Immobilized triton X-100 voltammetric sensor for the simultaneous detection of sunset yellow and tartrazine

In this study, we developed a sensor utilizing a pencil graphite electrode combined with triton X-100 surfactant prepared by immobilization technique. This modified electrode can concurrently detect sunset yellow (SY) and tartrazine (TZ) in a binary mixture. Both com¬pounds are synthetic azo dyes known to have hazardous effects on human health, including the potential for malignant growth at prolonged exposure. The modified electrode shows remarkable sensitivity toward SY and TZ individually and in combination. We conducted pH studies, scan rate analysis, reproducibility tests, and simultaneous detection studies using cyclic voltammetry. Differential pulse voltammetry technique was used to investigate concentration and mutual interference effects. Our pH study found that the maximum anodic peak current for SY occurs at pH 7.4, while TZ shows a higher current at pH 7.0. The scan rate analysis indicated that anodic reactions of both dyes are adsorption process controlled. The limit of detection (LOD) and limit of quantification (LOQ) for SY are 0.17 and 0.59 µM, respectively, while for TZ, the LOD and LOQ are 0.67 and 2.26 µM, respectively. The surfactant-modified pencil electrode demonstrates excellent peak separation between SY and TZ in a binary mixture, exhibiting stability of 86.3 % for sunset yellow and 65 % for tartrazine over 25 cycles.