Naphthalene derived Schiff base as a reversible fluorogenic chemosensor for aluminium ions detection

Schiff base (HNPD) was achieved by reacting 2-hydroxy-1-naphthaldehyde with N-phenyl-o-phenylenediamine in enthanol medium. The spectroscopic analyses were done to establish the formation of Schiff base apparently. Further, synthesized Schiff base conjugate was successfully used as a fluorogenic chemosensor to detect aluminium ions (Al³⁺) with high fluorescence amplification among the other interfering various metal ions. The limit of detection of 0.0248 × 10^-6 M and a binding constant of 6.19 × 10³ M^-1 were obtained by the receptor HNPD for Al³⁺ detection. A high influence of intramolecular charge transfer kinetics was established to realize the selective responsiveness towards Al³⁺ ions. Density functional theory approximation formulated the band energy modulation and localization and delocalization of electron density for the HNPD and Al³⁺ complexation. The developed sensor ultimately inspected on the real soil and water samples and ascertained the practical ability of Al³⁺ ions detection of HNPD chemosensor.