The solubilized form of aluminum, Al3+, is present under acid soil conditions and toxic to both animals and plants. Detecting and quantifying Al3+ is vital for both chemistry and biology. A new Schiff-based fluorescent turn-on sensor (probe L) for the selective detection of the Al3+ 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 L exhibited an excellent selective and sensitive response to the Al3+ ion over other metal ions in DMSO-H₂O (1:9 v/v). Fluorescence quantification revealed that probe L was promising for the detection and accumulation of Al3+. Treating rice seedlings with Al3+ at 25⁻200 μM inhibited their growth. Al3+ treatment produced reactive oxygen species in rice roots. Practical applications of the fluorescent probe for the quantification of Al3+ in water samples and rice seedlings are demonstrated. Detecting the Al3+ ion with the probe L is easy and a potential alternative to existing analytical methods. The method can be used for detecting the Al3+ content of aqueous solution and plant systems. The novel fluorescent probe L has good potential for monitoring Al3+ content in the environment and biological systems.
Keywords: aluminum; fluorescence; rice seedlings.