Single-molecule spectroscopy and imaging over the decades.
Single-molecule spectroscopy and imaging over the decades.
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DOI：
10.1039/c5fd00149h
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发表时间：
2015
影响因子：
3.4
通讯作者：
Wang Q
中科院分区：
文献类型：
--
作者：
Moerner WE;Shechtman Y;Wang Q
截至2015年，距离首次对凝聚态单分子进行光学探测和光谱分析已经过去了26年。这一科学领域已经远远超出了早期晶体的低温研究范围，涵盖了细胞、聚合物和溶液中的单分子。早期的步骤依赖于低温下固体中分子杂质的不均匀展宽光学吸收曲线的高分辨率光谱。光谱精细结构直接由共振中分子数量的位置相关涨落产生，导致 1989 年使用调频激光光谱达到了单分子极限。在 20 世纪 90 年代初期，人们观察到了单个分子的各种令人着迷的物理效应，包括对单个分子的光进行成像，以及对光谱扩散、光学开关的观察，以及通过简单地调节泵浦激光频率来选择同一焦体积中不同的单个分子的能力。在室温条件下，研究人员表明，可以在溶液中检测到来自单分子的光爆发，从而可以通过多种方法进行成像和显微镜检查。对绿色荧光蛋白单拷贝的研究也发现了一些惊喜，特别是发射器的闪烁和光诱导恢复，这刺激了光可切换荧光蛋白标记的进一步发展。所有这些早期步骤为基于单分子定位和主动控制发射浓度的超分辨率显微镜的发展提供了重要的基础。目前的重点领域包括高精度三维成像的扩展、单分子的定向分析以及通过抑制布朗运动而直接测量溶液中捕获的单分子的光动力学和输运特性。毫无疑问，世界各地许多才华横溢的科学家对单分子进行的大量研究扩展了我们对以前被整体平均隐藏的纳米级和微观机制的了解。
As of 2015, it has been 26 years since the first optical detection and spectroscopy of single molecules in condensed matter. This area of science has expanded far beyond the early low temperature studies in crystals to include single molecules in cells, polymers, and in solution. The early steps relied upon high-resolution spectroscopy of inhomogeneously broadened optical absorption profiles of molecular impurities in solids at low temperatures. Spectral fine structure arising directly from the position-dependent fluctuations of the number of molecules in resonance led to the attainment of the single-molecule limit in 1989 using frequency-modulation laser spectroscopy. In the early 1990's, a variety of fascinating physical effects were observed for individual molecules, including imaging of the light from single molecules as well as observations of spectral diffusion, optical switching and the ability to select different single molecules in the same focal volume simply by tuning the pumping laser frequency. In the room temperature regime, researchers showed that bursts of light from single molecules could be detected in solution, leading to imaging and microscopy by a variety of methods. Studies of single copies of the green fluorescent protein also uncovered surprises, especially the blinking and photoinduced recovery of emitters, which stimulated further development of photoswitchable fluorescent protein labels. All of these early steps provided important fundamentals underpinning the development of super-resolution microscopy based on single-molecule localization and active control of emitting concentration. Current thrust areas include extensions to three-dimensional imaging with high precision, orientational analysis of single molecules, and direct measurements of photodynamics and transport properties for single molecules trapped in solution by suppression of Brownian motion. Without question, a huge variety of studies of single molecules performed by many talented scientists all over the world have extended our knowledge of the nanoscale and microscopic mechanisms previously hidden by ensemble averaging.