水溶性七甲川吲哚菁染料的合成及其在含CTAB溶液中的光谱研究

Research on synthesis and spectral properties in surfactant CTAB of water-soluble heptamethine cyanine dye

本文合成并表征了一种水溶性七甲川吲哚菁染料,测试了染料在不同溶剂和不同浓度的表面活性剂十六烷基三甲基溴化铵(CTAB)中的吸收和荧光光谱性质。结果表明:染料的最大吸收和荧光发射光谱值(乙醇中)分别是796nm和813nm。随着溶剂的黏度增大,染料的荧光强度逐渐减弱。CTAB形成胶束前,随着CTAB浓度的增大,染料的吸收和荧光发射光谱先减小至完全消失;形成胶束后,随着CTAB浓度的增大,染料的吸收和荧光发射光谱又迅速增大,同时最大吸收和最大荧光发射波长发生了红移。这种荧光突变行为为CTAB的胶束形成提供了直观的指示,可据此建立一种测定其CMC的简单的近红外荧光方法。

A heptamethine indocyanine dye with good water-solubility was synthesized and characterized in this paper.Spectral properties in different solvents and different concentrations of CTAB was measured,and it showed that the maximum of absorbance and emission（in ethanol） were 796nm and 813nm respectively.Fluorescence intensity of the dye became weak along with the increased viscosities of the solvents.Before the formation of micelles,with the increasing concentration of CTAB,the absorbance and fluorescence spectra of the dye decreased and then disappeared.After the formation of micelles,the absorbance and fluorescence spectra of the dye abruptly enhanced.Meanwhile,maximum of absorbance and emission spectra was red shifted.This fluorescence mutation gives a direct indication for the micelle forming process and provides a simple and near infrared method for the determination of the critical micelle concentration of the surfactant.