Modeling carbon nanotube-DNA hybrid materials

碳纳米管（CNT）是一种具有独特力学、热学、光学和电子性能的新型材料。在纳米技术和生物医学应用中，碳纳米管和生物结构的整合引起了人们的兴趣。例如，最近发现单链DNA可以与碳纳米管形成螺旋状的杂交体，并有效地分离产生的碳纳米管束。使用功能化的单壁碳纳米管（SWCNTs）可以实现选择性癌细胞破坏，而不会损害正常细胞。SWCNTs也被证明具有检测DNA构象转变的能力。这些技术的发展主要取决于碳纳米管的性质和形成杂化的生物结构以及杂化材料的性质。为了理解和预测碳纳米管的性质，我们需要建立碳纳米管与生物结构之间相互作用的模型。在这项工作中，我们将重点放在理解碳纳米管和DNA之间的主要相互作用上，并通过开发具有几种材料特性的模型将它们结合到一个框架中，这些模型可以封装许多分子细节，并且具有允许在中观尺度上分析许多现象的形式。在这项工作中所研究的相互作用在许多其他纳米生物系统中也很常见。因此，本工作的结果将有利于一类与电子工业、纳米技术和生物医学应用中的纳米生物分子材料工程相关的生物分子/无机系统相互作用问题。

Carbon nanotube (CNT) is a novel material with unique mechanical, thermal, optical and electronic properties. The proposed work is motivated by the emerging interest in the integration of CNTs and biological structures in nanotechnology and biomedical applications. For example, it has be discovered recently that single-stranded DNA can form a hybrid with CNT by wrapping around it in a helical fashion, and provide efficient separation of as-produced CNT bundles. Selective cancer cell destruction has been achieved using functionalized single-walled carbon nanotubes (SWCNTs), without harming normal cells. SWCNTs have also been shown to have the ability of detecting conformational transitions of DNA. Development of these technologies depends critically on the nature of the CNT and the bio-structure forming the hybrid and the properties of the hybrid material. To understand and predict the properties requires us to develop models for the interactions between CNT and bio-structures. In this work, we focus our effort on understanding the major interactions between CNT and DNA, and combining them into one framework by developing models with a few materials properties that can encapsulate much of the molecular details, and are of a form that allows analysis of many phenomena at the meso-scale. The interactions to be studied in this work are also common in many other nano-bio systems. Therefore the results from this work will be beneficial to a class of biological molecule/inorganic system interaction problems related to the engineering of nano-biomolecular material in electronic industry, nanotechnology and biomedical applications.