CTAB functionalized graphene oxide/multiwalled carbon nanotube composite modified electrode for the simultaneous determination of sunset yellow and tartrazine

We have developed hexadecyl trimethyl ammonium bromide (CTAB) functionalized graphene oxide (GO)/multiwalled carbon nanotubes (MWNTs) modified glassy carbon electrode (CTAB-GO/MWNT/GCE) as a novel system for the simultaneous determination of two synthetic food colorants, sunset yellow (SY) and tartrazine (TZ). Cyclic voltammetric (CV) studies indicate that SY and TZ undergo reversible and quasi-reversible redox processes on CTAB-GO/MWNT/GCE, respectively, with substantially lowered peak potentials, suggesting the extraordinary electrocatalytic effect of CTAB-GO/MWNT/GCE. Further study revealed that the electrode reactions of both SY and TZ are predominantly adsorption-controlled process on the CTAB-GO/MWNT/GCE. At the same time, the oxidation peak potentials of SY and TZ were effectively separated on CTAB-GO/MWNT/GCE, and their simultaneous determination was possible. Operational parameters, such as the accumulation time, solution pH, and scan rate, which affect the analytical performance of determination, were optimized. The CTAB-GO/MWNT/GCE behaved linearly to SY and TZ in the concentration range of 1 x 10(-7) to 2 x 10(-5) M and 3 x 10(-8) to 6 x 10(-7) M with a detection limit of 1 x 10(-8) M and 5 x 10(-9) M, respectively. The proposed method was successfully utilized for simultaneous determination of SY and TZ in real food samples.