ESIPT-based fluorescence 'turn-on' sensor for selective detection of Al³⁺ ion

1'-hydroxy-2'-acetonaphthone (HAN), a well-known ESIPT probe, served as a simple, highly selective, and sensitive chemo sensor towards Al³⁺ ion. This probe displayed dramatically high ~120 folds fluorescence enhancement upon complexing with Al³⁺, and the detection limit obtained was as low as 42 nM. Furthermore, the spectroscopic and quantum chemical calculations indicated a 1:1 complexation between HAN and Al³⁺ ion. Notably, the present system also illustrates an efficient response towards Al³⁺ in tap water. (author)