DNA-functionalized Au nanoparticles (AuNPs) have been intensively exploited as programmable atom equivalents (PAEs) for the self-assembly of molecule-like structures. However, it remains challenging to build hierarchical PAE assemblies via discrete DNA bonds at different levels. Here, we report a strategy to program DNA bond length and bond energy on PAEs using DNA encoders carrying consecutive adenines (polyA). On AuNPs, we built three types of DNA motifs with different topologic configurations, which can form bonds for PAE self-assembly. By small-angle X-ray scattering (SAXS) analysis, we found that the bond length and flexibility between the coupled PAEs can be tuned by programming the bond structure. We also found that these bonds show different bond energies and thus differ, depending on their topologic configuration, leading to different PAE assembly efficiencies. We demonstrated that the bonds at different levels can be arranged in different directions on one nanoparticle, leading to asymmetric PAEs that allow ionic strength-controlled hierarchical assembly of multiparticle structures. This programmable bonding system may provide a new route for building complex plasmonic superstructures.

DNA功能化的Au纳米颗粒（AuNPs）已被广泛地用作可编程原子当量（PAE），用于分子状结构的自组装。然而，通过不同水平的离散DNA键构建分级PAE组件仍然具有挑战性。在这里，我们报告了一种策略，该方法使用携带连续腺嘌呤（polyA）的DNA编码器对PAE上的DNA键长度和键能量进行编程。在AuNP上，我们构建了三种具有不同拓扑结构的DNA基序，它们可以形成PAE自组装的键。通过小角度X射线散射（SAXS）分析，我们发现可以通过对键结构进行编程来调整耦合PAE之间的键长和挠性。我们还发现，这些键表现出不同的键能，因此，取决于它们的拓扑结构，导致不同的PAE组装效率。我们证明了不同水平的键可以在一个纳米粒子上以不同的方向排列，从而导致不对称的PAE，从而允许离子强度控制的多粒子结构的分层组装。这种可编程的键合系统可以为构建复杂的等离子体超结构提供新的途径。