基于吲哚克酮酸染料的Ag^+比色/荧光识别探针

Indolium Croconine-Based Colorimetric and Fluorescent Chemosensor for Detecting Ag^+

以纳米氧化铜为催化剂合成了克酮酸,将它与2,3,3-三甲基-3H-吲哚经缩合反应得到吲哚克酮酸染料(ICR),利用紫外-可见(UV-Vis)吸收光谱考察了其对Na+、K+、Mg2+、Ca2+、Ni2+、Mn2+、Zn2+、Ag+和Ba2+的阳离子识别作用。结果表明,当加入Ag+时,ICR的乙醇-水溶液〔V(C2H5OH)∶V(H2O)=4∶1〕吸光度降低,且溶液颜色由橄榄绿色变为橘黄色,而加入其他阳离子则无变化。研究了Ag+对ICR的乙醇-水溶液〔V(C2H5OH)∶V(H2O)=4∶1〕荧光发射光谱的影响,同样发现只有Ag+能使其荧光猝灭,显示了ICR对Ag+具有较高的选择性及灵敏性。此外,通过循环伏安法和1HNMR探究了该化合物对Ag+的识别作用机理。

Indole croconium dye was obtained by condensation reaction between 2, 3, 3- trimethylindolenine and croeonic acid which was previously prepared using copper oxide as catalyst. The binding properties of the receptors with cations such as Na ^＋ , K^＋ , Mg^2＋ , Ca^2＋ , Ni^2＋ , Mn^2＋ , Zn^2＋ , Ag^＋ and Ba^2＋ were investigated by UV-Vis spectroscopy. The results show that the absorbanee obviously decreased upon the addition of Ag^＋ into ICR ethanol/water （ volume ratio 4 ： 1 ）. Moreover, there was a clear color change from olive green to orange. Meanwhile,the fluorescence spectra of ICR ethanol/water（ volume ratio 4：1 ） were investigated by adding Ag ＋ ion of increasing concentration. It was found that the fluorescence strength of ICR ethanol/water（ volume ratio 4：1 ） was quenched. The results indicate that ICR exhibited highly selective and sensitive recognition towards Ag^＋. The cyclic voltammetry and ^1HNMR were also used for the recognition study of ICR to transition metal ions.