Tuning Carbon Nanotube Band Gaps by Guanine Functionalization

William Marsh Rice大学的Robert B. Weisman教授得到了化学系大分子、超分子和纳米化学项目的支持，研究和控制与DNA相连的单壁碳纳米管的特性。这些纳米管是人造纳米材料的一个突出家族，其独特的特性和潜在的用途可以导致新的科学发现和在卫生保健、能源和基础设施安全领域的有用的实际应用。这个项目是基于Weisman和同事发现的一种反应，这种反应将DNA与纳米管结合，形成稳定的混合结构，这种结构具有可控的光学和电子特性。研究人员将通过实验和计算进一步探索这些纳米管- dna杂交体的性质，并研究它们在生物医学传感和量子信息处理方面的应用潜力。除了这些研究目标之外，该项目还将在几个层面上推进科学教育。从事该项目的研究生将获得必要的实践培训，并将培养口头和书面技术交流的技能。参与研究的本科生将获得宝贵的研究经验。Weisman实验室还将在暑期接待高中教师参加一个正在进行的项目，扩大他们的知识，丰富影响数百名高中生的科学课程。该项目将加深我们对单线态O2诱导的鸟嘌呤核碱基与碳纳米管之间独特的共价反应的理解。该反应通过引入密集的浅激子阱阵列来扰乱纳米管的电子结构，这些阱的间距和深度可以通过选择ssDNA寡核苷酸结构来控制。因此，它有可能生产出具有工程带隙的纳米管杂化体。在分子动力学和量子化学计算的支持下，实验将研究1)敏化剂和纳米管之间的相互作用如何影响共价反应；2) DNA与纳米管之间的化学键合；3)杂交种光谱展宽的来源；4)控制功能化程度的参数。研究结果将阐明杂化反应的详细结构和官能化反应的机理。还将确定有效形成所需产品的最佳条件。定制的dna功能化纳米管样品将用于有针对性的合作项目，以进一步探索其特性并探索其在量子光学和生物医学传感方面的可能应用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Professor Robert B. Weisman of William Marsh Rice University is supported by the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry to investigate and control the properties of single-wall carbon nanotubes linked to DNA. These nanotubes are a prominent family of artificial nanomaterials whose unusual properties and potential uses can lead to new scientific discoveries and useful real-world applications in the areas of health care, energy, and infrastructure safety. This project is based on the discovery by Weisman and co-workers of a reaction that bonds DNA to nanotubes to form stable hybrid structures that have controllable optical and electronic properties. The investigators will use experiments and computations to further explore the nature of these nanotube-DNA hybrids and to examine their potential for use in biomedical sensing and quantum information processing. Apart from these research goals, the project will advance science education at several levels. Graduate students working on the project will gain essential hands-on training and will develop skills in oral and written technical communication. Undergraduate students participating in the studies will get valuable research experience. The Weisman lab will also host high school teachers during the summers in an ongoing program that expands their knowledge and leads to enriched science curricula affecting hundreds of high school students. This project will deepen our understanding of the unique covalent reaction between guanine nucleobases and carbon nanotubes induced by singlet O2. This reaction perturbs the nanotube electronic structure by introducing a dense array of shallow excitonic traps whose spacing and depth can be controlled by the choice of ssDNA oligo structure. It thus has the potential to produce nanotube hybrids with engineered band gaps. Experiments supported by molecular dynamics and quantum chemical computations will investigate 1) how interactions between sensitizer and nanotube affect the covalent reaction; 2) the chemical bonding between DNA and nanotube; 3) the source of spectral broadening in the hybrids; 4) the parameters controlling functionalization extent. The results will clarify the detailed structures of the hybrids and the mechanism of the functionalization reaction. Optimal conditions for efficient formation of the desired products will also be identified. Customized DNA-functionalized nanotube samples will be prepared for targeted collaborative projects to further probe their properties and explore possible applications in quantum optics and biomedical sensing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.