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Melamine is shown to associate with two poly(thymine) strands, forming antiparallel duplexes that can be used for the dynamic assembly of DNA-based nanostructures.

Nanotubular structures made from different materials are being investigated for applications ranging from sensing to drug delivery, but controlling how they interact with ‘cargo’ molecules has proved challenging. Now, the selective uptake, precise positioning and triggered release of gold nanoparticles has been achieved with nanotubes assembled from triangular DNA building blocks.

To mark the occasion of Nature Chemistry turning 10 years old, we asked scientists working in different areas of chemistry to tell us what they thought the most exciting, interesting or challenging aspects related to the development of their main field of research will be — here is what they said.

Incorporating binding sites for metal ions into DNA strands that assemble into well-defined three-dimensional structures has enabled researchers to build metal-nucleic acid cages. There is potential for the geometry, pore size and chemistry of such materials to be easily tuned, which may prove useful for applications in molecular sensing and encapsulation.

DNA nanotubes are attractive building blocks for the assembly of complex arrays. An efficient solid-state synthesis for producing surface-grafted, robust nanotubes has now been devised. Rungs are incorporated in a stepwise manner so that each one is addressable. Using fluorescent tags, the nanotube growth was visualized at the single-molecule level.

DNA nanotubes can potentially act as stiff interconnects, tracks for molecular motors and nanoscale drug carriers. Researchers have now reported a modular approach to DNA nanotube synthesis that can create geometrically well-defined triangular and square tubes. The method allows parameters such as geometry, stiffness and single- or double-stranded character to be tuned, and could provide access to designer nanotubes for a range of applications.

Nature uses out-of-equilibrium systems to control hierarchical assembly. Now, a dissipative chemical system has been shown to slowly release monomer DNA strands from a high-energy reservoir, regulating self-assembly by switching the mechanism of supramolecular polymerization at the single-molecule level. This process heals fibre defects, converting branched, heterogeneous networks into nanocable superstructures.

The combination of dynamic, energy driven folding and growth with structural stiffness and length control is difficult to achieve in synthetic polymer self-assembly. Here the authors show that highly charged, monodisperse DNA oligomers assemble via seeded growth into length-controlled supramolecular fibers during heating.

Assembling defined sequences of DNA is important for many applications, but the synthesis becomes more difficult as the target size increases. Here, the authors report a method for assembling DNA by combining smaller strands, with the final structure determined by the order of addition of the fragments.

The site-specific incorporation of dendritic DNA amphiphiles into a DNA cage controls whether the resultant structures show intermolecular self-assembly or intramolecular assembly. Intramolecular assembly creates a hydrophobic core within the cage that is capable of encapsulating small molecules. These molecules can be released on addition of specific DNA strands.

DNA nanostructures are typically used as molecular scaffolds. Now, it has been shown that they can also act as reusable templates for ‘molecular printing’ of DNA strands onto gold nanoparticles. The products inherit the recognition elements of the parent template: number, orientation and sequence asymmetry of DNA strands. This converts isotropic nanoparticles into complex building blocks.

The field of DNA nanotechnology takes the DNA molecule out of its biological context and uses its information to assemble structural motifs and connect these motifs together. In this Review, a historical account of the field and the approaches used to assemble DNA nanostructures are outlined, followed by a discussion of emerging applications.

Cyanuric acid, a small molecule with three thymine-like faces, reprogrammes the assembly of unmodified poly(adenine) into long fibres with a unique internal structure. The association of adenine and cyanuric acid units into a hexameric rosette motif brings together poly(adenine) triplexes with subsequent cooperative polymerization.

DNA–polymer conjugates are attractive materials that combine the programmability of nucleic acid assembly with polymer functionality. Now, through a DNA cube template, monodisperse polymer particles have been imprinted with several DNA strands in pre-designed orientations— each independently set and addressable. The resulting hybrid particles can further assemble into well-defined, non-centrosymmetric structures.

Complex assembly pathways often involve transient, partly-formed intermediates that are challenging to characterize. Here, the authors present a simple and rapid spectroscopic thermal hysteresis method for mapping the energy landscapes of supramolecular assembly.