Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Soft Matter. 2024 Aug 28;20(34):6723-6729. doi: 10.1039/d4sm00854e.
DNA-coated nanoparticles, also known as programmable atom equivalents (PAEs), facilitate the construction of materials with nanoscopic precision. Thermal annealing plays a pivotal role by controlling DNA hybridization kinetics and thermodynamics, which ensures the formation of intended structures. While various design handles such as particle size, DNA design, and salt concentration influence the stability of the DNA duplexes linking PAEs in a lattice, their influence on the system's melting temperature () often follows complicated trends that make rational tuning of self-assembly challenging. In this work, the denaturant formamide is used to precisely tune the thermal response of PAEs. Our results reveal a clear and predictable trend in the PAEs' response to formamide, enabling rational control over the of a diverse set of PAE systems. Unlike adjustments made through alterations to PAE design or solution parameters such as ionic strength, formamide achieves its temperature shift without impacting the kinetics of assembly. As a result, PAEs can be rapidly crystallized at ambient temperatures, producing superlattices with similar quality to PAE crystals assembled through standard protocols that use higher temperatures. This study therefore positions formamide as a useful tool for enhancing the synthesis of complex nanostructures under mild conditions.
DNA 包覆的纳米颗粒，也被称为可编程原子等价物（PAE），有助于以纳米级精度构建材料。热退火通过控制 DNA 杂交的动力学和热力学起着关键作用，这确保了预期结构的形成。虽然各种设计手段，如粒径、DNA 设计和盐浓度，影响连接 PAE 的 DNA 双链在晶格中的稳定性，但它们对系统熔点（）的影响往往遵循复杂的趋势，使得自组装的合理调谐具有挑战性。在这项工作中，变性剂甲酰胺被用来精确调整 PAE 的热响应。我们的结果揭示了 PAE 对甲酰胺响应的清晰可预测趋势，从而能够对各种 PAE 系统的进行合理控制。与通过改变 PAE 设计或溶液参数（如离子强度）来进行调整不同，甲酰胺可以在不影响组装动力学的情况下实现温度的变化。因此，PAE 可以在环境温度下快速结晶，产生与通过使用较高温度的标准协议组装的 PAE 晶体具有相似质量的超晶格。因此，本研究将甲酰胺作为在温和条件下增强复杂纳米结构合成的有用工具。
