A New Fluorenone-based Turn-on Fluorescent Al3+ Ion Sensor

Abstract

In this paper, we report a turn-on fluorescence sensing of Al³⁺ ion using a new fluorenone derivative. The imino derivative of 2-amino-9-fluorenone and mercapto-2-butanone is synthesized and characterized using IR, NMR, and mass spectral techniques. The fluorescence of the compound shows a large enhancement at the addition of Al³⁺ ions, and other metal ions show insignificant changes of the fluorescence. The stoichiometry and the binding constant of the complex are reported. The detection limit of the Al³⁺ determination by the fluorenone derivative is 5 × 10^–8 M. A visible enhancement of color occurs on illumination of the fluorescent compound – Al³⁺ ion complex.