通过简单的还原反应构建了基于萘并2-氢-吲哚衍生物的具有微弱荧光的反应型铜离子荧光探针1,通过 ¹HNMR和MALDI-TOF MS对其结构进行了表征。研究结果表明,铜离子能够氧化探针1中N-乙基-2-氢-吲哚单元变为N-乙基-吲哚季铵盐单元,延长了探针1分子的共轭体系,产生卓越的光学性能变化;探针1对铜离子具有良好的选择性,且不受其他阳离子分析物的干扰,在弱碱性条件下探针1识别铜离子是非常迅速的过程,溶液颜色产生明显的变化,可以应用于"裸眼"识别复杂环境中铜离子;探针1溶液中逐渐滴加铜离子后荧光信号逐渐增强,且荧光强度变化与加入铜离子浓度呈现良好的线性关系,可以监测较低浓度水平的铜离子。

A reactive copper ion fluorescence probe 1 with weak fluorescence signal is constructed based on naphtho-2-hydrogen-indole derivatives through simple reduction reaction.Its structure is characterized by ¹H-NMR and MALDI-TOF MS.The results show that copper ion can oxidize N-ethyl-2-hydrogen-indole unit in probe 1 into n-ethyl-indole quaternary ammonium salt unit,prolongs the conjugation system of probe 1 molecule and generates excellent changes in optical properties.Probe 1 has good selectivity for copper ions and is not interfered by other cationic analytes.Under weak alkaline conditions,probe 1 recognizes copper ions very quickly,and the color of the solution changes significantly.It can be applied to "naked eye" to identify copper ions in complex environments because probe 1 can recognize copper ions very quickly under weak alkaline conditions and make the color of solution change obviously.After copper ion is gradually added into the solution of probe 1,the fluorescence signal is gradually enhanced,and the change of fluorescence intensity shows a good linear relationship with the concentration of copper ion,which can monitor the copper ion at a lower concentration level.