Highly sensitive multiresponsive chemosensor for selective detection of Hg2+ in natural water and different monitoring environments.
Highly sensitive multiresponsive chemosensor for selective detection of Hg2+ in natural water and different monitoring environments.
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DOI：
10.1021/ic8004344
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发表时间：
2008-07
影响因子：
4.6
通讯作者：
Dayu Wu;Wei Huang;Zhihua Lin;Chunying Duan;Cheng He;Shuo Wu;Dehui Wang
中科院分区：
文献类型：
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作者：
Dayu Wu;Wei Huang;Zhihua Lin;Chunying Duan;Cheng He;Shuo Wu;Dehui Wang
设计并制备了一种新型化学传感器RF1，该传感器通过碳腙结合单元的连接将二茂铁单元和罗丹明块结合在一起，用于高选择性检测天然水中的Hg（2+）。该化学传感器在十亿分之一（ppb）的汞（2+）检测范围内显示出极大的亮度和荧光增强。在ppb水平上，荧光强度几乎与Hg（2+）的量成正比。它能够区分饮用水中无机汞的安全水平和有毒水平。Hg（2+）的结合也引起RF1中罗丹明部分的显著吸收，Hg（2+）的显色检测限为50 ppb。因此，传统的紫外-可见光谱方法有可能为工业废水排放汞危害评估提供关键信息。加入Hg（2+）后，滴定液的颜色由无色变为粉红色，具有明显的特征，说明RF1可以用于水中Hg（2+）的“裸眼”检测。Hg（2+）络合也引起二茂铁/二茂铁偶对氧化还原电位的显著变化。电化学响应为汞（2+）在百万分之一（ppm）水平的定量分析提供了可能性。对包括海水和淡水在内的天然水样品的初步调查表明，RF1在复杂介质中提供了直接和即时的Hg（2+）检测，指出了其在环境监测和评估中的潜在用途。RF1对Hg（2+）具有特异性，该化学传感器对Hg（2+）的选择性高于其他12族金属、碱金属、碱土金属和大多数二价第一排过渡金属。RF1-Hg（2+）配合物被成功分离，Hg（2+）结合是可逆的。研究了含有一个二茂铁基团和两个罗丹明6G基团的同系物RF2的晶体结构和光谱性质。
A new chemosensor RF1 that combines a ferrocene unit and a rhodamine block via the linkage of a carbohydrazone binding unit was designed and prepared for the highly selective detection of Hg (2+) in natural water. This chemosensor displays great brightness and fluorescence enhancement following Hg (2+) coordination within the limit of detection for Hg (2+) at 1 parts per billion (ppb). The fluorescence intensities are nearly proportional to the amount of Hg (2+) at the ppb level. It is capable of distinguishing between the safe and the toxic levels of inorganic mercury in drinking water. Hg (2+)-binding also arouses the absorption of the rhodamine moiety in RF1 significantly with the chromogenic detection limit for Hg (2+) at 50 ppb. The conventional UV-vis spectroscopic method thus has the potential to provide the critical information about the mercury hazard assessment for industrial wastewater discharging. The obvious and characteristic color change of the titration solution from colorless to pink upon the addition of Hg (2+) demonstrates that RF1 can be used for "naked-eye" detection of Hg (2+) in water. The Hg (2+) complexation also causes a significant shift of the redox potential about the ferrocene/ferrocenium couple. The electrochemical responses provide the possibility to quantitative analysis of Hg (2+) at the parts per million (ppm) level. Preliminary investigations in natural water samples including seawater and freshwater indicate that RF1 offers a direct and immediate Hg (2+) detection in complex media, pointing out its potential utility in environment monitoring and assessment. The responses of RF1 are Hg (2+) specific, and the chemosensor exhibits high selectivity toward Hg (2+) over other Group 12 metals, alkali, alkaline earth metals, and most of the divalent first-row transition metals. The RF1-Hg (2+) complex is successfully isolated and the Hg (2+)-binding is reversible. The crystal structure and spectral properties of its congener RF2 that contains one ferrocene group and two rhodamine 6G moieties were also investigated for a comparison.