Mentha leaf extract-assisted Mn-doped bismuth oxide-modified electrode for electrochemical monitoring of sunset yellow

Metal oxide-based electrochemical sensors have gained significant attention in recent advancements due to their simplicity, cost-effectiveness, portability, and exceptional performance. Their sensitivity, repeatability, stability, and reproducibility make the sensor highly effective for the accurate detection of specific analytes in food safety applications. In this study, a mentha leaf extract-manganese-doped bismuth oxide (M-Mn-doped Bi₂O₃)-modified graphite electrode (GE)-based electrochemical sensor was developed as a sensitive sunset yellow (SY) sensor for food colorant detection. The hydrothermal method was employed to prepare M-Mn-doped Bi₂O₃ nanoparticles. The chemical bonding, crystal structure, elemental content, and morphology of M-Mn-doped Bi₂O₃ nanoparticles were validated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), and field emission scanning electron microscopy (FESEM), respectively. A sensing study using differential pulse voltammetry (DPV) revealed a linear relation between anodic peak current and SY concentrations from 1 to 5 µM. The maximum current response was achieved within the optimal potential range of − 500 mV to 600 mV at pH 10. The electrochemical sensor exhibited a strong linear relationship between SY concentration and current, with a detection limit (LOD) of 0.72 µM and a quantification limit (LOQ) of 2.41 µM. The correlation coefficient R² is 0.98, and the sensing probe sensitivity is 0.245 μA/μM/cm². The selectivity and real sample analysis were experimented. The real sample analysis for artificial colorants, soft drinks, and candies achieved the recovery percentage between 97.5 and 104%. As a result, the experimental investigation of the M-Mn-doped Bi₂O₃ nanoparticles sensor revealed that it is a promising material for detecting sunset yellow in food safety.