Probing Forster and dexter energy-transfer mechanisms in fluorescent conjugated polymer chemosensors
Probing Forster and dexter energy-transfer mechanisms in fluorescent conjugated polymer chemosensors
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DOI：
10.1021/jp0301406
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发表时间：
2004-02-05
影响因子：
3.3
通讯作者：
Jones, WE
中科院分区：
文献类型：
--
作者：
Murphy, CB;Zhang, Y;Jones, WE
在多种过渡金属阳离子（包括 Ni2+、Co2+、Cu2+、Fe2+ 和 Cr6+）存在下，评估了悬垂功能化共轭聚合物化学传感器 (ttp-PPETE) 溶液中的荧光猝灭。发射猝灭的光物理分析揭示了一种静态猝灭机制，该机制表现出与预测的线性行为的强烈正偏差。发现增强的发射猝灭机制与聚合物化学传感器上阳离子分析物的相对负载密切相关。这种行为归因于沿着聚合物主链的快速能量转移。改进的 Stern-Volmer 静态猝灭模型已成功应用，该模型包含考虑不同能量转移机制的能量转移项。根据所涉及的猝灭剂分析物的身份，观察到 ttp-PPETE 猝灭的 Forster 和 Dexter 能量转移增强。对于报告的过渡金属，所有情况下的 Stern-Volmer 常数约为 10(5) M-1。 ttp-PPETE 的光物理表征包括在不存在和存在不同浓度分析物的情况下的吸光度、发射度和单光子计数寿命。
Fluorescence quenching in solutions of a pendant-functionalized conjugated polymer chemosensor (ttp-PPETE) has been evaluated in the presence of a variety of transition metal cations, including Ni2+, Co2+, Cu2+, Fe2+, and Cr6+. Photophysical analysis of the emission quenching revealed a static quenching mechanism that demonstrated strong positive deviations from predicted linear behavior. The enhanced emission quenching mechanism was found to correlate closely with the relative loading of the cationic analytes on the polymer chemosensor. This behavior has been attributed to rapid energy transfer along the polymer backbone. A modified Stern-Volmer static quenching model has been successfully applied that incorporates an energy-transfer term that takes into account different energy-transfer mechanisms. Both Forster and Dexter energy-transfer enhancements were observed for ttp-PPETE quenching depending upon the identity of the quencher analyte involved. Stern-Volmer constants in all cases were on the order of 10(5) M-1 for the transition metals reported. Photophysical characterization for ttp-PPETE includes absorbance, emission, and single-photon counting lifetimes in the absence and presence of varying concentrations of the analytes.