A novel oligo(N,O-donor) fluorescent probe possessed the CHEF effect for identification of aluminum ions in the environment

An oligo(N,O-donor) fluorescent probe SAS with high selectivity for Al³⁺ in DMF: H₂O (V/V, 9:1) Tris–HCl solution was designed and synthesized. That is to say, the increase of Al³⁺ activates specific fluorescence of SAS with a strong fluorescent emissive peak at 539 nm, emitting a bright yellow fluorescence, and this long-wavelength fluorescence was characterized by high photostability and low background interference. The lower detection limit for the aluminum ions of the probe SAS was 6.61 × 10^–8 with higher sensitivity & selectivity. Fluorescence titration and density functional theory (DFT) calculations verified the recognition mechanism, and the chelating fluorescence caused by the coordination of metal ion Al³⁺ enhanced the chelation fluorescence enhancement effect. SAS recognizes Al³⁺ with an emission peak at 539 nm, and this long-wavelength fluorescent probe is characterized by high photostability and low background interference. This fluorescent probe SAS was shown to be useful for the detection of Al³⁺ in real water samples with good recoveries.

Graphical abstract

An oligo(N,O-donor) fluorescent probe SAS with high selectivity for Al³⁺ in DMF: H₂O (9:1, V/V) Tris–HCl solution was designed and synthesized. The addition of Al³⁺ excites the yellow fluorescence of SAS, which produces a strong fluorescence emission peak at 539 nm. The probe SAS was highly selective and sensitive for the detection of Al³⁺ with the lowest detection limit of 6.61 × 10^–8. Fluorescence titration and DFT calculations verified the recognition mechanism, and the chelating fluorescence generated by the coordination of metal ions Al³⁺ enhanced the CHEF effect.