芘荧光探针法研究环糊精与有机溶剂的极性微环境性质

基于芘的单体荧光光谱振动结构与其所处环境极性的相关性 ,考察了有机溶剂对环糊精 (α- CD、β-CD)空腔微环境的影响。结果表明 ,在所考察的有机溶剂体系里 ,芘的 I3 / I1 与介电常数呈线性相关 ,可用于探测微环境的极性性质变化规律 ;芘和有机溶剂在疏水驱动力的作用下簇集到 CD周围 ,形成一个有序的有利发光的簇集体系 ,CD与有机溶剂之间存在着协同效应 ,而不是加合效应 ;苯较大地改变了微环境的性质 ,使芘的荧光精细结构消失 ,强度增强。环糊精与有机溶剂间的特殊协同增敏效应和环境的极性有极大的关系。

Effects of Organic Solvents on the Microenvironment of Cyclodextrins by Pyrene as Fluorescent Probe

The effects of organic solvents on the microenvironment of cyclodextrins (CD) cavity were studied based on the relativity between the ratio of intensity of the third vibronic band to that of the first band in pyrene monomer fluorescence spectrum (I_3/I_1) and its environmental polarity. The linearity between the value of I_3/I_1 of pyrene and the dielectric constant indicates that pyrene can be used to probe the polarity changes of microenvironment. Pyrene and organic solvents are aggregated into an organized and assembled system surrounding CD under the hydrophobic action, which is in favor to luminescence. There are cooperative effect between CD and organic solvents and benzene has a great influence on the microenvironment. The special cooperative sensitized effect between CD and organic solvents has a relationship with the polarity of microenvironment.