Schiff base fluorescent sensor with aggregation induced emission characteristics for the sensitive and specific Fe³⁺...

An aggregation induced emission based compound ((E)-4-((2-hydroxy-5-methoxybenzylidene)amino)benzoic acid) was synthesized through facile Schiff base condensation and characterized by various spectral techniques. The as-prepared compound represented a typical aggregation induced emission behavior in aqueous solution and exploited as a turn-off fluorescent sensor for Fe³⁺ detection in THF-H₂O system (3:7, v/v) with high sensitivity and selectivity. The mechanism of the fluorescence quenching was intensively studied, which was attributed to both dynamic quenching and inner filter effect. The fluorescence probe displayed a highly broad dynamic response range (0.5-500 μM) for selective detection of Fe³⁺ with a limit of detection of 0.079 μM. The proposed method was successfully employed for detection and quantification of Fe³⁺ in human urine samples and proved to have potential for practical applications in biological field.