Sciortino Francesco, Zhang Yugang, Gang Oleg, Kumar Sanat K
Department of Physics, Sapienza Universita' di Roma, Piazzale Aldo Moro, 2, 00185 Rome, Italy.
Center for Functional Nanomaterials, Brookhaven National Laboratories, Upton, New York 11973, United States.
ACS Nano. 2020 May 26;14(5):5628-5635. doi: 10.1021/acsnano.9b10123. Epub 2020 May 12.
We use computer simulations and experiments to study the interactions between nanoparticles (NPs) grafted with self-complementary DNA strands. Each strand ends with a sticky palindromic single-stranded sequence, allowing it to associate equally favorably with strands grafted on the same particle or on different NPs. Surprisingly we find an attractive interaction between a pair of NPs, and we demonstrate that at low temperature it arises purely from a combinatorial-entropy contribution. We evaluate theoretically and verify numerically this entropic contribution originating from the number of distinct bonding patterns associated with intra- and interparticle binding. This entropic attraction becomes more favorable with decreasing inter-NP distance because more sticky ends can participate in making this choice.
我们使用计算机模拟和实验来研究接枝有自互补DNA链的纳米颗粒（NP）之间的相互作用。每条链都以粘性回文单链序列结尾，使其与接枝在同一颗粒或不同NP上的链具有同等良好的结合能力。令人惊讶的是，我们发现一对NP之间存在吸引相互作用，并且我们证明在低温下它纯粹源于组合熵贡献。我们从理论上进行评估并通过数值验证这种源于与颗粒内和颗粒间结合相关的不同键合模式数量的熵贡献。随着NP间距离减小，这种熵吸引变得更有利，因为更多的粘性末端可以参与做出这种选择。
