Pathway-Controlled Formation of Mesostructured all-DNA Colloids and Superstructures

DNA has traditionally been used for programmable design of nanostructures exploiting its sequence-defined supramolecular recognition. However, control on larger lengths scales or even hierarchical materials translating to the macroscale remain difficult to construct. Here, we show that the polymer character of ssDNA can be activated via a nucleobase-specific lower critical solution temperature (LCST), providing unique access to mesoscale structuring mechanisms on larger length scales. We integrate both effects into ssDNA multiblock copolymers coding sequences for phase-separation, hybridization, and functionalization. Kinetic pathway guidance using temperature ramps balances the counteracting mesoscale phase-separation during heating with nanoscale duplex recognition during cooling, yielding a diversity of complex all-DNA colloids with control over internal dynamics and of their superstructures. Our approach provides a facile and versatile platform to add mesostructural layers into hierarchical all-DNA materials. The high density of addressable ssDNA blocks opens routes for applications like gene delivery, artificial evolution, or spatially encoded (bio)materials.