Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-G1-5 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
Anal Chem. 2010 Nov 15;82(22):9169-76. doi: 10.1021/ac101206j. Epub 2010 Oct 25.
Selective electrochemical detection of As(III) using a highly sensitive platform based on a Au(111)-like surface is described. The Au(111)-like surface was achieved for the first time by the partial reductive desorption of n-butanethiol (n-BT) from polycrystalline gold (poly-Au), on which a self-assembled monolayer (SAM) of n-BT was formed previously, which allows the selective blockage of the Au(100) and Au(110) surface domains by n-BT while the Au(111) domain remains bare. Square wave anodic stripping voltammetry (SWASV) using the Au(111)-like poly-Au electrode confirms the successful detection of As(III) without any interference from Cu(II). The fabricated electrode is stable and highly sensitive even in the presence of Cu(II), and it shows a linear response for As(III) up to 15 μM. The detection limit (S/N = 3) toward As(III) is 0.28 ppb, which is far below the guideline value given by World Health Organization (WHO). The electrode was applicable for the analysis of spiked arsenic in tap water containing a significant amount of various other ion elements. The results indicate that the Au(111)-like poly-Au electrode could be promising for the electrochemical detection of trace level of As(III) in real samples without any interference from Cu(II).
本文描述了一种基于类似金(111)表面的高灵敏度平台，用于选择性电化学检测砷(III)。首次通过从先前形成了正丁硫醇(n-BT)自组装单层(SAM)的多晶金(poly-Au)上部分还原脱附 n-BT，实现了类似金(111)表面。这允许 n-BT 选择性地阻断 Au(100)和 Au(110)表面域，而 Au(111)域保持裸露。使用类似金(111)的 poly-Au 电极进行的方波阳极溶出伏安法(SWASV)证实，即使存在 Cu(II)，也可以成功检测到砷(III)，而没有任何干扰。即使存在 Cu(II)，所制备的电极也是稳定且高度灵敏的，并且对 As(III)的线性响应高达 15 μM。对 As(III)的检测限(S/N = 3)为 0.28 ppb，远低于世界卫生组织(WHO)给出的指导值。该电极可用于分析含有大量其他离子元素的自来水中添加的砷。结果表明，类似金(111)的 poly-Au 电极在没有 Cu(II)干扰的情况下，有望用于电化学检测实际样品中痕量的 As(III)。
