Entropy-Driven Crystallization Behavior in DNA-Mediated Nanoparticle Assembly

详细信息    查看全文

• 作者：Ryan V. Thaner ; Youngeun Kim ; Ting I. N. G. Li ; Robert J. Macfarlane ; SonBinh T. Nguyen ; Monica Olvera de la Cruz ; Chad A. Mirkin
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：August 12, 2015
• 年：2015
• 卷：15
• 期：8
• 页码：5545-5551
• 全文大小：358K
• ISSN：1530-6992

文摘

Herein, we report an example of entropy-driven crystallization behavior in DNA-nanoparticle superlattice assembly, marking a divergence from the well-established enthalpic driving force of maximizing nearest-neighbor hybridization connections. Such behavior is manifested in the observation of a non-close-packed, body-centered cubic (bcc) superlattice when using a system with self-complementary DNA linkers that would be predicted to form a close-packed, face-centered cubic (fcc) structure based solely on enthalpic considerations and previous design rules for DNA-linked particle assembly. Notably, this unexpected phase behavior is only observed when employing long DNA linkers with unpaired 鈥渇lexor鈥?bases positioned along the length of the DNA linker that increase the number of microstates available to the DNA ligands. A range of design conditions are tested showing sudden onsets of this behavior, and these experiments are coupled with coarse-grained molecular dynamics simulations to show that this entropy-driven crystallization behavior is due to the accessibility of additional microstates afforded by using long and flexible linkers.