Novel chitosan-based fluorescent materials for the selective detection and adsorption of Fe3+ in water and consequent bio-imaging applications.

A series of fluorescent materials were synthesized by modification of chitosan (CS) with 4-fluoresceincarboxaldehyde (Fluo) and N-methyl-carbazole-3-aldehyde (Cb). Both L-CS-Fluo and L-CS-Cb feature excellent water-solubility and exhibit highly selective fluorescence response to Fe(3+) in environment and biological fields. The high-molecular weight chitosan-based materials: H-CS-Fluo and H-CS-Cb take on doubled absorptivity compared to free chitosan due to the introduction of fluorescence probes. These modified-probe chitosan materials could be regenerated by treating with EDTA. Meanwhile, monomer probes AG-Fluo and AG-Cb linked by D-glucosamine were also synthesized to explore the binding efficiency.