A Highly Selective and Sensitive Fluorescent Chemosensor for Detecting Al(3+) Ion in Aqueous Solution and Plant Systems

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