Controllable nanoscale excitonic systems allow for the realization of artificial light harvesting, molecular computing, and imaging. While natural light-harvesting systems achieve functionality through precise chromophore placement within the protein scaffold, these principles have been challenging to emulate in synthetic systems. DNA origami has emerged as a unique architecture for generating chromophore containing excitonic constructs, as it allows    for nanometer precision over distances and geometries. Here we use DNA-chromophore assemblies to produce excitonic circuitry with facile control over chromophore position and orientation of monomers, dimers, and trimers. Using multidimensional and single-molecule spectroscopy, we show how chromophore placement within a tunable DNA scaffold can be used to control electronic coupling and system-bath coupling independently. With this platform, we demonstrate that coupling between chromophores and their surrounding environment can enhance energy transfer efficiency, highlighting the role of environmental fluctuations in mediating exciton transport. Collectively, these constructs establish a framework for controllable molecular photophysics that may be extended  to programmable light harvesting and molecular electronics.

Engineering exciton dynamics with DNA nanostructures

ACS Spring 2022

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