Harnessing Amplified Fluorescence Resonance Energy Transfer in Conjugated Polymer Nanoparticles

利用共轭聚合物纳米颗粒中放大的荧光共振能量转移

• 批准号: 1464699
• 负责人: Elizabeth Harbron
• 金额: $ 31.9万
• 依托单位: College of William and Mary
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1464699&HistoricalAwards=false
• 关键词: Harnessing; Amplified; Fluorescence; Resonance; Energy

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Elizabeth J. Harbron of the Department of Chemistry at The College of William and Mary will develop highly fluorescent organic nanoparticles for use in applications that require a change in fluorescence in response to a specific stimulus. The nanoparticles are derived from fluorescent conjugated polymers and are doped with stimulus-responsive dyes specific to each application. The interaction between the polymer and the dyes yields an amplified response to the stimulus, which means that it can be detected with lower input light levels and/or with much greater sensitivity than with the dyes alone. The targeted applications include nanoparticles that switch their fluorescence on and off for super-resolution microscopy and nanoparticles that change their fluorescence color and/or intensity to control or detect pH and mercury ions in water. These projects are ideally suited to the training and education of undergraduate and masters students because they involve visually appealing work with highly colored, fluorescent materials as well as the opportunity to work at the interface of physical, organic, and analytical chemistry. This group will continue its efforts to increase representation of underrepresented groups in chemistry through mentoring projects targeted toward women as well as advising and mentoring targeted to other groups traditionally underrepresented in chemistry.Conjugated polymer nanoparticles (CPNs or Pdots) hold exceptional promise as fluorophores for sensing and imaging applications due to their intense fluorescence brightness, high photostability, and colloidal stability in water. Their unique strength is the ability to act as light harvesting units, transferring the excitation energy of numerous chromophores to a small number of low-energy sites by fluorescence resonance energy transfer (FRET). CPNs functionalized with FRET-acceptor dyes exhibit amplified dye emission intensities due to this light harvesting effect. In this work, new CPNs functionalized with stimulus-responsive dyes will be developed. The stimulus-responsive dyes have two molecular forms that interconvert in response to a specific stimulus, but only one form can act as a FRET acceptor for the CPNs. Thus, the stimulus induces modulation of fluorescence intensity or color by activating/deactivating FRET. The sensitivity of the stimulus response is substantially increased in the CPNs as compared to the dye alone due to amplified FRET. Optimization of the energy transfer processes in dye-functionalized CPNs will be explored in the following systems: 1) photoactivated CPNs that undergo off-on photoswitching in response to visible light, 2) CPNs that can simultaneously photomodulate pH and provide fluorescence readout, and 3) CPNs that provide ratiometric detection of pH and of mercury ions in completely aqueous environments.

在这个由化学部化学结构，动力学机制B计划资助的项目中，威廉和玛丽学院化学系的Elizabeth J. Harbron教授将开发高荧光有机纳米颗粒，用于需要响应特定刺激而改变荧光的应用。 这些纳米颗粒来源于荧光共轭聚合物，并掺杂有针对每种应用的刺激响应染料。 聚合物和染料之间的相互作用产生对刺激的放大响应，这意味着它可以用较低的输入光水平和/或比单独使用染料高得多的灵敏度来检测。 目标应用包括纳米颗粒，其切换其荧光打开和关闭，用于超分辨率显微镜和纳米颗粒，其改变其荧光颜色和/或强度，以控制或检测水中的pH和汞离子。 这些项目非常适合本科生和硕士生的培训和教育，因为它们涉及具有高度彩色荧光材料的视觉吸引力的工作，以及在物理，有机和分析化学界面工作的机会。 该小组将继续努力，通过针对女性的指导项目，以及针对其他传统上在化学领域代表性不足的群体的建议和指导，增加在化学领域代表性不足的群体的代表性。共轭聚合物纳米颗粒（CPNs或Pdot）由于其强烈的荧光亮度，高的光稳定性和在水中的胶体稳定性，在传感和成像应用中具有特殊的前景。 其独特的优势是能够作为光捕获单元，通过荧光共振能量转移（FRET）将许多发色团的激发能量转移到少量的低能位点。 用FRET受体染料官能化的CPN由于这种光捕获效应而表现出放大的染料发射强度。 在这项工作中，新的CPNs功能化的刺激响应染料将被开发。 刺激响应性染料具有两种分子形式，其响应于特定刺激而相互转化，但只有一种形式可以充当CPNs的FRET受体。 因此，刺激通过激活/失活FRET诱导荧光强度或颜色的调节。与单独的染料相比，由于放大的FRET，CPNs中刺激响应的灵敏度显著增加。 在染料功能化的CPN中的能量转移过程的优化将在以下系统中探索：1）光活化的CPN，其响应于可见光而进行关-开光开关，2）CPN，其可以同时光调节pH并提供荧光读数，以及3）CPN，其提供在完全水性环境中的pH和汞离子的比率检测。