Cubeddu R, Ramponi R, Liu W Q, Docchio F
Photochem Photobiol. 1989 Aug;50(2):157-63. doi: 10.1111/j.1751-1097.1989.tb04142.x.
Time-gated fluorescence spectroscopy was performed on the tumor localizing fraction (TLF) of HpD in buffer at different concentrations of cationic surfactant. This technique obtains emission spectra with programmable delay relative to the excitation pulse. According to the measured fluorescence decay-time constants (approximately 0.7, approximately 3 and approximately 15 ns) three gates were considered, delayed by 0, 5 and 18 ns, respectively, to evaluate the contribution of the emitting molecular species to the spectra. Simultaneous to these measurements, fluorescence decay waveforms and time-integrated spectra were also detected. In buffer and in detergent micelles the fluorescence spectra are given by the superposition of the emission of the different molecular species present in the solution, and no appreciable interaction among the chromophores is observed. On the contrary, in the pre-micellar range of the surfactant, evidence for the existence of an energy transfer mechanism was found. This effect seems to be related to the configurational state of the TLF polymeric chains and depends on the relative TLF/surfactant concentration.
在不同浓度阳离子表面活性剂存在下，对缓冲液中血卟啉衍生物（HpD）的肿瘤定位部分（TLF）进行了时间分辨荧光光谱分析。该技术可获得相对于激发脉冲具有可编程延迟的发射光谱。根据测得的荧光衰减时间常数（约0.7、约3和约15纳秒），设置了三个门，分别延迟0、5和18纳秒，以评估发射分子种类对光谱的贡献。在进行这些测量的同时，还检测了荧光衰减波形和时间积分光谱。在缓冲液和洗涤剂胶束中，荧光光谱是由溶液中存在的不同分子种类的发射叠加而成的，并且未观察到发色团之间有明显的相互作用。相反，在表面活性剂的预胶束范围内，发现了能量转移机制存在的证据。这种效应似乎与TLF聚合物链的构型状态有关，并取决于TLF/表面活性剂的相对浓度。
