A turn-on fluorescent chemosensor for Zn2+ ions based on antipyrine schiff base

Antipyrine schiff bases 4-(4-hydroxy-3-methoxybenzylideneamino)-2,3-dimethyl-1-phenyl-1,2-dihydropyrazol-5-one (L1) was successfully synthesized and characterized. The complexation behavior of chemosensor with different metal ions including Zn2+ ions in methanolic solution was studied on UV-vis absorption spectra and Photofluorescent spectra. Results showed that the chemosensor (L1) exhibited 55 fold enhancements in fluorescence at 533 nm after adding Zn2+ ions. Such fluorescent responses could be detected by naked eye under UV-lamp. The limit of detection was calculated to be 10(-7) M by titration method. The chemosensor (L1) showed excellent selectivity fluorescent behavior in acidic pH range. The complex solution (L1-Zn2+) exhibited reversibility with EDTA. (C) 2014 Elsevier B.V. All rights reserved.