A Novel Electrochemical Sensor Based on Graphene Oxide Decorated with Silver Nanoparticles-Molecular Imprinted Polymers for Determination of Sunset Yellow in Soft Drinks

In this study, a new imprinted electrochemical sensor for selectively detecting sunset yellow was developed based on glassy carbon electrode (GCE) modified by graphene oxide decorated with silver nanoparticles-molecular imprinted polymers (GO/AgNPs-MIPs). GO/AgNPs were firstly synthesized using self-assembly technology, and GO/AgNPs-MIPs were synthesized through surface imprinted technology by using GO/AgNPs as the substrate and sunset yellow as the template, respectively. The sensor was prepared by a drop-casting method. The synthetic materials were characterized by transmission electron microscope (TEM), Fourier transmission infrared spectra (FT-IR), and X-ray diffraction (XRD). The sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The usage amount of GO/AgNPs-MIPs suspensions, solution pH, and accumulation time made an important difference in the process of detecting sunset yellow. Under optimal conditions, the peak current is linear to concentration of sunset yellow in the ranges of 0.1-0.6 and 0.6-12 mu M, and the limit of detection was estimated to be 0.02 mu M (S/N = 3). Finally, the proposed sensor was applied to detect sunset yellow in soft drinks with acceptable recovery, which demonstrated that the sensor could be used as a reliable and simple method for practical detection of sunset yellow.