Multiplicative Amplification with Singlet Oxygen and Conjugated Polymers for Bioanalytical Applications

用于生物分析应用的单线态氧和共轭聚合物的倍增扩增

• 批准号: 1305832
• 负责人: Samuel Thomas
• 金额: $ 36万
• 依托单位: Tufts University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1305832&HistoricalAwards=false
• 关键词: Multiplicative; Amplification; Singlet; Oxygen; Conjugated

With support from the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry, Professor Samuel Thomas at Tufts University and his group will develop a new approach to signal amplification in fluorescent assays. Fluorescent sensors and assays are a key set of technologies in analytical science, and amplification of fluorescent response to a specific molecule or other stimulus is critical to the required high sensitivity of many technologies such as ELISA. There is a need, however, to develop new approaches that improve performance through increased quantitative accuracy, robustness in challenging environments, and reduced false positives and negatives. The objective of this project is to test the hypothesis that combining two forms of amplification: 1) chemical amplification of singlet oxygen (1O2) through photosensitization, and 2) light harvesting and exciton mobility will yield multiplicatively amplified fluorescent response that is useful in bioanalytical applications. The group will pursue the following two objectives to test their central hypothesis: 1) Demonstrate multiplicative amplification of fluorescence response of conjugated polymers substituted with traps that react with singlet oxygen, and 2) Use singlet oxygen-responsive polymers to detect target biomolecules at 1.0 pM or lower with high selectivity using sandwich assays. Successful realization of this approach would yield a unique and useful combination of features, such as a ratiometric response and the lack of a requirement for a large enzyme label, which overcomes limitations of current approaches and is potentially useful across a range of analytical applications. The broader impacts of the proposed work will be twofold: 1) a new method for amplifying fluorescent signal has the capability to improve to experimental techniques that rely on sandwich assays such as analysis of clinical samples and high-throughput drug discovery; 2) a program that integrates this research in organic photochemistry with demonstrations and experiments at Bunker Hill Community College, with which Prof Thomas already has a working relationship.Signal amplification?processes that convert a small quantity of sample into a comparatively large readout?are an underlying key to the high sensitivity of modern sample analysis both in the clinic and in the field, in applications such as analysis of DNA or proteins by fluorescence. Limitations of current gold standard methods of amplification, however, are preventing the development of next-generation technologies that can detect targeted molecules at lower levels with reduced false positives and false negatives, especially outside the clinic, where there is a lack of control over environmental conditions. By combining two known methods of signal amplification with specially designed fluorescent materials, this proposed interdisciplinary research will yield a new approach to amplifying fluorescent signal that will be generally useful in a range of bioanalytical applications. Advantages of this approach over state-of-the-art technologies include 1) a more robust readout method of fluorescent signal, 2) no requirement for large enzyme labels, which can cause problems with both stability and sensitivity of an assay, to achieve amplification, and 3) increased sensitivity due to the combination of two forms of amplification. In addition to the benefit to society that such research achievements would provide, the group will also integrate their research into an outreach program at Bunker Hill CC, a nearby community college in Boston where 80% of the students belong to minority groups and over 50% are women, to develop experiments and demonstrations to give students hands-on experience with photochemistry, including using materials they develop in the research.

在化学系化学测量和成像(CMI)计划的支持下，塔夫茨大学的Samuel Thomas教授和他的团队将开发一种在荧光分析中进行信号放大的新方法。荧光传感器和分析方法是分析科学中的一套关键技术，而放大对特定分子或其他刺激的荧光反应对于许多技术(如ELISA)所需的高灵敏度至关重要。然而，需要开发新的方法，通过提高定量准确性、在具有挑战性的环境中的稳健性以及减少假阳性和假阴性来改善性能。这个项目的目的是检验两种放大形式相结合的假设：1)通过光敏化对单线态氧(1O2)进行化学放大，以及2)光捕获和激子迁移率将产生在生物分析应用中有用的倍增放大的荧光反应。该小组将追求以下两个目标来验证他们的中心假设：1)展示用与单线态氧反应的陷阱取代的共轭聚合物的荧光反应的倍增放大，以及2)使用单线态氧响应聚合物以高选择性使用夹心法在下午1点或更低检测目标生物分子。这种方法的成功实现将产生独特和有用的特征组合，例如比率响应和不需要大的酶标记，这克服了目前方法的局限性，在一系列分析应用中潜在地有用。拟议工作的更广泛影响将是双重的：1)一种放大荧光信号的新方法有能力改进依赖于三明治分析的实验技术，如临床样本分析和高通量药物发现；2)将这项有机光化学研究与邦克希尔社区学院的示范和实验相结合的项目，托马斯教授已经与该学院建立了合作关系。信号放大-将少量样本转化为相对较大的读数的过程-是现代样本分析在临床和现场高灵敏度的关键，例如荧光分析DNA或蛋白质。然而，目前金标准扩增方法的局限性阻碍了下一代技术的发展，这种技术可以在较低水平检测靶向分子，减少假阳性和假阴性，特别是在临床之外，那里缺乏对环境条件的控制。通过将两种已知的信号放大方法与特殊设计的荧光材料相结合，这项拟议的跨学科研究将产生一种新的放大荧光信号的方法，这将在一系列生物分析应用中普遍有用。与最先进的技术相比，这种方法的优势包括1)更强大的荧光信号读出方法，2)不需要大的酶标记来实现扩增，这可能会导致分析的稳定性和灵敏度的问题，以及3)由于两种形式的扩增的组合而提高了灵敏度。除了这些研究成果将为社会带来的好处外，该小组还将把他们的研究整合到波士顿附近的社区大学邦克山CC的一个推广项目中，该学院80%的学生属于少数族裔群体，超过50%是女性，以开发实验和演示，让学生亲身体验光化学，包括使用他们在研究中开发的材料。