An electrochemiluminescence sensor based on Ru(bpy)₃²⁺@Au and GO@CdS for detection of tartrazine

An electrochemiluminescence (ECL) sensor was constructed based on Ru(bpy)₃²⁺@Au and GO@CdS for the detection of tartrazine (TTZ). In the presence of the co-reactant TPrA, Ru(bpy)₃²⁺ and CdS quantum dots (QDs) were used as dual luminophores to synergistically amplify the ECL signal of the sensor. Gold nanoparticles (Au NPs) enhanced the electron transport capability of the system and thereby amplified the ECL intensity. Graphene oxide (GO), as a carrier, has a special wrinkle-like structure that not only adsorbed a substantial amount of CdS QDs but also prevented their agglomeration. Additionally, a more sensitive detection method was established based on the quenching of the ECL signal, which occurred due to the interaction between Ru(bpy)₃²⁺ and TTZ. A low detection limit (1.3 × 10^-13 mol·L^-1, S/N = 3) was obtained for TTZ concentrations ranging from 4.0 × 10^-13 to 4.0 × 10^-8 mol·L^-1. Finally, actual measurement results from three beverage samples demonstrated that the prepared sensors possess excellent practical capabilities for TTZ detection.