Structural modification of rhodamine-based sensors toward highly selective mercury detection in mixed organic/aqueous media.
Structural modification of rhodamine-based sensors toward highly selective mercury detection in mixed organic/aqueous media.
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DOI：
10.1039/b914490k
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发表时间：
2009-11
影响因子：
4
通讯作者：
Wei Huang;Xiang Zhu;Dayu Wua;Cheng He;Xiaoyue Hu;Chunying Duan
中科院分区：
文献类型：
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作者：
Wei Huang;Xiang Zhu;Dayu Wua;Cheng He;Xiaoyue Hu;Chunying Duan
利用汞(2+)的亲硫性，设计并制备了三种新型传感器RN1、RN2和RST1，它们分别与一个或两个罗丹明生色团或硫代吡咯内酰胺罗丹明发色团结合，用于选择性检测水介质中的汞(2+)。这些传感器在汞(2+)配位后都表现出良好的亮度和荧光增强，对汞(2+)的检测限在ppb水平。因此，它们有可能区分饮用水中无机汞的安全和有毒水平。RN1对碱金属、碱土金属、二价第一过渡金属离子和重金属具有显色和荧光选择性，但铜(2+)的存在对汞(2+)的吸收检测有较小但显著的影响。与RN1相比，引入足够多的硫原子可以提高RST1与汞(2+)的结合能力，但降低了其对汞的专一性。铅(2+)、银(+)、铜(2+)等重金属离子和过渡金属离子的存在增强了RST1的无声吸收光谱。光谱证据和X射线结构研究表明，汞(2+)离子与传感器RN1或RST1之间可能存在1：2的络合行为。与RN1和RST1相比，含有两个罗丹明缩氨基臂的传感器RN2表现出更好的选择性。在相同条件下，Cu(2+)的加入对汞(2+)的吸收检测只有很小的干扰，证明了健壮的双络合模式对汞(2+)的选择性是有效的。
In virtue of the sulfurphilic nature of Hg(2+), three new sensors RN1, RN2 and RST1 that combine a thiophene group and one or two rhodamine choromophores, or a thiospirolactam rhodamine chromophore, were designed and prepared for the selective detection of Hg(2+) in aqueous media, respectively. These sensors all displayed good brightness and fluorescence enhancement following Hg(2+) coordination with limits of detection for Hg(2+) at the ppb level. Thus, they have the potential for distinguishing between safe and toxic levels of inorganic mercury in drinking water. RN1 exhibited chromogenic and fluorogenic selectivity over alkali, alkaline earth metals, divalent first-row transition metal ions as well as heavy metals, but the presence of Cu(2+) had a small but significant influence on the absorption detection of Hg(2+). Compared to RN1, the introduction of sufficient sulfur atoms could increase the binding capability of RST1 towards Hg(2+) relative to the sensor RN1, but decrease its Hg specific ability. The existence of some heavy and transition metal ions, such as Pb(2+), Ag(+), Cu(2+) enhance the silent absorption spectra of RST1. Spectral evidence and X-ray structural investigations of the mercury complex revealed a possible 1:2 complexation behaviour between the Hg(2+) ion and the sensor RN1 or RST1. Sensor RN2 which contains two rhodamine carboxhydrazone arms exhibited better selectivity, compared to those of RN1 and RST1. The addition of Cu(2+) only caused a small interference for the absorption detection of Hg(2+) under the same conditions, demonstrating the efficiency of the robust bis-chelating mode with regard to the selectivity for Hg(2+).