Facile synthesis of Au supported on ionic liquid functionalized reduced graphene oxide for simultaneous determination of Sunset yellow and Tartrazine in drinks

A new facile in situ reduction approach for the preparation of an ionic liquid of 1-allyl-3-methylimidazolium chloride (AMIM-Cl) functionalized reduced graphene oxide supported Au nanoparticle (ILRGO-Au) composite was demonstrated in this work. With the assistance of AMIM-Cl, ILRGO were dispersed easily in aqueous solution and exhibited an improved conductivity. Meanwhile, the Au nanoparticles uniformly loaded on the surfaces of the ILRGO which can increase the specific surface area as well as accelerate electron transfer. These advantages made the ILRGO-Au composites were successfully employed in the fabrication of facile and sensitive electrochemical sensor applied to the simultaneous determination of Sunset yellow (SY) and Tartrazine (Tz) in drinks. In the presence of constant concentration of one of the components, the concentrations of SY or Tz gave linear response ranges equal to 4.0   ×   10 −9 to 1.0   ×   10 −6 for SY and 7.0   ×   10 −9 to 1.5   ×   10 −6   M for Tz with detection limits of 5.2   ×   10 −10 for SY and 8.3   ×   10 −10   M for Tz (S/N   =   3), respectively. The new sensor showed good reproducibility and repeatability toward simultaneous determination of SY and Tz, indicating its potentials in detection of other food colorants.