Key Laboratory of Coastal Zone Environmental Processes, CAS, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
Analyst. 2011 Nov 7;136(21):4526-32. doi: 10.1039/c1an15454k. Epub 2011 Sep 16.
A simple and efficient electrochemical assay based on self-assembled monolayers (SAMs) was developed for the highly sensitive determination of arsenic(III) in water samples. The synergy of glutathione (GSH), dithiothreitol (DTT) and N-acetyl-L-cysteine (NAC) mixed SAMs enhanced the detection specificity and sensitivity of As(III) in water samples, resulting from the immobilization of a large number of As(III) moieties on the gold electrode surface via As-O and As-S linkages. After accumulating As(III), anodic stripping voltammetry (ASV) was performed, and linear sweep voltammetry (LSV) was employed for signal recording. Several main voltammetric parameters were optimized as follows: supporting electrolyte, 1 mol L(-1) HCl; deposition potential, -0.35 V; deposition time, 150 s. A good linear relationship (R = 0.9980) was attained between the concentration of the As(III) standard and peak current, in the range of 3-100 μg L(-1). The limit of detection (LOD) of this sensing system was determined to be 0.5 μg L(-1) at a signal-to-noise ratio of 3. A variety of common coexistent ions in water samples were examined, showing no obvious interferences on the As(III) determination. The amenability of this method to the analyses of water samples was also investigated. High recovery of 90.5% with the precision of 5.1% at spiked 10 μg L(-1), and low LOD of 0.3 μg L(-1) were obtained in seawater. The synergy effect of GSH, DTT and NAC provided the possibility for the rapid and sensitive LSV determination of As(III) in complicated water samples.
基于自组装单层（SAMs）的简单高效电化学测定法被开发出来，用于高灵敏度测定水样中的砷（III）。谷胱甘肽（GSH）、二硫苏糖醇（DTT）和 N-乙酰-L-半胱氨酸（NAC）混合 SAM 的协同作用增强了水样中 As(III)的检测特异性和灵敏度，这是由于大量的 As(III)通过 As-O 和 As-S 键固定在金电极表面上。在积累 As(III)之后，进行阳极溶出伏安法（ASV），并采用线性扫描伏安法（LSV）进行信号记录。优化了几个主要的伏安参数如下：支持电解质，1 mol L(-1) HCl；沉积电位，-0.35 V；沉积时间，150 s。在 3-100 μg L(-1)范围内，As(III)标准浓度与峰电流之间呈现良好的线性关系（R = 0.9980）。该传感系统的检测限（LOD）在信噪比为 3 时确定为 0.5 μg L(-1)。还检查了水样中常见的共存离子，发现它们对 As(III)的测定没有明显的干扰。该方法也适用于水样的分析。在海水中，10 μg L(-1)的加标回收率为 90.5%，精密度为 5.1%，LOD 低至 0.3 μg L(-1)。GSH、DTT 和 NAC 的协同作用为在复杂水样中快速灵敏地进行 LSV 测定提供了可能性。
