Synthesis and characterization of Eu(III)-based coordination complexes of modified d-glucosamine and poly(N-isopropylacrylamide)

A series of novel fluorescent complexes was formed by chelation of the thermosensitive polymers with europium(III) ions. The polymers was synthesized via atom transfer radical polymerization (ATRP), which composed of poly(N-isopropyl acrylamide) (PNIPAM) and 2-amino-2-deoxy-d-glucopyranose(d-glucosamine, GA). The aqueous solutions of the polymers and its Eu(III) complexes exhibited a lower critical solution temperatures (LCSTs), and which were approximately equal to body temperature. The maximum emission intensity of the complexes at 613 nm was enhanced by a factor of approximately 10 relative to that of the corresponding Eu(III) chloride. Cell viability assays suggested that these thermosensitive polymers and Eu(III) complexes showed excellent biocompatibility in vitro.