A sensitive and selective electrochemical sensor based on graphene quantum dots/gold nanoparticles nanocomposite modified electrode for the determination of luteolin in peanut hulls

A simple and sensitive electrochemical sensor based on graphene quantum dots (GQDs) and gold nanoparticles (GNPs) nanocomposite modified glassy carbon electrode (GQDs/GNPs/GCE) was developed for the determination of luteolin. The GQDs/GNPs/GCE was prepared by electrodeposition method, and characterized by scanning electron microscopy and electrochemical impedance spectroscopy. The GQDs/GNPs nanocomposite showed excellent synergistic electrochemical activity for the oxidation of luteolin. Compared to bare GCE, the GQDs/GNPs/GCE resulted in a 16-fold increase in the oxidation current of luteolin in phosphate buffer at pH 5.0. Using the differential pulse voltammetry method, the dependence of the oxidation current vs. concentration was found to be linear from 1 x 10(-8) to 1 x 10(-8)M with a regression coefficient of 0.997, and the detection limit of luteolin was 1.0 nM (S/N = 3). The recovery was between 98.8% and 101.4% in peanut hull samples. This strategy might enable more opportunities for the electrochemical determination of luteolin in practical applications.