Kinetic study and characterization of a platinum electrode/sensitive membrane for malachite green detection

Abstract

Purpose The purpose of this work is to explore electrical properties of an electrochemical sensor designed for the detection of malachite green (MG) present in an aqueous solution. Design/methodology/approach The present sensor consists in the spatial coupling of a polymeric membrane and an ion-sensitive electrode (platinum electrode). The preparation of the polymeric membrane involves the incorporation of an ionophore (D2HPA), a polymer (polyvinylchloride [PVC]) and a plasticizer (dioctyl phthalate [DOP]). Several techniques have been used to characterize this sensor: the cyclic voltammetry, the electrochemical impedance spectroscopy and the optical microscopy. The sensibility, the selectivity and the kinetic study of a modified platinum electrode have been evaluated by cyclic voltammetry. Findings The obtained results reveal the possibility of a linear relationship between the current of reduction peaks and MG concentration. A linear response was obtained in a wide-concentration range that stretches from 10−5 to 10−13 mol L−1, with a good correlation coefficient (0.976) and a good detection limit of 5.74 × 10−14 mol L−1 (a signal-to-noise ratio of 3). In addition, the voltammetric response of modified electrode can be enhanced by adding a layer of Nafion membrane. Under this optimal condition, a linear relationship was obtained, with a correlation coefficient of 0.986 and a detection limit of 1.92 × 10−18 mol L−1. Originality/value In the present research, a convenient, inexpensive and reproducible method for the detection of MG was developed. The developed sensor is capable of competing against the conventional techniques in terms of speed, stability and economy.

Development of new modified electrode based on β-cyclodextrin for methylene blue detection

“…The electrode modified after immersion in 50 mL of MB solution at 10 À5 mol L À1 shows a remarkable increase in the oxidation and reduction peaks. This means that the deposited membrane is sensitive to the presence of the target dye (Ghodbane et al, 2018;Mecheri et al, 2017).…”

“…The platinum electrode was cleaned with acetone for 10 min and with piranha solution (1/3 H 2 O 2 , 2/3 H 2 SO 4 ) for 1 min, after which it was washed with water and dried with air (Moss et al, 1975;Ghodbane et al, 2018;Lamari et al, 2016;Zougar et al, 2014).…”

“…The membrane composition was optimized by using the mixture of b-cyclodextrin (an ionophore), PVC (polymer) and DOP (plastizer) with the following proportions: 8, 33 and 67 mg, respectively, diluted in 0.7 mL of tetrahydrofuran (THF) after 5 m L of polymeric membrane was deposited on the platinum electrode surface (Ghodbane et al, 2018;Lamari et al, 2016;Zougar et al, 2014;Zougar et al, 2008). The b -cyclodextrin was chosen as the receptor because many previous studies have shown its ability to extract the MB present in aqueous solutions (Yudiarto et al, 2000;Pitha et al, 1986;Connors, 1997;Szejtli, 1998;Frömming and Szejtli, 1993;Nitschke et al,1990;Zhang et al,2000;Zhang et al, 2003).…”

“…From this figure, we can ascertain that the presence of Nafion layer improves the sensitivity of the developed sensor; the slope of calibration curve in the presence of one layer of Nafion membrane are greater than the slope obtained in the absence of Nafion layer. The improvement provided by the presence of Nafion can be attributed to the very strong acidity of the grouping sulfonate (due to the presence of the side grouping strongly electro-attractor perfluoroether), in the presence of the relatively flexible hanging chains (channels) and into the structure of the material which favors the diffusion of the cation such as MB 1 (Ghodbane et al, 2018;Zougar et al, 2011).…”

Development and characterization of enzymatic biosensor based on lipase from porcine pancreas for propylparaben detection

“…The platinum electrode was cleaned with acetone for 10 min and with piranha solution for 1 min and finally dried in ambient air (Lamari et al, 2016;Ghodbane et al, 2018;Djaalab et al, 2019).…”