Single-photon absorption and emission from a natural photosynthetic complex.
Single-photon absorption and emission from a natural photosynthetic complex.
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自然光合复合物的单光子吸收和排放。
DOI：
10.1038/s41586-023-06121-5
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发表时间：
2023-07
期刊：
影响因子：
64.8
通讯作者：
Whaley, K. Birgitta
中科院分区：
文献类型：
--
作者：
Li, Quanwei;Orcutt, Kaydren;Cook, Robert L.;Sabines-Chesterking, Javier;Tong, Ashley L. L.;Schlau-Cohen, Gabriela S.;Zhang, Xiang;Fleming, Graham R.;Whaley, K. Birgitta
光合作用通常被认为是由来自太阳的单个光子引发的，太阳作为弱光源，在叶绿素吸收带内每纳米平方每秒最多传递几十个光子。然而，在过去的40年里，大量的实验和理论工作已经探索了光合作用中吸收强、超短激光脉冲后发生的事件。在这里,我们使用单个光子激发聚光2 (LH2)复杂环境条件下的紫色细菌Rhodobacter sphaeroides,包括B800和B850环包含9和18细菌叶绿素分子,分别。B800环的激发导致电子能量在大约0.7 ps的时间内转移到B850环，随后在大约100-fs的时间尺度上快速B850到B850的能量转移和850-875 nm的光发射（参考文献）。。我们利用一个预示的单光子源和巧合计数，建立了B800激发和B850荧光发射的时间相关函数，并证明这两个事件都涉及单光子。我们还发现，每个检测到的荧光光子的先驱者数量的概率分布支持这样的观点，即单个光子在吸收后可以驱动随后的能量转移和荧光发射，从而进一步推动光合作用的初级电荷分离。分析随机模型和蒙特卡罗数值模型捕获了数据，进一步证实了在自然光收集复合体中单光子的吸收与单光子的发射相关。我们利用一个预示的单光子源和巧合计数，建立了B800激发和B850荧光发射的时间相关函数，并证明这两个事件都涉及单光子。
Photosynthesis is generally assumed to be initiated by a single photon from the Sun, which, as a weak light source, delivers at most a few tens of photons per nanometre squared per second within a chlorophyll absorption band. Yet much experimental and theoretical work over the past 40 years has explored the events during photosynthesis subsequent to absorption of light from intense, ultrashort laser pulses. Here, we use single photons to excite under ambient conditions the light-harvesting 2 (LH2) complex of the purple bacterium Rhodobacter sphaeroides, comprising B800 and B850 rings that contain 9 and 18 bacteriochlorophyll molecules, respectively. Excitation of the B800 ring leads to electronic energy transfer to the B850 ring in approximately 0.7 ps, followed by rapid B850-to-B850 energy transfer on an approximately 100-fs timescale and light emission at 850–875 nm (refs. ). Using a heralded single-photon source along with coincidence counting, we establish time correlation functions for B800 excitation and B850 fluorescence emission and demonstrate that both events involve single photons. We also find that the probability distribution of the number of heralds per detected fluorescence photon supports the view that a single photon can upon absorption drive the subsequent energy transfer and fluorescence emission and hence, by extension, the primary charge separation of photosynthesis. An analytical stochastic model and a Monte Carlo numerical model capture the data, further confirming that absorption of single photons is correlated with emission of single photons in a natural light-harvesting complex. Using a heralded single-photon source along with coincidence counting, we establish time correlation functions for B800 excitation and B850 fluorescence emission and demonstrate that both events involve single photons.
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DOI：
10.1073/pnas.1005484107
发表时间：
2010-07-20
影响因子：
11.1
作者：
Panitchayangkoon, Gitt;Hayes, Dugan;Engel, Gregory S.
通讯作者：
Engel, Gregory S.
DOI：
10.1209/0295-5075/1/4/004
发表时间：
1986-02-15
期刊：
EUROPHYSICS LETTERS
影响因子：
--
作者：
GRANGIER, P;ROGER, G;ASPECT, A
通讯作者：
ASPECT, A
影响因子：
19.6
作者：
Piro, N.;Rohde, F.;Eschner, J.
通讯作者：
Eschner, J.
DOI：
10.1073/pnas.1310222110
发表时间：
2013-07-02
影响因子：
11.1
作者：
Schlau-Cohen, Gabriela S.;Wang, Quan;Moerner, W. E.
通讯作者：
Moerner, W. E.
影响因子：
4.4
作者：
Ko, Liwen;Cook, Robert L.;Whaley, K. Birgitta
通讯作者：
Whaley, K. Birgitta