Structure and switching of single-stranded DNA tethered to a charged nanoparticle surface

作     者：赵新军 高志福 Xin-Jun Zhao;Zhi-Fu Gao

作者机构：Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter Physics Yi Li Normal University Yining 835000 China National Laboratory of Solid State Microstructures and Department of Physics Nanjing University Nanjing 210093 China Xinjiang Astronomical Observatory Chinese Academy of Sciences Urumqi 830011 China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2016年第25卷第7期

页      面：269-276页

核心收录：

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 081201[工学-计算机系统结构] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：Project supported by the Joint Funds of Xinjiang Natural Science Foundation China(Grant No.2015211C298) 

主　　题：molecular theory ss DNA tethered to charged nanoparticle surface temperature dependent switching 

摘      要：Using a molecular theory, we investigate the temperature-dependent self-assembly of single-stranded DNA（ss DNA）tethered to a charged nanoparticle surface. Here the size, conformations, and charge properties of ss DNA are taken into account. The main results are as follows： i） when the temperature is lower than the critical switching temperature, the ss DNA will collapse due to the existence of electrostatic interaction between ss DNA and charged nanoparticle surface; ii）for the short ss DNA chains with the number of bases less than 10, the switching of ss DNA cannot happen, and the critical temperature does not exist; iii） when the temperature increases, the electrostatic attractive interaction between ss DNA and charged nanoparticle surface becomes weak dramatically, and ss DNA chains will stretch if the electrostatic attractive interaction is insufficient to overcome the elastic energy of ss DNA and the electrostatic repulsion energy. These findings accord well with the experimental observations. It is predicted that the switching of ss DNA will not happen if the grafting densities are too high.