Programming Dimensional Transitions in DNA Brick Crystals via Interfacial Connectivity.

The precise control of assembly dimensionality and macroscopic structural parameters remains a fundamental challenge in molecular self-assembly. Here, we introduce a programmable strategy to govern the 1D-to-2D dimensional transition and structural width of DNA brick crystals by engineering their connecting interfaces. Using the number of interface connecting strands (Nx) as a quantitative design parameter, we discover a sharp dimensional threshold that is preserved across both honeycomb and square lattices. At Nx ≤ 8, the assembly is strictly confined to one-dimensional nanoribbons; whereas at Nx ≥ 12, lateral coupling activates extended two-dimensional arrays whose structural width increases monotonically with Nx. Thermal and thermodynamic analyses reveal that this sharp threshold behavior is lattice-independent and originates from the size-dependent thermal stability of the laterally connected domains. Our work establishes interfacial connectivity as a predictive handle for the on-demand engineering of self-assembled nanostructures with programmable dimensionality and prescribed widths.