Exploring Size-Controlled Exciton Evolution Using DNA Libraries

TL;DR

This paper explores using DNA to assemble chromophores for studying electronic interactions, enabling rapid screening of multichromophore systems.

Contribution

A DNA-based method for assembling and screening multichromophore systems with controlled stoichiometry and ordering.

Findings

DNA-directed assembly of up to five π-conjugated chromophores shows charge separation and delocalization.

The library enables on-demand production of chromophore dimers and multimers within hours.

Computational prescreening for π-stacking helps optimize charge transfer in assembled systems.

Abstract

To investigate multichromophore
phenomena, progress traditionally
relies on model covalent dimers for spectroscopic interrogation. Integrating
molecular semiconductors into nucleic acid libraries can enable rapid
screening of multichromophore phenomena. Here, we report DNA-directed
assembly of up to five π-conjugated chromophores that demonstrate
charge separation and electronic delocalization phenomena. We integrate
a range of porphyrins and perylene diimides (PDIs)molecular
semiconducting materials widely used in organic electronic devicesin
DNA, encoding nearest-neighbor assembly through base-sequence programmed
hybridization. In this way, we can assemble multicomponent stacks
with tailored electronic properties from a central chromophore-DNA
library. This allows dimer and multimer production on demand, within
hours, from presynthesized DNA-chromophores for spectroscopic analysis.
We demonstrate the library’s ability to optimize for charge
transfer, computationally prescreening for close π-stacking
as a proxy for large orbital overlap and exchange energy. Our modular
DNA assembly reveals opportunities for rapid development of simple,
bespoke chromophore architectures with stoichiometric chromophore
control and ordering.

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