Comparison of optical saturation effects in conventional and dual-focus fluorescence correlation spectroscopy
Comparison of optical saturation effects in conventional and dual-focus fluorescence correlation spectroscopy
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DOI：
10.1016/j.cplett.2008.05.018
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发表时间：
2008-06-27
影响因子：
2.8
通讯作者：
Enderlein, Joerg
中科院分区：
文献类型：
--
作者：
Loman, Anastasia;Dertinger, Thomas;Enderlein, Joerg
本文采用传统的荧光相关光谱（FCS）和最近引入的双焦点荧光相关光谱（2fFCS）对荧光染料Cy5在水溶液中的扩散进行了测量。我们研究了两种方法对激励强度的敏感性。由于Cy5在荧光和非荧光状态之间的光驱动转换，传统的FCS显示出强烈的表观扩散系数依赖于激发强度，而2fFCS几乎没有这种伪影。此外，2fFCS使我们能够获得Cy5扩散系数的第一个精确测量的绝对值。(C) 2008 Elsevier B.V.版权所有
We present diffusion measurements of the fluorescent dye Cy5 in aqueous solutions using conventional fluorescence correlation spectroscopy (FCS) and the recently introduced dual-focus fluorescence correlation spectroscopy (2fFCS). We study the sensitivity of both methods with respect to excitation intensity. Due to the light-driven transitions of Cy5 between fluorescent and non-fluorescent states, conventional FCS shows a strong dependence of the apparent diffusion coefficient on excitation intensity, whereas 2fFCS is virtually free from that artifact. Moreover, 2fFCS allows us to obtain the first precisely measured absolute value for the diffusion coefficient of Cy5. (C) 2008 Elsevier B.V. All rights reserved.