A new selective colorimetric and fluorescent chemodosimeter for HSO4(-) based on hydrolysis of Schiff base

Abstract

Two new receptors 1 and 2 were prepared, and their chromogenic and fluorogenic behaviors toward various anions were investigated. Receptors 1 and 2 show exclusive response toward HSO4(-) ion and also distinguish HSO4(-) from other anions by different color changes in aqueous solution (CH3CN/H2O=4/1, v/v). Between them receptor 1 selectively exhibits a pronounced HSO4(-)-induced fluorescence enhancement. The detection limit for the HSO4(-) ion was determined as (0.24±0.03μM). Thus, the receptor 1 can be used as a colorimetric and fluorescent sensor for the determination of HSO4(-) ion. The sensing mechanism has been suggested to proceed via a hydrolysis process. The hydrolysis product has been isolated and further identified by (1)H NMR spectroscopy, ESI-MS analysis and X-ray diffraction.

Keywords: Chromogenic sensor; Fluorescent sensor; Hydrogen sulfate anion; Hydrolysis.