A novel and efficient voltammetric sensor for the simultaneous determination of alizarin red S and tartrazine by using poly(leucine) functionalized carbon paste electrode

Abstract

In the current work, a rapid, selective, and sensitive technique was developed for the detection of Alizarin Red S (ARS) by applying poly leucine modified carbon paste electrode (PLMCPE). Electrochemical impedance spectroscopy (EIS) and Scanning electron microscopy (SEM) were utilized to study the surface morphology of unmodified carbon paste electrode (UMCPE) and PLMCPE. The active surface area for UMCPE and PLMCPE was found to be 0.0012 cm² and 0.0026 cm² respectively. The electrochemical response of ARS at UMCPE and PLMCPE was analyzed using cyclic voltammetry (CV) in the potential window of 0.4 to 1.0 V. The cyclic voltammogram obtained for varying the pH of 0.2 M phosphate buffer (PB) solution showed maximum current for the oxidation of ARS at pH 6.5. The electrochemical reaction of ARS was found to be irreversible and adsorption controlled. The effect of variation of concentration of ARS on the oxidation peak current was evaluated using CV and linear scan voltammetry (LSV). A linear relationship between the concentration variation and current was obtained in the linear range of 1.5 μM–3.5 μM and 0.2 μM–5.0 μM for CV and LSV respectively. The limit of detection (LOD) of 0.68 μM for the CV method and 0.29 μM for the LSV method was exhibited by the developed sensor. The simultaneous study of ARS along with tartrazine (TZ) showed good selectivity for ARS. The interferents of foreign molecules showed no effect on the selectivity of the electrode. The applicability of PLMCPE on real samples gave good recovery ranging from 97.46–101.2%; hence, the sensor can be utilized on real samples. The developed sensor has good stability and sensitivity.

Keywords:

• Alizarin red S
• leucine
• impedance study
• carbon paste electrode
• tartrazine

Acknowledgement

J.G. Manjunatha gratefully acknowledges the financial support from VGST, Bangalore under the Research project. No. K-FIST (L2)/GRD-1020/2021-22/430. Sameh M. Osman gratefully acknowledges the financial support from Researchers Supporting Project number (RSP2023R405), King Saud University, Riyadh, Saudi Arabia.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

Data will be made available on reasonable request.

Additional information

Funding

J.G. Manjunatha gratefully acknowledges the financial support from VGST, Bangalore under the Research project. No. K-FIST (L2)/GRD-1020/2021-22/430. Sameh M. Osman gratefully acknowledges the financial support from Researchers Supporting Project number (RSP2023R405), King Saud University, Riyadh, Saudi Arabia.