The cationic charged water-soluble polyfluorenes containing 2,1,3-benzothiadiazole (BT) units (P1-3) have been synthesized and characterized. These polymers demonstrate intramolecular energy transfer from the fluorene...The cationic charged water-soluble polyfluorenes containing 2,1,3-benzothiadiazole (BT) units (P1-3) have been synthesized and characterized. These polymers demonstrate intramolecular energy transfer from the fluorene units to the BT sites when oppositely charged hyaluronan is added due to the formation of electrostatic complexes, followed by a shift in emission color from blue to green or brown. Upon adding hyaluronidase, the hyaluronan is cleaved into fragments. The relatively weak electrostatic interactions of hyaluronan fragments with polyfluorenes keep their main chains separated and energy transfer from the fluorene units to the BT sites is inefficient, and the polyfluorenes recover their blue emissions. The complexes of conjugated polymers/hyaluronan can be utilized as probes for sensitive and facile fluorescence assays for hyaluronidase. The new assay method interfaces with the aggregation and light harvesting properties of conjugated polymers.展开更多
基金Supported by the "100 Talents" Program of Chinese Academy of Sciencesthe Na-tional Natural Science Foundation of China (Grant Nos. 20725308 & 20721061)973 Project (Grant Nos. 2006CB806200 & 2006CB932100)
文摘The cationic charged water-soluble polyfluorenes containing 2,1,3-benzothiadiazole (BT) units (P1-3) have been synthesized and characterized. These polymers demonstrate intramolecular energy transfer from the fluorene units to the BT sites when oppositely charged hyaluronan is added due to the formation of electrostatic complexes, followed by a shift in emission color from blue to green or brown. Upon adding hyaluronidase, the hyaluronan is cleaved into fragments. The relatively weak electrostatic interactions of hyaluronan fragments with polyfluorenes keep their main chains separated and energy transfer from the fluorene units to the BT sites is inefficient, and the polyfluorenes recover their blue emissions. The complexes of conjugated polymers/hyaluronan can be utilized as probes for sensitive and facile fluorescence assays for hyaluronidase. The new assay method interfaces with the aggregation and light harvesting properties of conjugated polymers.
