Detection of Cd, Pb, and Cu in non-pretreated natural waters and urine with thiol functionalized mesoporous silica and Nafion composite electrodes.
Detection of Cd, Pb, and Cu in non-pretreated natural waters and urine with thiol functionalized mesoporous silica and Nafion composite electrodes.
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DOI：
10.1016/j.aca.2008.05.029
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发表时间：
2008-07
影响因子：
6.2
通讯作者：
W. Yantasee;Busarakum Charnhattakorn;G. Fryxell;Yuehe Lin;C. Timchalk;R. Addleman
中科院分区：
文献类型：
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作者：
W. Yantasee;Busarakum Charnhattakorn;G. Fryxell;Yuehe Lin;C. Timchalk;R. Addleman
电化学传感器由于其便携性、现场可部署性和良好的检测限，在沃茨中有毒金属离子的环境监测方面具有巨大的潜力。然而，采用无汞方法的电化学传感器通常遭受金属离子的结合竞争和天然沃茨中有机物质和表面活性剂的污染，使得样品预处理如湿灰化是必要的。在这项工作中，我们已经开发了无汞传感器的复合材料的硫醇自组装单分子膜上的介孔支持（SH-SAMMS™）和玻璃碳电极上的Nafion。凭借SH-SAMMS™作为出色的金属预浓缩器和Nafion作为吸附剂的综合优势，传感器可以在最短的预浓缩时间（几分钟）内检测河水，汉福德地下水和海水中0.5ppb的Pb和2.5ppb的Cd，并且无需任何样品预处理。该传感器还可以同时检测2.5ppb的Cd、Pb和Cu。该电极具有较长的使用时间和优异的单电极和电极间重现性（5% R.S.D.）。8次连续测量后）。与SAMMS™-碳糊电极不同，SAMMS™-Nafion电极在含有白蛋白的样品中不会被污染，并且成功地检测了人尿液中的Cd。研究了影响SAMMS™-Nafion电极金属检测的其他潜在混杂因素，包括pH效应、金属离子的传输阻力和检测干扰。SAMMS™-Nafion复合传感器能够可靠地检测低金属浓度范围，无需样品预处理和污染，有可能成为下一代有毒金属环境和生物监测的金属分析仪。
Electrochemical sensors have great potential for environmental monitoring of toxic metal ions in waters due to their portability, field-deployability and excellent detection limits. However, electrochemical sensors employing mercury-free approaches typically suffer from binding competition for metal ions and fouling by organic substances and surfactants in natural waters, making sample pretreatments such as wet ashing necessary. In this work, we have developed mercury-free sensors by coating a composite of thiol self-assembled monolayers on mesoporous supports (SH-SAMMS™) and Nafion on glassy-carbon electrodes. With the combined benefit of SH-SAMMS™ as an outstanding metal preconcentrator and Nafion as an antifouling binder, the sensors could detect 0.5ppb of Pb and 2.5ppb of Cd in river water, Hanford groundwater, and seawater with a minimal amount of preconcentration time (few minutes) and without any sample pretreatment. The sensor could also detect 2.5ppb of Cd, Pb, and Cu simultaneously. The electrodes have long service times and excellent single and inter-electrode reproducibility (5% R.S.D. after 8 consecutive measurements). Unlike SAMMS™-carbon paste electrodes, the SAMMS™-Nafion electrodes were not fouled in samples containing albumin and successfully detected Cd in human urine. Other potentially confounding factors affecting metal detection at SAMMS™-Nafion electrodes were studied, including pH effect, transport resistance of metal ions, and detection interference. With the ability to reliably detect low metal concentration ranges without sample pretreatment and fouling, SAMMS™-Nafion composite sensors have the potential to become the next-generation metal analyzers for environmental and bio-monitoring of toxic metals.