DNA origami technique provides a programmable way to construct nanostructures with arbitrary shapes. The dimension of assembled DNA origami, however, is usually limited by the length of the scaffold strand. Herein, we report a general strategy to efficiently organize multiple DNA origami tiles to form super-DNA origami using a flexible and covalent-bound branched DNA structure. In our design, the branched DNA structures (B_n: with a certain number of 2–6 branches) are synthesized by a copper-free click reaction. Equilateral triangular DNA origamis with different numbers of capture strands (T_n: T₁, T₂, and T₃) are constructed as the coassembly tiles. After hybridization with the branched DNA structures, the super-DNA origami (up to 13 tiles) can be efficiently ordered in the predesigned patterns. Compared with traditional DNA junctions (J_n: J₂–J₆, as control groups) assembled by base pairing between several DNA strands, a higher yield and more compact structures are obtained using our strategy. The highly ordered and discrete DNA origamis can further precisely organize gold nanoparticles into different patterns. This rationally developed DNA origami ordering strategy based on the flexible and covalent-bound branched DNA structure presents a new avenue for the construction of sophisticated DNA architectures with larger molecular weights.

中文翻译：

---

基于柔性和共价结合的分支 DNA 结构的超 DNA 折纸的分层组装

DNA折纸技术提供了一种可编程的方式来构建具有任意形状的纳米结构。然而，组装好的 DNA 折纸的尺寸通常受到支架链长度的限制。在这里，我们报告了一种使用灵活且共价结合的分支 DNA 结构有效组织多个 DNA 折纸拼贴以形成超级 DNA 折纸的一般策略。在我们的设计中，分支 DNA 结构（B _n：具有一定数量的 2-6 个分支）是通过无铜点击反应合成的。具有不同捕获链数的等边三角形 DNA 折纸（T _n : T ₁、T ₂和 T ₃) 被构造为组合拼块。与分支 DNA 结构杂交后，超级 DNA 折纸（最多 13 个拼贴）可以有效地以预先设计的模式排序。与通过几个 DNA 链之间的碱基配对组装的传统 DNA 连接（J _n : J ₂ -J ₆，作为对照组）相比，使用我们的策略获得了更高的产量和更紧凑的结构。高度有序和离散的 DNA 折纸可以进一步将金纳米粒子精确地组织成不同的图案。这种基于柔性和共价结合的分支 DNA 结构合理开发的 DNA 折纸排序策略为构建具有更大分子量的复杂 DNA 结构提供了新途径。