Molecularly Encoded Regulation of DNA Self-Assembly Crystallization in a Closed Homogeneous Solution System

Self-assembled DNA crystals provide highly ordered three-dimensional frameworks with nanoscale precision for advanced functional materials. However, conventional concentration gradient-driven droplet crystallization in open environments suffers from poorly controlled supersaturation, laborious operation, and heterogeneous products. Here, we report a homogeneous solution strategy for DNA crystal assembly in a closed test tube through base sequence regulation and chemical modification. Rational tuning of the base composition of DNA building blocks and sticky-end 5'-phosphorylation modification enables rapid crystallization within 2 h with relatively uniform crystal sizes. Additionally, phosphorothioate backbone modification enables the assembly of large-sized DNA crystals in a homogeneous environment. Due to the fully enclosed and compositionally uniform reaction environment, this strategy affords highly reproducible control over the crystal size and morphology across batches. This homogeneous solution-based crystallization platform provides a general route to DNA crystalline materials, laying a materials foundation for the construction of functional devices.