新罗丹明类荧光探针的合成及对铜(Ⅱ)的检测

Synthesis of a novel rhodamine-based fluorescent probe and the detection of copper(Ⅱ)

以罗丹明B、水合肼、乙二醛与盐酸羟胺为原料,经缩合反应得到新型罗丹明B衍生物2-((3',6'-双(二乙基氨基)-3-氧螺[异吲哚-1,9'-氧杂蒽]-2-基)亚氨基)乙醛肟(RNEO),其结构经核磁和质谱分析表征。通过荧光实验对金属离子进行识别,研究发现,在乙腈/Tris-HCl缓冲水溶液中,RNEO可以作为荧光增强型分子探针选择性识别Cu^(2+),除了Hg^(2+)以外,受常见金属离子(Na^+,K^+,Mg^(2+),Ca^(2+),Ba^(2+),Fe^(3+),Ni^(2+),Cr3+,Cd^(2+),Pb^(2+),Ag^+,Zn^(2+))的干扰较小。探针识别Cu^(2+)后溶液颜色由无色变为紫红色,在365 nm紫外光照射下,探针溶液发出玫瑰红荧光,可以实现裸眼定性检测。建立的荧光测试方法,Cu^(2+)浓度在2.0~15.0μmol/L范围内,此探针的荧光强度与其呈现良好的线性关系。

A novel Rhodamine B derivative 2-（（ 3＇,6＇-bis（ diethylamino）-3-oxospiro [isoindoline-1,9＇-xanthen]-2-yl） imino） acetaldehyde oxime（ RNEO） was synthesized by the condensation reactions of Rhodamine B,hydrazine hydrate,oxalaldehyde and hydroxylamine hydrochloride. Its structure was characterized by NMR and mass spectrum. The recognitions to various metal ions were carried out by the fluorescence experiments. It was found that RNEO compound could be used as a fluorescence enhancement molecular probe for selective recognition of Cu^（2＋）in acetonitrile/Tris-HCl buffer solution. Common metal ions（ Na＋,K＋,Mg^（2＋）,Ca^（2＋）,Ba^（2＋）,Fe3 ＋,Ni^（2＋）,Cr3 ＋,Cd^（2＋）,Pb^（2＋）,Ag＋and Zn^（2＋）） showed almost no interference except for Hg^（2＋）. The color of the solution changed from colorless to purplish red after the recognition of Cu^（2＋）by the probe. Under 365 nm UV light irradiation,the probe solution could emit rose red fluorescence. These color changes could be used for qualitative detecting copper ions by naked eyes. This method in this paper has the advantages of easy operation,good selectivity,high sensitivity and wide linear range. The concentration of Cu^（2＋）in the range of 2. 0 ~ 15. 0 μmol/L showed a good linear relationship with fluorescence intensity of the probe.