Crystallization of DNA-coated colloids

• Published in: Nature communications 2015-06, Vol.6 (1), p.7253-7253, Article 7253
• Main Authors: Wang, Yu, Wang, Yufeng, Zheng, Xiaolong, Ducrot, Étienne, Yodh, Jeremy S., Weck, Marcus, Pine, David J.
• Format: Article
• Language: English
• Subjects: 639/301/357/354; 639/301/923/966; 639/301/930/1032; 639/638/298/923/916; Colloids - chemistry; Crystallization; Diffusion; DNA - chemistry; Flow Cytometry; Humanities and Social Sciences; Microspheres; multidisciplinary; Science; Science (multidisciplinary); Temperature
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8253

DNA-coated colloids hold great promise for self-assembly of programmed heterogeneous microstructures, provided they not only bind when cooled below their melting temperature, but also rearrange so that aggregated particles can anneal into the structure that minimizes the free energy. Unfortunately, DNA-coated colloids generally collide and stick forming kinetically arrested random aggregates when the thickness of the DNA coating is much smaller than the particles. Here we report DNA-coated colloids that can rearrange and anneal, thus enabling the growth of large colloidal crystals from a wide range of micrometre-sized DNA-coated colloids for the first time. The kinetics of aggregation, crystallization and defect formation are followed in real time. The crystallization rate exhibits the familiar maximum for intermediate temperature quenches observed in metallic alloys, but over a temperature range smaller by two orders of magnitude, owing to the highly temperature-sensitive diffusion between aggregated DNA-coated colloids. DNA-coated colloids have failed to achieve their promise of programmable self-assembly because they stick to each other like Velcro. Here Wang et al. overcome this problem by making clickable smooth colloids that are coated with short single-stranded DNA at high density.