Sensitive and Selective Redox, Chromogenic, and 鈥淭urn-On鈥?Fluorescent Probe for Pb(II) in Aqueous Environment

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• 作者：Arunabha Thakur ; Dipendu Mandal ; Sundargopal Ghosh
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：February 5, 2013
• 年：2013
• 卷：85
• 期：3
• 页码：1665-1674
• 全文大小：676K
• 年卷期：v.85,no.3(February 5, 2013)
• ISSN：1520-6882

文摘

The electrochemical, optical, and metal cation sensing properties of the triazole-tethered ferrocene鈥揳nthracene conjugates, C₄₈H₄₀FeO₂N₆ (3) and C₅₂H₄₀FeO₂N₆ (4), and the ferrocene鈥損yrene conjugates, C₂₉H₂₅FeON₃ (5) and C₃₁H₂₅FeON₃ (6), have been documented. All the compounds 3鈥?b>6 behave as very selective redox, chromogenic, and 鈥渢urn-on鈥?fluorescent probes for Pb²⁺ ion in an aqueous environment (CH₃CN/H₂O, 2/8). The significant changes in their absorption spectra are accompanied by a strong color change from yellow to greenish blue, which allows a prospective use for the 鈥渘aked eye鈥?detection of Pb²⁺ ion over other competitor cations such as Hg²⁺ and Cd²⁺. These chemosensors present immense brightness and fluorescence enhancement (chelation-enhanced fluorescence = 85 for 3 and 92 for 4) following Pb²⁺ coordination within the limit of detection at 2 ppb. Interestingly, their fluorescence, redox, and colorimetric responses are preserved in presence of water, which can be used for the selective colorimetric detection of Pb²⁺ ion in aqueous environment over Hg²⁺ and Cd²⁺ cations. All the compounds have been characterized by ¹H, ¹³C NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS) spectrometric analysis, and the solid-state structures of 5 and 6 have been unequivocally established by X-ray diffraction analysis.