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

► Both water-soluble materials L-CS-Fluo and L-CS-Cb feature highly selective fluorescence response to Fe3+ in environment and biological fields. ► The water-insoluble chitosan-based materials H-CS-Fluo and H-CS-Cb take on doubled absorptivity compared to free chitosan and could be regenerated by treating with EDTA.