Voltammetric Determination of Rhodamine B Using a ZIF-67/Reduced Graphene Oxide Modified Electrode

In the present article, the synthesis of zeolite imidazolate framework-67/reduced graphene oxide (ZIF-67/rGO) and voltammetric determination of Rhodamine B (RhB) are demonstrated. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption/desorption isotherms. It was found that the ZIF-67/rGO composite consists of ZIF-67 nano-particles highly dispersed on the rGO matrix and possesses a high specific surface area. Because of the synergistic effect of good conductivity of rGO and high surface area of ZIF-67, the ZIF-67/rGO—modified glassy carbon electrode exhibits good electrochemical behavior toward Rhodamine B (RhB) oxidation. The use of this electrode to quantitate RhB with differential pulse voltammetric method was successful with a broad linear range, from 0.96 to 44.07 μg.L-1 of RhB and a low limit of detection of 1.79 μg.L-1. The procedure was able to be applied to quantitatively determine RhB content in several food samples with an exceptional recovery rate (98-103%). The quantitative results highly agreed with that provided by high-performance liquid chromatography, revealing that this material is promising in in situ monitoring of other illegal additives in food.