Molecularly Imprinted Electrochemical Sensor Based on Reduced Graphene Oxide-Gold Nanoparticles-Poly(p-aminobenzoic Acid) Nanocomposites for the Determination of Sunset Yellow

Background: In this work, the reduced graphene oxide decorated with gold nanoparticles (Au/rGO) had been synthesized on glass carbon electrode (GCE) using a simple one-step electrochemical method. The molecularly imprinted poly(p-aminobenzoic acid) (PABA) film was prepared for the analysis of sunset yellow (SY) on Au/rGO/GCE by electropolymerization of p-aminobenzoic acid (pABA) and SY.Methods: Methods, such as scanning electron microscope (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to characterize the successful formation of imprinted films.Results: Under optimized experimental conditions, the Au/rGO/GCE based molecularly imprinted sensor (MIP/Au/rGO/GCE) exhibited excellent performance for SY, and a linear range was obtained from 0.002 μM to 8 μM with a detection limit of 0.5 nM. The responses of the imprinted sensor maintained higher than 93% of the initial values after 15 days of storage.Conclusion: The MIP/Au/rGO/GCE has been used for the sensitive and selective detection of SY in real food samples with acceptable recoveries, the combination of Au and rGO significantly improved the sensitivity of the proposed sensor due to the synergistic effect of gold nanoparticles and rGO. The resulting sensor also exhibited satisfactory reproducibility and stability, and the proposed platform could be further expected for the detection of other food additives and various electroactive species.