Single-photon absorption and emission from a natural photosynthetic complex.

ABSTRACT: Photosynthesis is generally assumed to be initiated by a single photon^1-3 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 band¹. 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^2-15. 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

SUBMITTER: Li Q 

PROVIDER: S-EPMC10338339 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature