2026-04-13 基礎生物学研究所,生命創成探究センター,総合研究大学院大学,名古屋工業大学
図１：新たに開発した過渡吸収顕微鏡の模式図（左）と写真（右）。
＜関連情報＞
単一超分子光捕集アンテナの不均一性分解超高速過渡吸収分光法 Heterogeneity-Resolved Ultrafast Transient Absorption Spectroscopy of Single Supramolecular Light-Harvesting Antennas
Shun Arai,Shogo Matsubara,and Toru Kondo
The Journal of Physical Chemistry Letters Published: April 2, 2026
DOI:https://doi.org/10.1021/acs.jpclett.6c00164
Abstract
Photosynthetic light harvesting proceeds rapidly and robustly through precisely arranged pigment molecules. However, the molecular arrangements are not uniform because they exhibit structural heterogeneity among individual complexes and across spatial regions and undergo dynamic fluctuations. Such static and dynamic disorder can substantially perturb excitation dynamics. Here, we report a highly sensitive transient absorption microscope that integrates single-objective absorption microscopy, balanced detection, and lock-in amplification, enabling the quantitative analysis of heterogeneity and temporal fluctuations in excitation dynamics. By analyzing individual chlorophyll-derivative aggregates mimicking photosynthetic light-harvesting antennas, we demonstrated that two kinetic components with nearly identical time constants can be resolved based on differences in their time-constant distributions. We further quantified the photophysical properties of each component, including the absorbance change, fluorescence intensity, fluorescence efficiency, and fluorescence peak intensity ratio. These results establish an analytical framework for excitation dynamics that leverages not only the mean values of time constants but also their distribution profiles.
