DNA as a supramolecular framework for the helical arrangements of chromophores: towards photoactive DNA-based nanomaterials.

Nucleic acids have been emerging as supramolecular structural scaffolds for the helical organization of chromophores in the creation of functional nanomaterials mainly because of the their unique structural features and synthetic accessibility. A large number of chromophores have been successfully incorporated into DNA or RNA as C-nucleosides, as base surrogates or as modified sugars using solid phase phosphoramidite chemistry. Moreover, multiple incorporations yield the helical organization of the chromophores inside or outside the DNA or RNA double helix depending upon the conjugation of the chromophores. Significant photophysical interactions are observed in the chromophore stacks resulting in unique optical properties that are significantly different from the monomer properties. In this feature article, multichromophore labelled nucleic acids are reviewed with special emphasis on the self-assembly induced modulation of the optical properties.