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Abstract The rational design of molecular electronics remains a grand challenge of materials science. DNA nanotechnology has offered unmatched control over molecular geometry, but direct electronic functionalization is a challenge. Here a generalized method is presented for tuning the local band structure of DNA using transmetalation in metal‐mediated base pairs (mmDNA). A method is developed for time‐resolved X‐ray diffraction using self‐assembling DNA crystals to establish the exchange of Ag⁺ and Hg²⁺ in T:T base pairs driven by pH exchange. Transmetalation is tracked over six reaction phases as crystal pH is changed from pH 8.0 to 11.0, and vice versa. A detailed computational analysis of the electronic configuration and transmission in the ensuing crystal structures is then performed. This findings reveal a high conductance contrast in the lowest unoccupied molecular orbitals (LUMO) as a result of metalation. The ability to exchange single transition metal ions as a result of environmental stimuli heralds a means of modulating the conductance of DNA‐based molecular electronics. In this way, both theoretical and experimental basis are established by which mmDNA can be leveraged to build rewritable memory devices and nanoelectronics. 

Abstract Structural DNA nanotechnology enables the self‐organization of matter at the nanometer scale, but approaches to expand the inorganic and electrical functionality of these scaffolds remain limited. Developments in nucleic acid metallics have enabled the incorporation of site‐specific metal ions in DNA duplexes and provide a means of functionalizing the double helix with atomistic precision. Here a class of 2D DNA nanostructures that incorporate the cytosine‐Ag⁺‐cytosine (dC:Ag⁺:dC) base pair as a chemical trigger for self‐assembly is described. It is demonstrated that Ag⁺‐functionalized DNA can undergo programmable assembly into large arrays and rings, and can be further coassembled with guanine tetraplexes (G4). It is shown that 2D DNA lattices can be assembled with a variety of embedded nanowires at tunable spacing. These results serve as a foundation for further development of self‐assembled, metalated DNA nanostructures, with potential for high‐precision DNA nanoelectronics with nanometer pitch. 

Abstract The DNA tensegrity triangle is known to reliably self‐assemble into a 3D rhombohedral crystalline lattice via sticky‐end cohesion. Here, the library of accessible motifs is expanded through covalent extensions of intertriangle regions and sticky‐end‐coordinated linkages of adjacent triangles with double helical segments using both geometrically symmetric and asymmetric configurations. The molecular structures of 18 self‐assembled architectures at resolutions of 3.32–9.32 Å are reported; the observed cell dimensions, cavity sizes, and cross‐sectional areas agree with theoretical expectations. These data demonstrate that fine control over triclinic and rhombohedral crystal parameters and the customizability of more complex 3D DNA lattices are attainable via rational design. It is anticipated that augmented DNA architectures may be fine‐tuned for the self‐assembly of designer nanocages, guest–host complexes, and proscriptive 3D nanomaterials, as originally envisioned. Finally, designer asymmetric crystalline building blocks can be seen as a first step toward controlling and encoding information in three dimensions. 

Abstract DNA double helices containing metal‐mediated DNA (mmDNA) base pairs are constructed from Ag⁺and Hg²⁺ions between pyrimidine:pyrimidine pairs with the promise of nanoelectronics. Rational design of mmDNA nanomaterials is impractical without a complete lexical and structural description. Here, the programmability of structural DNA nanotechnology toward its founding mission of self‐assembling a diffraction platform for biomolecular structure determination is explored. The tensegrity triangle is employed to build a comprehensive structural library of mmDNA pairs via X‐ray diffraction and generalized design rules for mmDNA construction are elucidated. Two binding modes are uncovered: N3‐dominant, centrosymmetric pairs and major groove binders driven by 5‐position ring modifications. Energy gap calculations show additional levels in the lowest unoccupied molecular orbitals (LUMO) of mmDNA structures, rendering them attractive molecular electronic candidates.