An efficient ethylcellulose fluorescent probe for rapid detection of Fe3+ and its multi-functional applications

Fe3+ is the most abundant essential transition metal ion in the human body, plays a vital role in biological and environmental systems. Ethyl cellulose is one of the derivatives of cellulose. Herein, a novel ethylcellulose fluorescent probe EC-HPCB for detecting Fe3+ was prepared by grafting a flavonol derivative as both fluorophore and selective recognition group. The probe exhibited a highly specific "turn-off" fluorescence response to Fe3+, and the fluorescence color changed from yellow to colorless in the presence of Fe3+. The detection limit of EC-HPCB for Fe3+ was 2.65 × 10-7 mol/L, and the response time was as quick as 2 min. The detection mechanism was confirmed by 1H NMR and DFT calculations. Based on the good solubility and processability in organic solvent, EC-HPCB was made into coating and film with favorable fluorescent performances. Furthermore, EC-HPCB probe was successfully applied to monitor Fe3+ in real water samples, and the EC-HPCB-loaded filter paper provided a solid-state platform for detecting Fe3+ by naked eye and fluorescence method.