Near Infrared Fluorescent Single Walled Carbon Nanotubes as Novel Solution Phase Optical Sensing Materials - Proposal Renewal

近红外荧光单壁碳纳米管作为新型溶液相光学传感材料 - 提案更新

• 批准号: 0753020
• 负责人: Michael Strano
• 金额: $ 29.81万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-31 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0753020&HistoricalAwards=false
• 关键词: Near; Infrared; Fluorescent; Single; Walled

0651903Strano, Michael S.Single-walled carbon nanotubes (SWNT) are ideal substrates for optical sensing, due to their large Raman scattering cross-sections and photoluminescence in the near infrared (nIR). The latter occurs where absorption, scattering, and auto-fluorescence from biological media such as whole blood, are minimized. Because the electrons are confined in a one dimensional, cylindrical geometry, carbon nanotubes exhibit intriguing sensitivity to molecular adsorption on their surface, yielding sizable responses for several classes of chemical and biological moieties. The optical modulation of single walled carbon nanotubes is an area that we have pioneered exclusively over past three year project. We were the first to create biomedical implantable sensors for nIR glucose detection (Nature Materials 4, 86, 2005). We demonstrated optical transduction of DNA hybridization (Nano Letters 6, 371, 2006). Recently, in pioneering work, we demonstrated successful operation in live cells for toxic ion detection (Science 311, 508, 2006). In this renewal proposal, we describe a program of continued innovation in this new area by investigating fundamental mechanisms of signal transduction, and using engineering principles to further develop these technologies. The renewal program will answer central questions regarding these systems, and solve major limitations uncovered in our research. We find that many adsorption processes involving DNA/RNA on SWNT possess substantially enhanced thermodynamic barriers over free solution values which translate into exceedingly long transduction times. We show some success in modeling these effects using the theory of polyelectrolyte adsorption on curved surfaces. These models will be utilized to form hypotheses about the influence of length and sequence on adsorption processes to be validated by experiment. Dielectric modulation is a new modality of detection we have uncovered for SWNT. Here, the fluorescence is shifted to a higher energy upon DNA hybridization, and to a lower energy when divalent metal cations are introduced as the surface coverage on the SWNT is changed. The former mechanism is operative only for the (6,5) nanotube for a reason to be uncovered. In this renewal program, we also intend to extend this platform to the measurement of DNA-genotoxins with high sensitivity. We show preliminary data indicating that we can measure the flux of melphalan, a model genotoxic agent, in real time within single living cells. Imagine a universal assay capable of indicating whether an unknown agent in the environment can immediately damage DNA within live cells and tissues. This work will advance the scientific understanding of DNA interactions with other DNA, proteins and polymer adsorbates on carbon nanotube substrates.Intellectual Merit of Proposed Activity: The proposed research renewal will continue to advance the scientific understanding of electron transfer and induced dielectric modulation of 1-D quantum nanotubes using carbon as a model system. The science explored in this work will produce optically-queried sensor molecules with high sensitivity and selectivity for environmentally important analytes. Applications include operation from within strongly scattering, near-infrared transparent media such as the human body. The goal is a new set of engineering tools that have the ability to be used in previously intractable optical media such as whole blood serum, thick tissue and live, unprocessed cell cultures.Broader Impacts of the Proposed Activity: The economic and societal benefits of developing passive, noninvasive sensors for pathogen recognition or medical screening applications are enormous. Imagine being able to screen individuals, clothing and the surrounding environment for small pox contamination by labeling a selective binding agent with a nIR fluorophore sensor as outlined in this proposal and irradiating the suspected person or area with nIR light. This sensing technology will also find applications as injectable, vascular or trans-dermal implants, giving the medical community a remote means of sensing biochemical process at the nanoscale with unprecedented detail. Outreach efforts include active participation with the IMPRINT program at UIUC, where minority students are paired with research labs in the first year of their tenure. The project will also work with W. Hammack on issues of engineering education and societal outreach. An inquiry-based nanotechnology course is also proposed as part of this project.

0651903Strano，Michael S.Single Walled碳纳米管（SWNT）是光学传感的理想底物，因为它们的大拉曼散射横截面和近红外（NIR）中的光致发光。后者发生在最小化生物学培养基（如全血）的吸收，散射和自动荧光。由于电子被限制在一个维，圆柱形几何形状中，因此碳纳米管对其表面上的分子吸附表现出有趣的敏感性，从而对几类化学和生物学部分产生了相当大的反应。单壁碳纳米管的光学调制是我们在过去三年项目中仅开创的领域。我们是第一个创建用于NIR葡萄糖检测的生物医学植入传感器的人（自然材料4，86，2005）。我们证明了DNA杂交的光学转导（Nano Letters 6，371，2006）。最近，在开创性工作中，我们证明了在有毒离子检测的活细胞中成功操作（科学311，508，2006）。在此续签建议中，我们通过研究信号转导的基本机制，并使用工程原理来进一步开发这些技术，描述了该新领域持续创新的计划。续签计划将回答有关这些系统的中心问题，并解决我们研究中发现的主要局限性。我们发现，与自由溶液值相比，SWNT上涉及DNA/RNA的许多吸附过程具有大大增强的热力学屏障，这些溶液值转化为非常长的转导时间。我们使用聚电解质吸附的理论在弯曲表面上的吸附理论来建模这些效果。这些模型将用于形成关于长度和序列对吸附过程的影响的假设，以通过实验验证。介电调制是我们发现SWNT的一种新的检测方式。在这里，在DNA杂交时，荧光转移到较高的能量，当二价金属阳离子被引入时，随着SWNT的表面覆盖率被引入较低的能量。以前的机制仅适用于（6,5）纳米管，原因是要揭开。在这个续签计划中，我们还打算将该平台扩展到具有高灵敏度的DNA生成毒素。我们显示了初步数据，表明我们可以在单个活细胞内实时测量一种模型遗传毒性剂Melphalan的通量。想象一个通用测定，能够指示环境中未知药物是否会立即损害活细胞和组织中的DNA。这项工作将提高对DNA相互作用与其他DNA，蛋白质和聚合物吸附剂的科学理解。纳米管底物对拟议活动的智能优点：拟议的研究更新将继续对电子转移的科学理解，并诱导使用1-D量子纳米管的介电调节，并使用Cabon As A-Coar As Model Manders进行了模型。这项工作中探索的科学将产生具有高灵敏度和对环境重要分析物的选择性的光学引起的传感器分子。应用包括从强烈散射，近红外透明介质（例如人体）的操作。该目标是一套新的工程工具，能够用于以前难以置信的光学介质，例如全血清，较厚的组织和活细胞培养物。拟议活动的影响者的影响：发展被动，非侵入性传感器对病原体识别或医疗筛查应用的经济和社会益处是强大的。想象一下，通过在该提案中概述的NIR荧光团传感器标记选择性结合剂，并通过将选择性结合剂标记，并在此提案中概述了选择性结合剂，并用NIR光照射可疑的人或区域，以筛选个人，衣服和周围环境。这种传感技术还将发现应用程序是可注射，血管或跨多种植入物，从而使医学界以前所未有的细节在纳米级中传感生化过程的遥远方法。推广工作包括积极参与UIUC的烙印计划，在他们任职的第一年，少数族裔学生与研究实验室配对。该项目还将与W. Hammack合作讨论工程教育和社会外展问题。作为该项目的一部分，还提出了基于查询的纳米技术课程。