A novel voltammetric sensor based on poly(hydroxynaphthol blue)/ multi-walled carbon nanotubes modified glassy carbon electrode for the simultaneous determination of dihydroxybenzene isomers

Environmental monitoring has become one of the very important area of research. Increasing the industrial activities, different types of pollutants enter into the nature. Phenols and their derivatives are important compounds in industrial and agricultural production [1]. Dihydroxybenzene isomers are type of phenol derivatives. Catechol (CC), hydroquinone (HQ) and resorcinol (RS) are three dihydroxybenzene isomers. Because of the high toxicity and low degradability of these compounds in the environment, they are considered as environmental pollutants[2]. In order to protect the environment and human health, the development of rapid, accurate, sensitive and selective determination methods for monitoring these pollutants is essential. A novel voltammetric sensor was developed for simultaneous determination of dihydroxybenzene isomers based on a Poly(hydroxynaphthol blue)/ multi-walled carbon nanotubes modified glassy carbon electrode. The preparation and basic electrochemical performance of the novel sensor film modified glassy carbon electrode were investigated in details. The electrochemical behaviors of dihydroxybenzene isomers at the modified electrode were studied by cyclic and differential pulse voltammetric. The results showed that this new electrochemical sensor exhibited excellent electrocatalytic activity towards the oxidation of the three isomers. The mechanism of electrocatalytic was discussed. The modified electrode was used as a voltammetric sensor for sensitive simultaneous determination of dihydroxybenzene. Under the optimum conditions, the detection limits were 0.24, 0.24 and 0.26 µmol L−1 for hydroquinone, catechol and resorcinol, respectively. The proposed sensor has been successfully used in analysis of water samples.