Colorimetric Iodide Recognition and Sensing by Citrate-Stabilized Core/Shell Cu@Au Nanoparticles

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• 作者：Jia Zhang ; Xiaowen Xu ; Cheng Yang ; Fan Yang ; Xiurong Yang
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：May 15, 2011
• 年：2011
• 卷：83
• 期：10
• 页码：3911-3917
• 全文大小：1049K
• 年卷期：v.83,no.10(May 15, 2011)
• ISSN：1520-6882

文摘

In the light of the significance and urgency for the recognition and sensing of anions specifically, especially those of biological relevance, herein, we wish to demonstrate a novel colorimetric avenue for highly selective iodide recognition and sensing using simple citrate-stabilized core/shell Cu@Au nanoparticles. No other ions than iodide can induce an appreciable color change of the Cu@Au nanoparticles solution from purple to red by transforming the interconnected, irregularly shaped nanoparticles to the single, separated, and nearly spherical ones, as confirmed by the transmission electron microscopy (TEM). On the basis of the optical spectra and TEM studies, a mechanism of iodide-induced aggregating/fusion, fragmentation, and reorganization of atoms is proposed. With this strategy, 6 渭M (0.76 ppm) of iodide can be recognized within 20 min by naked-eye observation. This sensitive and selective colorimetric assay opens up a fresh insight of facile, rapid, and reliable detection of iodide and may find its future application in the analysis of the total iodine in edible salt as well as the clinical diagnosis of urinary iodide.