Electrochemically reduced graphene oxide-based electrochemical sensor for the sensitive determination of ferulic acid in A-sinensis and biological samples

An electrochemically reduced graphene oxide (ERGO) modified glassy carbon electrode (GCE) was used as a new voltammetric sensor for the determination of ferulic acid (FA). The morphology and microstructure of the modified electrodes were characterized by scanning electron microscopy (SEM) and Raman spectroscopy analysis, and the electrochemical effective surface areas of the modified electrodes were also calculated by chronocoulometry method. Sensing properties of the electrochemical sensor were investigated by means of cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that ERGO was electrodeposited on the surface of GCE by using potentiostatic method. The proposed electrode exhibited electrocatalytic activity to the redox of FA because of excellent electrochemical properties of ERGO. The transfer electron number (n), electrode reaction rate constant (k(s)) and electron-transfer coefficient (alpha) were calculated as 1.12, 1.24 s(-1,) and 0.40, respectively. Under the optimized conditions, the oxidation peak current was proportional to FA concentration at 8.49 x 10(-8) mol L-1 to 3.89 x 10(-5) mol L-1 with detection limit of 2.06 x 10(-8) mol L-1. This fabricated sensor also displayed acceptable reproducibility, long-term stability, and high selectivity with negligible interferences from common interfering species. The voltammetric sensor was successfully applied to detect FA in A. sinensis and biological samples with recovery values in the range of 99.91%-101.91%. (C) 2014 Elsevier B.V. All rights reserved.