基于席夫碱水解的HSO_4^-比色荧光探针的研究

Selective colorimetric and fluorescent sensing of HSO_4^- in aqueous media based on the hydrolysis of Schiff Base

以3-氨基-9-乙基咔唑和4-(三氟甲基)苯甲醛为原料一步合成了一种结构简单的席夫碱比色荧光探针L。在CH_3CN-H_2O(4∶1,v/v)溶液中加入HSO_4^-后L的荧光显著增强,并且溶液颜色由淡黄色变为无色,从而可实现对HSO_4^-的比色与荧光识别检测,检测限为1.56×10^(-7)mol·L^(-1)。通过~1H NMR和高分辨质谱证明其识别机理是HSO_4^-加入体系后使探针L发生水解。利用L对自来水中的HSO_4^-进行了检测,还将L做成试纸条用于水样中HSO_4^-的快速识别检测。

A new colorimetric and fluorescent probe L based on 3-amino-9-ethylcarbazole and 4-trifluoromethylbenzaldehyde was prepared and its sensing behavior toward various anions was explored. L exhibited selective fluorescent response toward HSO4^- with fluorescence intensity enhancement in CH3 CN-H2 O（ 4 ∶ 1,v/v） solution.In addition,L shows a highly selective colorimetric response to HSO4^- ions by changing its color from pale yellow to colorless.The sensor displayed high sensitivity to hydrogen sulfate and the detection limit was calculated to be 1. 56 × 10^-7 mol · L^-1. The sensing mechanism has been suggested to proceed via a hydrolysis process of the Schiff base group.The hydrolysis product has been isolated and further identified by ^1 H NMR and MS. Moreover,the probe could be used as a practical,visible colorimetric test kit for HSO4^-.