The synergistic effect between graphene oxide nanocolloids and silicon dioxide nanoparticles for gallic acid sensing

For the first time, the synergistic effect of graphene oxide nanocolloids (nano-GO) and silicon dioxide (silica) nanoparticles (SiO2-nanoparicles) has been used to modify a glassy carbon electrode (GCE) for the determination of gallic acid (GA). The modified electrode surface was characterised by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXA) and Fourier transform infrared spectroscopy (FTIR). The electrochemical behaviour of the modified electrode was then studied, using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), showing that the electrode was sensitive to GA in a concentration range of 6.25 × 10−6 to 1.0 × 10−3 mol L−1, with a correlation coefficient R2 of 0.9956 and a limit of detection of 2.09 × 10−6 mol L−1 (S/N = 3). The proposed method was successfully used for the determination of GA in red wine, white wine and orange juice, with recoveries of 102.3, 95.4 and 97.6%, respectively.