Department of Chemistry, National Taras Shevchenko University of Kyiv, 01601 Kyiv, Ukraine.
Methods Appl Fluoresc. 2016 Jul 28;4(3):034004. doi: 10.1088/2050-6120/4/3/034004.
A new small fluorescent dye based on 3-hydroxybenzo[g]quinolone, a benzo-analogue of Pseudomonas quinolone signal species, has been synthesized. The dye demonstrates interesting optical properties, with absorption in the visible region, two band emission due to an excited-state intramolecular proton transfer (ESIPT) reaction and high fluorescence quantum yield in both protic and aprotic media. Time-resolved fluorescence spectroscopy shows that the ESIPT reaction time is unusually long (up to 8 ns), indicating that both forward and backward ESIPT reactions are very slow in comparison to other 3-hydroxyquinolones. In spite of these slow rate constants, the ESIPT reaction was found to show a reversible character as a result of the very long lifetimes of both N and T forms (up to 16 ns). The ESIPT reaction rate is mainly controlled by the hydrogen bond donor ability in protic solvents and the polarity in aprotic solvents. Using large unilamellar vesicles and giant unilamellar vesicles of different lipid compositions, the probe was shown to preferentially label liquid disordered phases.
一种基于 3-羟基苯并[g]喹啉酮的新型小荧光染料已被合成，它是假单胞菌喹诺酮信号物质的苯类似物。该染料表现出有趣的光学性质，在可见区域有吸收，由于激发态分子内质子转移（ESIPT）反应而有两个带发射，并且在质子和非质子介质中都具有高荧光量子产率。时间分辨荧光光谱表明，ESIPT 反应时间异常长（长达 8 ns），这表明与其他 3-羟基喹啉酮相比，正向和反向 ESIPT 反应都非常缓慢。尽管这些速率常数较慢，但由于 N 和 T 形式的寿命非常长（长达 16 ns），因此发现 ESIPT 反应具有可逆性。ESIPT 反应速率主要受质子溶剂中氢键供体能力和非质子溶剂中极性的控制。使用不同脂质组成的大单层囊泡和巨大单层囊泡，该探针被证明优先标记液体无序相。
