Reversible metamorphosis of hierarchical DNA-inorganic crystals.

Living systems transform their shapes via reversible formation of macromolecular structural complexes, leading to deformations at localized sites. Here we report DNA-inorganic flower-shaped crystals with inscribed deformation modes that enable flowers to shrink and bend reversibly. Template-independent DNA polymerization of pH-responsive and inert blocks tune the hierarchical assembly and spatial localization of DNA within flowers. Experiments and simulations demonstrate that reversible, pH-triggered folding of intraflower DNA strands drives reconfiguration of flowers. By contrast, the subflower localization of these contractile DNA motifs dictates the mode of shape change. As microscale flowers close and open, their nanoscale crystal organization changes reversibly, suggesting that mechanical metamorphosis of flowers is transduced across multiple organizational length scales. The adaptability of flowers to environmental changes activates cascaded biocatalytic reactions and reveals gel-encrypted information. Further variation of the DNA polymer sequence, its subcrystal localization and its reversible folding advances a new class of organic-inorganic shape-shifters.