Polarization-Sensitive Single-Object Microscopy Reveals the Structure of a Synthetic Light-Harvesting Complex

Light-harvesting antennae, abundantly found in nature (e.g., in green algae and bacteria), are renowned for their exceptional efficiency, driven by the dense packing of strongly interacting chromophores. This arrangement facilitates the formation of delocalized Frenkel excitons, which diffuse along the antenna structure to enable efficient energy transfer [1]. Molecular double-walled nanotubes (DWNTs), self-assembled from amphiphilic C8S3 molecules in aqueous environments, serve as an ideal model system for investigating the excitons responsible for this energy transfer. Experimental and theoretical studies have proposed two competing structural models for these DWNTs: the bricklayer (BL) model [2], characterized by layered molecular packing, and the herringbone (HB) model [3], featuring an alternating zigzag molecular arrangement.