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. 2011;11(5):4598-608.
doi: 10.3390/s110504598. Epub 2011 Apr 27.

Fluorescent sensing of chlorophenols in water using an azo dye modified β-cyclodextrin polymer

Phendukani Ncube  1 , Rui W Krause, Bhekie B Mamba
Affiliations

Fluorescent sensing of chlorophenols in water using an azo dye modified β-cyclodextrin polymer

Phendukani Ncube et al. Sensors (Basel). 2011.

Abstract

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 (1)H-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 (K(s)) of the pollutants were also determined by the Benesi-Hildebrand method to be 2.104 × 10(3) M(-1) for 2,4-dichlorophenol and 1.120 × 10(2) M(-1) for 4-chlorophenol.

Keywords: azo dye; chemosensor; chlorinated by-product; fluorescence; β-cyclodextrin polymer.

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Figures

Figure 1.
Figure 1.
Effect of pH on (A) azo dye modified β-CD and (B) azo dye modified β-CD polymer.
Figure 2.
Figure 2.
Fluorescence spectra of the azo dye CD polymer in different solvents. (λexc = 305 nm).
Figure 3.
Figure 3.
Fluorescence spectra of dye modified CD polymer on addition of different pollutants. {[Dye-CD-Polymer] = 50 ppm; [Pollutant] = 2.0 mM}.
Figure 4.
Figure 4.
Fluorescence quenching by addition of increasing amounts of 2,4-DCP. {[Dye-CD-Polymer] = 50 ppm; [2,4-DCP] = 0 mM to 2.7 mM}.
Figure 5.
Figure 5.
Plot of concentration of 2,4-DCP versus the change in fluorescence intensity (ΔI) with each addition of 2,4-DCP.
Figure 6.
Figure 6.
Benesi-Hildebrand plot of CD dye polymer in presence of 2,4-DCP (0–2.7 mM).
Scheme 1.
Scheme 1.
Structure of azo dye modified β-cyclodextrin.
Scheme 2.
Scheme 2.
Synthetic route to cyclodextrin polymer 4.
See this image and copyright information in PMC

References

    1. Thomas SW, Joly GD, Swager TM. Chemical sensors based on amplifying fluorescent conjugated polymers. Chem. Rev. 2007;107:1339–1386. - PubMed
    1. Basabe-Desmonts L, Reinhoudt DN, Crego-Calama M. Design of fluorescent materials for chemical sensing. Chem. Soc. Rev. 2007;36:993–1017. - PubMed
    1. Ogoshi T, Harada A. Chemical sensors based on cyclodextrin derivatives. Sensors. 2008;8:4961–4982. - PMC - PubMed
    1. Steed JW, Atwood JL. Supramolecular Chemistry. John Wiley & Sons, Inc; Hoboken, NJ, USA: 2000. pp. 2–5.
    1. Wang J, Ueno A. Naphthol-modified β-cyclodextrins as fluorescent sensors for detecting contaminants in drinking water. Macromol. Rapid Commun. 2000;21:887–890.

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