Energy transfer dynamics and the mechanism of biohybrid photosynthetic antenna complexes chemically linked with artificial chromophores. Issue 40 (21st September 2022)

• Record Type: Journal Article
• Authors: Yoneda, Yusuke; Noji, Tomoyasu; Mizutani, Naoto; Kato, Daiji; Kondo, Masaharu; Miyasaka, Hiroshi; Nagasawa, Yutaka; Dewa, Takehisa
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 40(2022)
• Page Start: 24714
• Page End: 24726
• Publication Date: 2022-09-21
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp02465a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The energy transfer dynamics of the biohybrid photosynthetic antenna complexes were investigated by transient absorption. The mechanism of energy transfer was discussed in terms of the higher-lying exciton state of bacteriochlorophyll aggregates. Abstract : A light-harvesting strategy is crucial for the utilisation of solar energy. In this study, we addressed the expanding light-harvesting (LH) wavelength of photosynthetic LH complex 2 (LH2, from Rhodoblastus acidophilus strain 10050) through covalent conjugation with extrinsic chromophores. To further understand the conjugation architecture and mechanism of excitation energy transfer (EET), we examined the effects of the linker length and spectral overlap integral between the emission and absorption spectra of the energy donor and acceptor pigments. In the former case, contrary to the intuition based on the Förster resonance energy transfer (FRET) theory, the observed energy transfer rate was similar regardless of the linker length, and the energy transfer efficiency increased with longer linkers. In the latter case, despite the energy transfer rate increases at higher spectral overlaps, it was quantitatively inconsistent with the FRET theory. The mechanism of EET beyond the FRET theory was discussed in terms of the higher-lying exciton state of B850, which mediates efficient EET despite the small spectral overlap. This systematic investigation provides insights for the development of efficient artificial photosynthetic systems.