Single-molecule spectral fluctuations at room temperature
Single-molecule spectral fluctuations at room temperature
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DOI：
10.1038/385143a0
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发表时间：
1997-01-09
期刊：
影响因子：
64.8
通讯作者：
Xie, XS
中科院分区：
文献类型：
--
作者：
Lu, HP;Xie, XS
近场（1）和远场（2，3）荧光显微镜的最新进展使得在室温下对单个分子成像并测量其发射（3，4）和激发（5）光谱以及荧光寿命（3，6 -8）成为可能。这些研究揭示了光谱位移（4）和强度波动（6，7），其起源尚不清楚。在这里，我们表明，在光谱中的固定的单染料分子的自发波动发生在两个不同的时间尺度：数百毫秒和透镜秒，表明这些波动有两个不同的活化能，此外，我们看到光诱导的光谱波动重复光激发的单分子。我们认为，所有这些波动可以理解为在分子势能面的亚稳极小值之间的过渡。
RECENT advances in near-field(1) and far-field(2,3) fluorescence microscopy have made it possible to image single molecules and measure their emission(3,4) and excitation(5) spectra and fluorescence lifetimes(3,6-8) at room temperature. These studies have revealed spectral shifts(4) and intensity fluctuations(6,7), the origins of which are not clear. Here we show that spontaneous fluctuations in the spectra of immobilized single dye molecules occur on two different timescales: hundreds of milliseconds and lens of seconds, indicating that these fluctuations have two distinct activation energies, In addition, we see photoinduced spectral fluctuations on repealed photoexcitation of single molecules. We suggest that ail of these fluctuations can be understood as transitions between metastable minima in the molecular potential-energy surface.