Thin-Film Modified Electrodes with Reconstituted Cellulose-PDDAC Films for the Accumulation and Detection of Triclosan
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- 作者：Michael J. Bonné ; Karen J. Edler ; J. Grant Buchanan ; Daniel Wolverson ; Elefteria Psillakis ; Matthew Helton ; Wim Thielemans ; Frank Marken
- 刊名：Journal of Physical Chemistry C
- 出版年：2008
- 出版时间：February 21, 2008
- 年：2008
- 卷：112
- 期：7
- 页码：2660 - 2666
- 全文大小：236K
- 年卷期：v.112,no.7(February 21, 2008)
- ISSN：1932-7455
文摘
A strategy for the formation of thin reconstituted cellulose films (pure or modified)) with embedded receptorsor embedded ion-selective components is reported. Cellulose nanofibril ribbons from sisal of typically 3-5nm diameter and 250 nm length are reconstituted into thin films of typically 1.5-2.0 
m thickness (or intothicker free-standing films). Cellulose and cellulose nanocomposite films are obtained in a simple solventevaporation process. Poly-(diallyldimethylammonium chloride) or PDDAC is readily embedded into thecellulose film and imparts anion permselectivity to allow binding and transport of hydrophobic anions. Thenumber of binding sites is controlled by the amount of PDDAC present in the film. The electrochemicalproperties of the cellulose films are investigated first for the Fe(CN)63-/4- model redox system and then forthe accumulation and detection of triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether, a hydrophobicpolychlorinated phenol). Pure nanocellulose thin films essentially block the access to the electrode surfacefor anions such as Fe(CN)63- and Fe(CN)64-. In contrast, in the presence of cellulose-PDDAC films,accumulation and transport of both Fe(CN)63- and Fe(CN)64- in electrostatic binding sites occurs (Langmuirianbinding constants for both are about 1.2 × 104 mol-1 dm3 in aqueous 0.1 M KCl). Facile reduction/oxidationat the electrode surface is observed. Triclosan, a widely used antifungal and antibacterial polychlorinatedphenol is similarly accumulated into cationic binding sites (Langmuirian binding constant about 2.1 × 104mol-1 dm3 in aqueous 0.1 M phosphate buffer pH 9.5) and is shown to give well-defined oxidation responsesat glassy carbon electrodes. With a cellulose-PDDAC film electrode (80 wt % cellulose and 20 wt % PDDAC),the analytical range for triclosan in aqueous phosphate buffer at pH 9.5 is about 10-6-10-3 mol dm-3.
m thickness (or intothicker free-standing films). Cellulose and cellulose nanocomposite films are obtained in a simple solventevaporation process. Poly-(diallyldimethylammonium chloride) or PDDAC is readily embedded into thecellulose film and imparts anion permselectivity to allow binding and transport of hydrophobic anions. Thenumber of binding sites is controlled by the amount of PDDAC present in the film. The electrochemicalproperties of the cellulose films are investigated first for the Fe(CN)63-/4- model redox system and then forthe accumulation and detection of triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether, a hydrophobicpolychlorinated phenol). Pure nanocellulose thin films essentially block the access to the electrode surfacefor anions such as Fe(CN)63- and Fe(CN)64-. In contrast, in the presence of cellulose-PDDAC films,accumulation and transport of both Fe(CN)63- and Fe(CN)64- in electrostatic binding sites occurs (Langmuirianbinding constants for both are about 1.2 × 104 mol-1 dm3 in aqueous 0.1 M KCl). Facile reduction/oxidationat the electrode surface is observed. Triclosan, a widely used antifungal and antibacterial polychlorinatedphenol is similarly accumulated into cationic binding sites (Langmuirian binding constant about 2.1 × 104mol-1 dm3 in aqueous 0.1 M phosphate buffer pH 9.5) and is shown to give well-defined oxidation responsesat glassy carbon electrodes. With a cellulose-PDDAC film electrode (80 wt % cellulose and 20 wt % PDDAC),the analytical range for triclosan in aqueous phosphate buffer at pH 9.5 is about 10-6-10-3 mol dm-3.