Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, USA.
J Phys Chem A. 2010 Nov 4;114(43):11567-75. doi: 10.1021/jp107116d.
We designed and synthesized three compounds incorporating a BODIPY fluorophore and an oxazine photochrome within the same molecular skeleton and differing in the nature of the linker bridging the two functional components. The [1,3]oxazine ring of the photochrome opens in less than 6 ns upon laser excitation in two of the three fluorophore-photochrome dyads. This process generates a 3H-indolium cation with a quantum yield of 0.02-0.05. The photogenerated isomer has a lifetime of 1-3 μs and reverts to the original species with first-order kinetics. Both photochromic systems tolerate hundreds of switching cycles with no sign of degradation. The visible excitation of the dyads is accompanied by the characteristic fluorescence of the BODIPY component. However, the cationic fragment of their photogenerated isomers can accept an electron or energy from the excited fluorophore. As a result, the photoinduced transformation of the photochromic component within each dyad results in the effective quenching of the BODIPY emission. Indeed, the fluorescence of these photoswitchable compounds can be modulated on a microsecond time scale with excellent fatigue resistance under optical control. Thus, our operating principles and choice of functional components can ultimately lead to the development of valuable photoswitchable fluorescent probes for the super-resolution imaging of biological samples.
我们设计并合成了三种化合物，它们在同一个分子骨架内结合了 BODIPY 荧光团和恶嗪光致变色体，并且在连接两个功能组件的键的性质上有所不同。在三种荧光团-光致变色体偶联物中的两种中，光致变色体的[1,3]恶嗪环在激光激发下不到 6 纳秒内打开。这一过程生成量子产率为 0.02-0.05 的 3H-吲哚翁阳离子。光致异构化产物的寿命为 1-3 μs，以一级动力学恢复为原始物种。这两个光致变色体系可以耐受数百次开关循环，没有降解的迹象。偶联物的可见激发伴随着 BODIPY 组件的特征荧光。然而，光致异构化产物的阳离子片段可以从激发态荧光团接受电子或能量。结果，每个偶联物中光致变色组件的光诱导转化导致 BODIPY 发射的有效猝灭。事实上，这些光致开关化合物的荧光可以在微秒时间尺度上进行调制，并且在光学控制下具有出色的抗疲劳性。因此，我们的工作原理和功能组件的选择最终可以为生物样品的超分辨率成像开发有价值的光致开关荧光探针。
