Center for Soft Matter Research, Department of Physics, New York University, New York, NY 10003, USA.
Proc Natl Acad Sci U S A. 2012 Nov 13;109(46):18731-6. doi: 10.1073/pnas.1207356109. Epub 2012 Oct 24.
DNA is increasingly used as an important tool in programming the self-assembly of micrometer- and nanometer-scale particles. This is largely due to the highly specific thermoreversible interaction of cDNA strands, which, when placed on different particles, have been used to bind precise pairs in aggregates and crystals. However, DNA functionalized particles will only reach their true potential for particle assembly when each particle can address and bind to many different kinds of particles. Indeed, specifying all bonds can force a particular designed structure. In this paper, we present the design rules for multiflavored particles and show that a single particle, DNA functionalized with many different "flavors," can recognize and bind specifically to many different partners. We investigate the cost of increasing the number of flavors in terms of the reduction in binding energy and melting temperature. We find that a single 2-μm colloidal particle can bind to 40 different types of particles in an easily accessible time and temperature regime. The practical limit of ∼100 is set by entropic costs for particles to align complementary pairs and, surprisingly, by the limited number of distinct "useful" DNA sequences that prohibit subunits with nonspecific binding. For our 11 base "sticky ends," the limit is 73 distinct sequences with no unwanted overlaps of 5 bp or more. As an example of phenomena enabled by polygamous particles, we demonstrate a three-particle system that forms a fluid of isolated clusters when cooled slowly and an elastic gel network when quenched.
DNA 越来越多地被用作编程微米和纳米尺度颗粒自组装的重要工具。这在很大程度上是由于 cDNA 链的高度特异性热可逆相互作用，当将这些 cDNA 链放置在不同的颗粒上时，已经被用于将精确的配对物结合在聚集体和晶体中。然而，只有当每个颗粒都可以寻址并与许多不同种类的颗粒结合时，功能化 DNA 的颗粒才能真正发挥其在颗粒组装方面的潜力。实际上，指定所有键可以强制形成特定的设计结构。在本文中，我们提出了多色颗粒的设计规则，并展示了单个颗粒，即通过多种不同“口味”功能化的 DNA，能够特异性地识别和结合许多不同的伴侣。我们研究了增加口味数量对结合能和熔点降低的影响。我们发现，单个 2μm 胶体颗粒可以在易于接近的时间和温度范围内与 40 种不同类型的颗粒结合。约 100 的实际限制是由粒子对齐互补对的熵成本以及限制了具有非特异性结合的“有用”DNA 序列数量的限制所设定的。对于我们的 11 个碱基“粘性末端”，没有不需要的 5 个碱基或更多的重叠的情况下，限制是 73 个不同的序列。作为多配偶颗粒所带来的现象的一个例子，我们展示了一个三粒子系统，当缓慢冷却时，该系统形成了孤立团簇的流体，当淬火时，该系统形成了弹性凝胶网络。
