荧光偏振关联光谱用于单分子动力学特性的研究

Single Molecule Dynamics Measurement by Using Fluorescence Correlation Spectroscopy

本文以SR单分子作为荧光探针,利用两个正交偏振探测通道的荧光偏振关联函数分别测量聚合体薄膜表面与薄膜内部的动力学特性。分析发现薄膜表面的单分子正交偏振的荧光具有反关联特性,荧光偏振互关联函数反映了聚合体薄膜表面的转动动力学特性,测量了单分子转动再取向的特征时间。相应镶嵌在薄膜内部的荧光分子受到环境的束缚,转动自由度低。

In this paper, the dynamics of polymer surface and its interior are measured by using fluorescence correlation spectroscopy with the SR dye molecules as optical probs. It is found that there are the anti-correlated characteristics to the orthogonal polarization of single molecules fluorescence when the SR molecules are absorbed onto the PMMA surface. It is presented directly that the rotational dynamics of the polymer surface is revealed by the cross-correlation function, and the rotational time is measurement. Accordingly, the molecules embedded inside the polymer film are restricted by the surrounded environment and have low rotational freedom degree.