Electrochemical Detection of Arsenic(III) Completely Free from Noble Metal: Fe3O4 Microspheres-Room Temperature Ionic Liquid Composite Showing Better Performance than Gold
Electrochemical Detection of Arsenic(III) Completely Free from Noble Metal: Fe3O4 Microspheres-Room Temperature Ionic Liquid Composite Showing Better Performance than Gold
复制标题
电化学检测完全不含贵金属的砷(III)：Fe3O4微球-室温离子液体复合材料表现出比金更好的性能
DOI：
10.1021/ac303143x
复制
发表时间：
2013-03-05
影响因子：
7.4
通讯作者：
Huang, Xing-Jiu
中科院分区：
文献类型：
--
作者：
Gao, Chao;Yu, Xin-Yao;Huang, Xing-Jiu
近几十年来，电化学检测砷(III)有了革命性的发展，具有更高的灵敏度和更低的检测下限。但在强酸性条件下，As(III)的电化学检测仍然严重依赖贵金属(以Au为主)，增加了成本，阻碍了As(III)的广泛应用。在这里，我们报道了一种完全不含贵金属的一次性平台，用于在近中性条件下方波阳极溶出伏安法电化学检测饮用水中的As(III)。结合Fe3O4微球对As(III)的高吸附能力和室温离子液体(RTIL)的优点，Fe3O4-RTIL复合修饰丝网印刷碳电极(SPCE)表现出比常用贵金属更好的电化学性能。几种不同粘度和表面张力的离子液体对As(III)的伏安行为有不同的影响。在优化的条件下，Fe3O4-RTIL复合材料可在世界卫生组织(WHO)规定的理想范围(10 Ppb)内直接检测饮用水中的As(III)，检出限(3sigma法)为8×10(-4)ppb。获得的灵敏度为4.91µA ppb(-1)，是目前已知的最高灵敏度。此外，还提出了一种可能的基于吸附的As(III)预富集机理，并得到了设计实验的支持。最后，将该平台成功地应用于内蒙古中国的实际样本分析。
In recent decades, electrochemical detection of arsenic(III) has been undergoing revolutionary developments with higher sensitivity and lower detection limit. Despite great success, electrochemical detection of As(III) still depends heavily on noble metals (predominantly Au) in a strong acid condition, thus increasing the cost and hampering the widespread application. Here, we report a disposable platform completely free from noble metals for electrochemical detection of As(III) in drinking water under nearly neutral condition by square wave anodic stripping voltammetry. By combining the high adsorptivity of Fe3O4 microspheres toward As(III) and the advantages of room temperature ionic liquid (RTIL), the Fe3O4-RTIL composite modified screen-printed carbon electrode (SPCE) showed even better electrochemical performance than commonly used noble metals. Several ionic liquids with different viscosities and surface tensions were found to have a different effect on the voltammetric behavior toward As(III). Under the optimized conditions, the Fe3O4-RTIL composites offered direct detection of As(III) within the desirable range (10 ppb) in drinking water as specified by the World Health Organization (WHO), with a detection limit (3 sigma method) of 8 x 10(-4) ppb. The obtained sensitivity was 4.91 mu A ppb(-1), which is the highest as far as we know. In addition, a possible mechanism for As(III) preconcentration based on adsorption has been proposed and supported by designed experiments. Finally, this platform was successfully applied to analyzing a real sample collected from Inner Mongolia, China.