FLUORESCENT POLYMER CHEMOSENSORS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。我们一直在研究一系列新的荧光，共轭聚合物材料，包含多受体组件。多个受体位点通过共轭聚合物（分子线）电子连接，比传统的基于分子的荧光化学传感器表现出更大的灵敏度增益。这些聚合物已被发现在低至4*10-9 m的浓度下对过渡金属离子作出定量反应。我们还开发了一种新的方法来创建通过“开启”荧光机制作出反应的无机/有机杂化聚合物。该混合系统在选择性检测生物铁方面显示出良好的效果。为了更完整地表征荧光猝灭过程的动力学，时间分辨发射和瞬态吸收测量是必要的。鉴于这些聚合物的非线性斯特恩-沃尔默行为，这一点尤为重要，这种行为可归因于聚合物主链上的能量传递动力学和更传统的静态淬火的结合。一个特定的光物理目标将是确定在淬火过程中是否形成电荷转移产物。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have been investigating a new series of fluorescent, conjugated polymer materials that contain polyreceptor assemblies. The multiple receptor sites are electronically connected by the conjugated polymer (molecular wire) and exhibit larg sensitivity gains over more conventional molecule-based fluorescent chemosensors. These polymers have been found to respond quantitatively to transition metal ions at concentrations as low as 4*10-9 M. We have also developed a new method to create inorganic/organic hybrid polymers that respond through a "turn-on" fluorescence mechanism. This hybrid system is showing promising results for the selective detection of biological iron. In order to more completely characterize the dynamics of the fluorescent quenching process, time-resolved emission and transient absorption measurements are necessary. This is particularly important in light of the non-linear Stern-Volmer behavior of these polymers that can be attributed to a combination of energy transfer dynamics on the polymer backbone and more traditional static quenching. A specific photophysical goal will be to identify whether charge transfer products are formed during the quenching process.