Novel optical selective chromone Schiff base chemosensor for Al³⁺ ion

A novel Schiff-base fluorescent sensor 7-methoxychromone-3-carbaldehyde-((2′-Benzothiazolylthio)-acetyl) hydrazone (MCAH) was synthesized. The new chemosensor possesses dual PET processes simultaneously introducing by both nitrogen and sulfur donors. Upon binding Al³⁺, a significant fluorescence enhancement with a turn-on ratio over 500-fold was triggered. The detection limit of MCAH for Al³⁺ was 3.19×10⁻⁸ M. - Highlights: • A novel chemosensor based on multiple PET processes was synthesized by a facile one-step reaction. • The sensor exhibits higher sensitivity for Al³⁺ than other metal ions with the detection limit reaching at 10⁻⁸ M level in ethanol. • The probe exhibited high selectivity for Al³⁺ over other metal ions with 500-fold fluorescence enhancement