期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2014
卷号：111
期号：42
页码：14995-15000
DOI：10.1073/pnas.1416489111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceThe well-defined base-pairing interactions of DNA allow it to behave as a programmable bond on a nanoparticle scaffold and, when designed properly, these systems are able to form crystals through a process that closely mirrors the formation of atomic crystals. However, DNA-directed nanoparticle crystallization also offers a level of programmability that is not achievable in atomic systems as it enables precise and independent control over many components in a given system. This work focuses on understanding the nature of this DNA "bond," how various parameters affect this bond, and the overall effects as seen through the crystallization behavior of the nanoparticles in an aggregate. If a solution of DNA-coated nanoparticles is allowed to crystallize, the thermodynamic structure can be predicted by a set of structural design rules analogous to Pauling's rules for ionic crystallization. The details of the crystallization process, however, have proved more difficult to characterize as they depend on a complex interplay of many factors. Here, we report that this crystallization process is dictated by the individual DNA bonds and that the effect of changing structural or environmental conditions can be understood by considering the effect of these parameters on free oligonucleotides. Specifically, we observed the reorganization of nanoparticle superlattices using time-resolved synchrotron small-angle X-ray scattering in systems with different DNA sequences, salt concentrations, and densities of DNA linkers on the surface of the nanoparticles. The agreement between bulk crystallization and the behavior of free oligonucleotides may bear important consequences for constructing novel classes of crystals and incorporating new interparticle bonds in a rational manner.
