A New Schiff Base Based Fluorescent Sensor for Al(III) Based on 2-Hydroxyacetophenone and o-Phenylenediamine

A simple Schiff base (L) based on 2-hydroxyacetophenone and o-phenylenediamine was prepared which acts as an effective fluorescent sensor for Al³⁺ with ca. 9.0 fold enhancement in fluorescence intensity and detection limit 10^-4.3 M. L can quite clearly distinguish Al³⁺ over other metal ions Zn²⁺, Hg²⁺, Cd²⁺, Pb²⁺, Mn²⁺, Mg²⁺, Co²⁺, Ni²⁺, Cu²⁺, Ca²⁺, K⁺, Li⁺, Na⁺ and Fe³⁺. Cyclic voltammogram and square wave voltammogram of L shows a significant change on interaction with Al³⁺. Spectroscopic data and DFT calculations confirm 1:1 interaction between L and Al³⁺ which is reversible with respect to Na₂EDTA.