氧气诱导单分子电子转移的动力学特性

Oxygen-Induced Electron Transfer Dynamic Characteristics of Single Molecules

通过测量单分子荧光亮态、暗态持续时间的概率密度统计特性,研究了氧气含量对单分子电子转移动力学特性的影响。在富氧环境下,单分子荧光闪烁由离子态的电子布居引起,呈现幂律分布;在贫氧环境下,单分子荧光闪烁主要源于三重态的电子布居,呈现指数截止型幂律分布;在特定氧气环境下,两种电子转移过程呈现明显的竞争效应,部分单分子荧光闪烁服从幂律分布,其余单分子荧光闪烁服从指数截止型幂律分布。

By measuring the probability density statistical characteristics of the duration time of single molecules fluorescence at on-and off-states, the effect of oxygen concentration on electron transfer dynamic characteristic of single molecules is studied. In the oxygen-rich environment, the fluorescence blinking of single molecules is caused by the electron population of ionic state and presents a power-law distribution. In the oxygen-poor environment, the fluorescence blinking of single molecules mainly stems from the electron population of triplet state and presents an exponential truncated power-law distribution. In the oxygen-specific environment, two kinds of electron transfer processes show an apparent competition effect, where part fluorescence blinking of single molecules follows a powerlaw distribution while the other part follows an exponential truncated power-law distribution.