Water-soluble conjugated polyelectrolyte with pendant glycocluster: Synthesis and its interaction with heparin

A novel fluorescent conjugated polyelectrolyte with pendant glucosamine hydrochloride clusters was prepared through Cu(I)-catalyzed azide/alkyne "click" ligation and Suzuki coupling polymerization. Compared with monosugar-functionalized conjugated polymer, the water-solubility and fluorescence quantum yield of the glycocluster-containing polymer (P-3) were significantly improved. As a glucosamine-containing cationic fluorescent polyelectrolyte, the water-soluble fluorescent polymer can interact with heparin through electrostatic bindings, which induce great fluorescence quenching of P-3 due to the polymer aggregation. Furthermore, upon treatment of the P-3-heparin ensemble with protamine, the fluorescence emission of P-3 recovered since the protamine possesses a competitively strong binding affinity to the heparin and thus results in the release of the fluorescent glycopolymer P-3 from the P-3-heparin ensemble.