Poly(aminohippuric acid)-sodium dodecyl sulfate/functionalized graphene oxide nanocomposite for amplified electrochemical sensing of gallic acid

Gallic acid (GA), as a main phenolic acid, has been considered the main player on the human health, including the effects of reduction of cholesterol, depression of hypertension, anti-oxidation, anti-microbial, protection against cardiovascular disease and cancer. This study describes the development, electrochemical characterization and utilization of a novel functionalized graphene oxide/poly(p-aminohippuric acid)-sodium dodecyl sulfate nanocomposite modified glassy carbon electrode (APTS@GO/PPAH-SDS/GCE) for the electrocatalytic determination of GA. The synthesized nanocomposite was characterized by different techniques such as Fourier-transform infrared spectroscopy, thermo-gravimetric analysis and transmission electron microscopy. The electrochemical oxidation of GA was investigated by cyclic voltammetry, differential pulse voltammetry and amperometry. The modified electrode showed a potent and persistent electron mediating behavior followed by well-defined oxidation peak of GA and the linear range of 0.006-2000 A mu mol L-1 with a detection limit of 1.7 nmol L-1 for GA (S/N = 3) using amperometric method. Also, it was successfully used for the GA determination in the black tea and tab water as real samples. Additionally, this electrode exhibited good stability and reproducibility. The results imply that the APTS@GO/PPAH-SDS nanocomposite might be a promising candidate for practical applications in GA electrochemical detection.