Nonspecific metal-coordination-driven control over higher-order DNA self-assembly

The interactions between chemicals and DNA molecules provide effective regulation tools for dynamically controlling the self-assembly of higher-order DNA nanostructures, which mostly rely on non-covalent π-π stacking, hydrogen bonding and electrostatic interactions. If strong covalent interactions could be introduced as a new regulation strategy, the current control toolbox in DNA nanotechnology would be greatly enriched. Herein, we adopt the silver ion (Ag⁺) to demonstrate a general, versatile coordination-driven regulation strategy for higher-order DNA self-assembly and systematically explore the impacts of Ag⁺ on the assembly and stability of DNA origami and tile-based nanostructures. The kilobase single-stranded scaffold DNA is condensed into uniform nanoparticles by Ag⁺, therefore inhibiting the formation of DNA origami during thermal annealing. Switchable disassembly and re-assembly of DNA tile-based architectures through Ag⁺ and cysteine have been proved. The coordination-driven regulation strategy in this work could in principle be expanded to other metal ions, which might bring unique functions and controls to higher-order DNA self-assembly through metal coordination chemistry.