Nordlund T M, Knox W H
Biophys J. 1981 Oct;36(1):193-201. doi: 10.1016/S0006-3495(81)84723-6.
The fluorescence from a purified, aggregate form of the light-harvesting chlorophyll a/b protein has a lifetime of 1.2 +/- 0.5 ns at low excitation intensity, but the lifetime decreases significantly when the intensity of the 20-ps, 530-nm excitation pulse is increased above about 10(16) photons/cm2. A solubilized, monomeric form of the protein, on the other hand, has a fluorescence lifetime of 3.1 +/- 0.3 ns independent of excitation intensity from 10(14)-10(18) photons/cm2/pulse. We interpret the lifetime shortening in the aggregates and the lack of shortening in monomers in terms of exciton annihilation, facilitated in the aggregate by the larger population of interacting chlorophylls.
在低激发强度下，纯化的聚集体形式的捕光叶绿素a/b蛋白发出的荧光寿命为1.2±0.5纳秒，但当20皮秒、530纳米激发脉冲的强度增加到约10¹⁶光子/平方厘米以上时，寿命会显著缩短。另一方面，该蛋白的可溶单体形式的荧光寿命为3.1±0.3纳秒，与10¹⁴ - 10¹⁸光子/平方厘米/脉冲的激发强度无关。我们根据激子湮灭来解释聚集体中寿命的缩短以及单体中寿命未缩短的现象，在聚集体中，相互作用的叶绿素数量较多，这促进了激子湮灭。
