Surfactant-intercalated smectite modified electrode: sensitive electrochemical detection of methyl orange dye

ABSTRACT

This work describes the use of organosmectite modified electrode to evaluate the electrochemical behaviour and to develop an electroanalytical procedure for the determination of methyl orange (MO) dye in natural water. Organosmectites were prepared by intercalation of hexadecyltrimethylammonium cations at various ratios into the interlayer of smectite. The synthesised organosmectites were characterised by various physicochemical techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. An amperometric sensor based on organosmectite as electrode modifier for MO sensing purposes was then evaluated by means of clay-film modified electrode using square wave voltammetry (SWV). The electrochemical procedure for MO analysis by stripping voltammetry involves two successive steps: accumulation of MO at open circuit conditions followed by a voltammetric detection in a same medium by the SWV technique. The peak current obtained (after 5 min preconcentration of 15 µmol L⁻¹ MO solution) on a glassy carbon electrode coated by a thin film of the modified clay was more than 2.5 times higher than that exhibited by the same substrate covered by a film of the pristine clay. Under optimised conditions, a linear calibration curve for MO was obtained in the concentration range from 0.1 to 1.6 µmol L⁻¹, leading to a detection limit of 4 × 10⁻⁸ mol L⁻¹ (signal-to-noise ratio equal to 3). The interfering effect of various inorganic and organic ions likely to influence the stripping determination of the MO was also examined. To further validate application of this sensor, the proposed method was successfully used to the determination of MO in natural water with satisfactory results.

KEYWORDS:

• Organosmectite
• methyl orange
• square wave voltammetry
• clay-film modified electrode

Acknowledgements

These results were obtained through the financial support from The Academy of Science for the Developing World (TWAS) and Council of Scientific and Industrial Research (CSIR) Grant FR number 3240275037 awarded to Dr. Tcheumi Hervé Leclerc as postdoctoral fellow. Dr. Tcheumi Hervé Leclerc also thanks University of Maroua for the financial support granted in 2017.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

These results were obtained through the financial support from The Academy of Science for the Developing World (TWAS) and Council of Scientific and Industrial Research (CSIR) Grant FR number [3240275037] awarded to Dr. Tcheumi Hervé Leclerc as postdoctoral fellow. Dr Tcheumi Hervé Leclerc also thanks University of Maroua for the financial support granted in 2017.