of the electrode was studied by evaluating the interference effects of various foreign ions on the peak current of Zn(II). The method exhibited high reproducibility with a relative standard deviation (RSD) of 3.1%. The present method was applied for the determination of zinc ions in water samples. The recovery values in the tested samples were found to be 98.50-106.0%, indicating a good accuracy of the proposed electrode. Furthermore, the electrochemical behavior of HDPBA in acetonitrile and aqueous solutions has been studied.
摘要：
在这项研究中,用实验室合成的配体修饰的新型碳糊电极，已经开发了N1-羟基-N1，N2-二苯基苄脒（HDPBA）和多壁碳纳米管（MWCNTs）（HDPBA-MWCNTs/CPE）。该修饰电极用于方波阳极溶出伏安法（SWASV）预富集和伏安法测定锌离子（Zn（II））。在0.1MBrintonRobinson（B-R）缓冲溶液（pH6）中，在相对于Ag/AgCl的-1.30V的施加电势下，对电极表面进行Zn（II）的预浓缩120s，在10s的退出时间后，在SWASV的正电位扫描中进行剥离。在优化的实验条件下，所提出的电极在0.02-10.00μM的浓度范围内对Zn（II）表现出更宽的线性动态响应，检出限为2.48nM。这是由于配体具有优异的金属螯合性能，MWCNTs良好的导电性和较大的比表面积,显著提高了纳米复合修饰电极的传感性能。通过评估各种外来离子对Zn（II）峰电流的干扰作用，研究了电极的选择性。该方法具有高重现性，相对标准偏差（RSD）为3.1％。该方法用于水样中锌离子的测定。被测样品的回收率为98.50-106.0%，表明所提出的电极具有良好的准确性。此外，研究了HDPBA在乙腈和水溶液中的电化学行为。
