Anisotropy upgrade for single photon counting

许多化学过程在非常快的时间尺度上发生，比人类眨眼的速度快几千到几百万倍。探针分子在受到辐射时会发光，用来跟踪这些快速的化学反应。探针的荧光强度随时间的变化是通过一种称为单光子计数（spc）的技术来检测的。该提案要求提供资金，以增强spc的能力，使时间分辨荧光各向异性测量成为可能。各向异性实验将提供探测器翻滚速度的信息。这些实验对于Bohne小组获得关于超分子系统大小变化的信息是必不可少的。Moffit小组需要各向异性测量来表征量子点。研究了Hof基团对S100A7蛋白的蛋白-蛋白相互作用的检测，S100A7蛋白是一种新型乳腺癌信号通路的关键成分。各向异性实验按本提案的要求使用偏振器。然而，偏振光会降低我们当前激发源（氢闪光灯）的非偏振光的光强。为此，还需要高强度脉冲二极管激光器（DLs）和脉冲发光二极管（led）。

Many chemical processes occur on very fast time-scales, from thousands to millions of times faster than humans can blink their eyes. Probe molecules, which light up when irradiated, are used to follow these fast chemical reactions. The change of the probe's fluorescence intensity with time is detected with a technique called single photon counting (spc). This proposal requests funds to enhance the capability of the spc to enable time-resolved fluorescence anisotropy measurements. Anisotropy experiments will provide information on how fast probes tumble. These experiments are essential for the Bohne group to obtain information on the changes in sizes of supramolecular systems. The Moffit group needs anisotropy measurements to characterize quantum dots. The detection of protein-protein interactions is studied in the Hof group on the protein S100A7, which is a key component of a novel breast cancer signaling pathway. Anisotropy experiments use polarizers as requested in this proposal. However, the polarizers will decrease the light intensity of the non-polarized light of our current excitation source (hydrogen flash lamp). For this reason, high intensity pulsed diode lasers (DLs) and pulsed light emitting diodes (LEDs) are also requested.