A Schiff-base receptor based on phenolphthalein derivate appended 2-furoic hydrazide: Highly sensitive fluorogenic turn on chemosensor for Al3+

Herein, a novel phenolphthalein-derived Schiff base fluorescence probe FF2H has readily been synthesized and applied to be fluorescence ''turn-on. probe for Al3+ sensing in aceto-nitrile (ACN) : HEPES (5.0 mu M, 50/50, v/v, pH = 7). The emission response of the chemo-sensor FF2H toward Al3+ depends on the metal chelation-enhanced fluorescence (CHEF) effect and CHEF prevents C = N isomerisation, the excited state intra-molecular (ESIPT), and PET process of the chemosensor FF2H. FF2H-Al3+ complexation (1:2 stoichiometry) was revealed by Job's method and H-1-NMR titration. The detection limit (LOD) (3s/K) value of FF2H for Al3+ was estimated to be 7.0 nM, demonstrating that the chemosensor FF2H could be employed as a fluorogenic ''turn-on chemosensor to effectively and selectively to recognize Al3+.

Automated summary

A novel phenolphthalein-derived Schiff base fluorescence probe FF2H has been synthesized and utilized for the fluorescence "turn-on" detection of Al3+ in aceto-nitrile: HEPES system. The probe showed high sensitivity and selectivity towards Al3+ detection, making it a promising tool for metal ion sensing.