College of Material Science and Engineering & State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, People's Republic of China.
Nanotechnology. 2020 Apr 3;31(25):255708. doi: 10.1088/1361-6528/ab7de3. Epub 2020 Mar 9.
The specific recognition between DNA and single-walled carbon nanotubes (SWCNTs) has enabled wide applications, especially in the chiral sorting of SWCNTs. However, the molecular recognition mechanism has not been fully understood. In our work, various DNA-SWCNT dispersions were prepared by the ultrasonic dispersion method, and characterized by UV absorption spectroscopy, fluorescence emission spectroscopy, zeta potential measurement, SDBS exchange kinetics and computer simulation. The effect of DNA sequence on the structure and properties of hybrid molecules was analyzed. Data analysis showed that DNA with specific recognition had better dispersion quality of the corresponding SWCNT, which means that higher content of monodispersed SWCNTs was obtained. The high-quality dispersion of the DNA-SWCNT pair was attributed to the stronger binding between DNA and SWCNT, resulting in a tighter conformation of DNA on the SWCNT surface and a larger zeta potential of DNA-SWCNT hybrids. Consequently, DNA-SWCNT dispersions of the recognition pair exhibited better stability against salt and stronger fluorescence emission intensity. However, the correlation between specific recognition and DNA coverage on SWCNT was not observed. This work gives more insight into the recognition mechanism between DNA and SWCNTs.
DNA 与单壁碳纳米管（SWCNT）之间的特异性识别使其得到了广泛的应用，特别是在 SWCNT 的手性分离方面。然而，其分子识别机制尚未被完全理解。在我们的工作中，采用超声分散法制备了各种 DNA-SWCNT 分散体，并通过紫外吸收光谱、荧光发射光谱、Zeta 电位测量、SDBS 交换动力学和计算机模拟进行了表征。分析了 DNA 序列对杂交分子结构和性能的影响。数据分析表明，具有特异性识别能力的 DNA 对相应 SWCNT 的分散质量更好，这意味着获得了更高含量的单分散 SWCNT。DNA-SWCNT 对具有良好的分散性归因于 DNA 和 SWCNT 之间更强的结合力，导致 DNA 在 SWCNT 表面的构象更紧密，以及 DNA-SWCNT 杂化物的 Zeta 电位更大。因此，识别对的 DNA-SWCNT 分散体具有更好的耐盐性和更强的荧光发射强度。然而，并未观察到特异性识别与 DNA 在 SWCNT 上的覆盖之间的相关性。这项工作使我们对 DNA 与 SWCNTs 之间的识别机制有了更深入的了解。
