Inexpensive electronics and software for photon statistics and correlation spectroscopy.
Inexpensive electronics and software for photon statistics and correlation spectroscopy.
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DOI：
10.1119/1.4869188
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发表时间：
2014-07
影响因子：
0.9
通讯作者：
Goldner LS
中科院分区：
文献类型：
--
作者：
Gamari BD;Zhang D;Buckman RE;Milas P;Denker JS;Chen H;Li H;Goldner LS
单分子敏感的显微镜技术和光谱学正在改变生物物理学和材料科学实验室。诸如荧光相关光谱（FCS）和单分子敏感的荧光共振能量转移（FRET）等技术现在在研究实验室中普遍可用，但在教学实验室中却很少见。我们介绍了一些廉价的电子设备和开源软件，它们填补了这一差距，使对生物物理学感兴趣的本科生能够接触到最先进的研究能力。我们讨论了与FCS相关的强度相关函数以及如何从光子到达时间确定它。我们通过使用适合本科教学实验室的FCS测量一种蛋白质的流体动力学半径来展示该系统。这种基于现场可编程门阵列（FPGA）的电子设备易于构建，也适用于更高级的测量，并描述了几种应用。该系统实现了8纳秒的定时分辨率，可以控制多达四个激光源，并可以从多达四个光子计数探测器收集信息。
Single-molecule-sensitive microscopy and spectroscopy are transforming biophysics and materials science laboratories. Techniques such as fluorescence correlation spectroscopy (FCS) and single-molecule sensitive fluorescence resonance energy transfer (FRET) are now commonly available in research laboratories but are as yet infrequently available in teaching laboratories. We describe inexpensive electronics and open-source software that bridges this gap, making state-of-the-art research capabilities accessible to undergraduates interested in biophysics. We include a discussion of the intensity correlation function relevant to FCS and how it can be determined from photon arrival times. We demonstrate the system with a measurement of the hydrodynamic radius of a protein using FCS that is suitable for the undergraduate teaching laboratory. The FPGA-based electronics, which are easy to construct, are suitable for more advanced measurements as well, and several applications are described. As implemented, the system has 8 ns timing resolution, can control up to four laser sources, and can collect information from as many as four photon-counting detectors.