Temperature-Cycling-Guided Self-Assembly of DNA-Functionalized Nanoparticles for Avoiding Kinetic Traps.

Area of Science:

• Nanotechnology
• Materials Science
• Biophysics

Background:

• Self-assembly of DNA-functionalized gold nanoparticles is crucial for nanomaterials.
• Kinetic traps caused by strong interparticle forces lead to structural defects and hinder efficient assembly.

Purpose of the Study:

• To develop a novel temperature-cycling strategy to overcome kinetic traps in nanoparticle self-assembly.
• To enhance the formation of defect-free nanoparticle crystals.

Main Methods:

• Theoretical modeling and coarse-grained molecular dynamics simulations.
• Experimental validation of the proposed temperature-cycling strategy.
• Reversible modulation of DNA hydrogen bonding via temperature changes (T_high/T_low).

Main Results:

• The temperature-cycling strategy effectively perturbs defect regions by providing periodic energy input.
• High temperatures allow particles to escape metastable states and reorganize.
• Low temperatures promote hydrogen bond reformation and defect reorganization, leading to defect-free crystals.

Conclusions:

• The developed nonequilibrium pathway efficiently guides nanoparticle self-assembly across free energy barriers.
• This strategy enables the formation of highly ordered, defect-free DNA-gold nanoparticle crystals.
• The approach has potential applications in other self-assembly systems facing kinetic trap challenges.