梁丽芳，邢 达*，陈同生，裴沂辉
（华南师范大学激光生命科学研究所、暨激光生命科学教育部重点实验室，广东 广州 510631）
摘 要：荧光相关谱（fluorescence correlation spectroscopy, FCS）是对处于热平衡态条件下的荧光分子发出的荧光强度涨落进行时间相关处理的一种单分子检测方法，能够直接测量分子在溶液里的扩散系数和浓度。影响FCS测量扩散系数准确性的因素有分子量子效率，测量时间，样本折射率和温度偏差等。用FCS分别测量溶有荧光染料 罗丹明6G (rhodamine 6G, Rh.6G)和青色素Cy5甘油水溶液的粘滞系数，实验结果表明：荧光分子的量子效率是影响测量准确性的重要因素，要求其每秒发射的光子数目 (photon counts per second， cps)至少达到1 000（photons/sec）。
|
|
Studies on a New Technique of Fluorescence Correlation Spectroscopy
LIANG Li-fang, XING Da*, CHEN Tong-sheng, PEI Yi-hui
(MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science,
South China Normal University, Guangdong Guangzhou 510631, China)
Abstract: Fluorescence Correlation Spectroscopy (FCS), a kind of single molecule technique, performs temporally correlative analysis of spontaneous intensity fluctuation of fluorescence from thermal equilibrium with direct measurements of the diffusion coefficient and the concentration of fluorescence molecules in aqueous solution. Some factors, such as the quantum coefficient, the measurement time, the refractive index of the sample and the temperature deviation , make effects on the measurement accuracy. In the thesis, FCS is used to measure the viscosity of the glycerin-water solution with Rhodamine 6G and Cy5, respectively and the experiment results show that the quantum coefficient plays an important role in the measurement accuracy with 1000 photons/sec as the minimal level.
|
