Pathway Diversity in the Self-Assembly of DNA-Derived Bioconjugates

The pathway diversity of the self-assembly of amphiphilic DNA-pyrene conjugates is described. The hydrophobic pyrene units drive the self-assembly of the anionic oligomers in an aqueous environment into ribbon-shaped, DNA-grafted supramolecular polymers. Isothermal mixing of two types of sorted ribbons, each of which contains only one of two kinds of complementary oligonucleotides, results in the formation of tight networks. Thermal disassembly of these kinetically trapped networks and subsequent reassembly of the liberated components leads to mixed supramolecular polymers, which now contain both types of oligonucleotides. The scrambling of the oligonucleotides prevents the interaction between ribbons and, thus, network formation. The results show that a high local density of DNA strands in linear arrays favors hybridization among sorted polymers, whereas hybridization among mixed arrays is prevented. The lack of DNA hybridization among mixed ribbons is ascribed to the electrostatic repulsion between identical, hence noncomplementary, oligonucleotides. The findings highlight the importance of kinetically trapped states on the structural and functional properties of supramolecular polymers containing orthogonal self-assembly motifs.