The synthesis of a new aromatic polycarboxylic acid and its property as fluorescence-colorimetric chemosensor

Abstract

In this paper, a new “turn-on” aromatic polycarboxylic fluorescent probe L was designed and synthesized based on 4,4′-diaminobiphenyl-2,2′-dicarboxylic acid and salicylaldehyde. The probe L could not only be used as a fluorescent probe to detect Al3+ ions in various solvents, but also be used to detect Fe3+ ions by naked eyes. The detection limits were 5.34 × 10−8 and 1.38 × 10−6 M, respectively. Job′s plot, 1H NMR titration experiments and ESI mass spectrometry proved that the coordination ratio of L and Al3+ ions was 1:1, and Al3+ ions were coordinated with hydroxyl oxygen atoms on the carboxyl groups of probe L. The mechanism could be deduced as chelation enhanced fluorescence.