Petrásek Zdenek, Krishnan Madhavi, Mönch Ingolf, Schwille Petra
Institut für Biophysik/BIOTEC, TU Dresden, Dresden, Germany.
Microsc Res Tech. 2007 May;70(5):459-66. doi: 10.1002/jemt.20428.
Fluorescence correlation spectroscopy (FCS) is a very sensitive technique that can be used, e.g., for the measurement of low concentrations and for the investigation of transport of fluorescent molecules. Fluorescence lifetime imaging (FLIM) provides spatially resolved information about molecular fluorescence lifetimes reflecting the interactions of the molecules with their environment. We have applied simultaneous two-photon FCS and FLIM to probe the behavior of fluorescent molecules diffusing in submicrometer silicon oxide channels. Our measurements reveal differences in fluorescence lifetimes compared to bulk solution that result from the effects of confinement and the presence of interfaces. Confinement also affects diffusional characteristics of fluorophores as reflected in fluorescence autocorrelation functions. These possible consequences of both spatial confinement and the presence of interfaces between media with different refractive indices on the diffusion and fluorescence lifetime of molecules in nanostructures are discussed in general.
荧光相关光谱法（FCS）是一种非常灵敏的技术，例如可用于测量低浓度以及研究荧光分子的传输。荧光寿命成像（FLIM）提供有关分子荧光寿命的空间分辨信息，反映了分子与其环境的相互作用。我们应用了同步双光子FCS和FLIM来探测在亚微米氧化硅通道中扩散的荧光分子的行为。我们的测量揭示了与本体溶液相比荧光寿命的差异，这些差异是由限制效应和界面的存在导致的。限制也会影响荧光团的扩散特性，这在荧光自相关函数中有所体现。本文将总体讨论空间限制以及具有不同折射率的介质之间的界面的存在对纳米结构中分子的扩散和荧光寿命可能产生的这些影响。
