Engineering couplings for exciton transport using synthetic DNA scaffolds

Abstract

Control over excitons enables electronic energy to be harnessed and transported for light harvesting and molecular electronics. Such control requires nanoscale precision over the molecular components. Natural light-harvesting systems achieve this precision through sophisticated protein machinery, which is challenging to replicate synthetically. Here, we introduce a DNA-based platform that spatially organizes cyanine chromophores to construct tunable excitonic systems. We synthesized DNA-chromophore nanostructures and characterized them with ensemble ultrafast and single-molecule spectroscopy and structure-based modeling. This synthetic approach facilitated independent control over the coupling among the chromophores and between the chromophores and the environment. We demonstrated that the coupling between the chromophores and the environment could enhance exciton transport efficiency, highlighting the key role of the environment in driving exciton dynamics. Control over excitons, as reported here, offers a path toward the development of designer nanophotonic devices.