Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified β-Cyclodextrin Polymer

• Main Authors: Bhekie B. Mamba, Phendukani Ncube, Rui W. Krause
• Format: Article
• Language: English
• Published: MDPI AG 2011-04-01
• Series: Sensors
• Subjects: fluorescence; chemosensor; chlorinated by-product; azo dye; β-cyclodextrin polymer
• Online Access: http://www.mdpi.com/1424-8220/11/5/4598/

A water soluble azo dye modified β-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs) of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified β-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2,4-dichlorophenol, with a sensitivity factor of 0.35 compared to 0.05 and 0.12 for phenol and 4-chlorophenol, respectively. The stability constants (Ks) of the pollutants were also determined by the Benesi-Hildebrand method to be 2.104 × 103 M−1 for 2,4-dichlorophenol and 1.120 × 102 M−1 for 4-chlorophenol.