Carbon Nanoparticle

Sensors and Actuators B 162 (2012) 194–200

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Sensors and Actuators B: Chemical
journal homepage: www.elsevier.com/locate/snb

Carbon nanoparticle–chitosan composite electrode with anion, cation, and neutral binding sites: Dihydroxybenzene selectivity
Mandana Amiri a,∗ , Shahnaz Ghaffari b , Abolfazl Bezaatpour a , Frank Marken c
a b cDepartment of Chemistry, University of Mohaghegh Ardabili, Ardabil, Iran Department of Chemistry, Payame Noor University, Ardabil, Iran Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK

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A voltammetric study of dihydroxybenzene isomers has been carried out at the surface of a glassy carbon electrode modified with a carbonnanoparticle–chitosan high surface area composite film. Generally, the adsorption of analytes into the nanocomposite film is possible based on cation (chitosan), anion (surfacesulfonates of Emperor 2000TM particles), and neutral sites (graphitic carbon). Although all three types of adsorption are observed in aqueous media, the dominant effect is shown here to be weak adsorption of neutral moleculessuch as dihydroxybenzenes, which are bound and detected with good sensitivity and selectivity. Potential sweep rate and pH effects on the response of the electrode for the oxidation of dihydroxybenzens are investigated. At pH 7 separate oxidation peak potentials were observed at 0.10, 0.19, and 0.58 V versus SCE for hydroquinone, catechol, and resorcinol, respectively. Dynamic linear rangesobtained in differential pulse voltammetry analysis were 8.0 × 10−7 –1.0 × 10−4 , 8.0 × 10−7 –1.0 × 10−4 , and 8.0 × 10−6 –1.0 × 10−3 mol L−1 . The detection limits were 2.0 × 10−7 , 2.0 × 10−7 , and 3.0 × 10−6 mol L−1 . Real water samples were analyzed and recoveries from 96% to 108% were obtained. The new low cost method is proposed for application in the simultaneous determination of dihydroxybenzeneisomers for environmental analysis. © 2011 Elsevier B.V. All rights reserved.

Article history: Received 2 October 2011 Received in revised form 10 December 2011 Accepted 19 December 2011 Available online 8 January 2012 Keywords: Carbon nanoparticle Voltammetry Chitosan Adsorption Dihydroxybenzenes Wastewater

1. Introduction Phenolic compounds are important and often classified as “secondtype” of environment pollutions [1,2]. Hydroquinone (HQ), 1,4-dihydroxybenzene, catechol (CA), 1,2-dihydroxybenzene, and resorcinol (RS), 1,3-dihydroxybenzene, are three isomers of dihydroxybenzene that often coexist in environmental samples. They are usually employed as industrial reagents in the production of rubber, dyes, plastics, pharmaceuticals, and cosmetics [3,4]. Due to their similarstructures, it was important to develop a simultaneous and simple analytical procedure for dihydroxybenzene isomer detection in situ. Known methods for the simultaneous determination of dihydroxybenzene isomers are HPLC [5], capillary electro-chromatography [6], and spectrophotometry [7,8]. However, these techniques have some disadvantages, such as time consuming need for pre-separation, complicatedoperation, or a narrow linear range. Here a low cost modified-electrode methodology is proposed based on a carbon nanoparticle–chitosan active film.

∗ Corresponding author. Tel.: +98 451 5514701; fax: +98 451 5514703. E-mail address: mandanaamiri@yahoo.com (M. Amiri). 0925-4005/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.snb.2011.12.066

There are several directelectrochemical methods for dihydroxybenzene isomer determination, for example using poly-(acid chrome blue K)/carbon nanotube–composite electrodes [9], singlewall carbon nanotube electrodes [10], multi-electrode arrays modified with carbon nanotubes [11], poly-(p-aminobenzene sulfonic acid) modified glassy carbon [12], boron-doped diamond electrodes [13], and graphene–chitosan modified electrodes...