Metal‐Mediated DNA Nanotechnology in 3D: Structural Library by Templated Diffraction

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. The founding objective of structural DNA nanoscience is demonstrated by using self‐assembled DNA scaffolds for the structure determination of biomolecules by X‐ray diffraction. A structural library of 32 metal‐mediated DNA base pairs (mmDNA) with Ag+, Hg2+, and Au+is assembled and the fundamental design rules for an expanded mmDNA coding system further elucidated, toward the development of molecular electronics and designer nanomaterials.