Revealing and Engineering Assembly Pathways of 3D DNA Origami Crystals

Area of Science:

• Nanotechnology
• Materials Science
• Biophysics

Background:

• DNA origami enables the creation of complex 3D nanoscale architectures via self-assembly.
• Assembly often relies on thermal annealing, typically requiring slow cooling over days, which limits study and fabrication.
• Understanding factors influencing DNA origami lattice formation is crucial for efficient nanostructure engineering.

Purpose of the Study:

• To investigate key factors influencing DNA origami lattice assembly pathways.
• To significantly reduce the time required for DNA origami crystal formation.
• To apply findings to demonstrate thermal pathway-dependent assembly.

Main Methods:

• Utilized optical and electron microscopy for crystal nucleation and growth evaluation.
• Employed small-angle X-ray scattering (SAXS) for time-temperature-transformation (TTT) mapping.
• Performed single-crystal optical tracking to monitor superlattice formation from the melt.

Main Results:

• Demonstrated a reduction in assembly times by up to nearly 2 orders of magnitude through engineered conditions.
• Showed that DNA origami frame assembly follows classical nucleation and growth theory.
• Established that assembly pathways are dependent on thermal annealing profiles, leading to distinct assemblies.

Conclusions:

• Precise engineering of assembly conditions dramatically accelerates DNA origami framework fabrication.
• Classical nucleation and growth theory provides a framework for predicting and controlling DNA origami superlattice formation.
• Tailoring thermal pathways offers a method to direct the formation of specific nanoscale architectures.