A Highly Selective and Sensitive Fluorescent Chemosensor for Detecting Al Ion in Aqueous Solution and Plant Systems.

The solubilized form of aluminum, Al, is present under acid soil conditions and toxic to both animals and plants. Detecting and quantifying Al is vital for both chemistry and biology. A new Schiff-based fluorescent turn-on sensor (probe ) for the selective detection of the Al ion was synthesized by coupling 2-hydroxy-1-naphthaldehyde and 2-aminoisoindoline-1,3-dione, and the structure was characterized by nuclear magnetic resonance spectra. The probe exhibited an excellent selective and sensitive response to the Al ion over other metal ions in DMSO-H₂O (1:9 v/v). Fluorescence quantification revealed that probe was promising for the detection and accumulation of Al. Treating rice seedlings with Al at 25⁻200 μM inhibited their growth. Al treatment produced reactive oxygen species in rice roots. Practical applications of the fluorescent probe for the quantification of Al in water samples and rice seedlings are demonstrated. Detecting the Al ion with the probe is easy and a potential alternative to existing analytical methods. The method can be used for detecting the Al content of aqueous solution and plant systems. The novel fluorescent probe has good potential for monitoring Al content in the environment and biological systems.