A Sensor for Detection of 4-nitrophenol Based on a Glassy Carbon Electrode Modified with a Reduced Graphene Oxide/Fe3O4 Nanoparticle Composite

A simple sensor, based on a glassy carbon electrode (GCE) modified with a reduced graphene oxide (RGO) and Fe3O4 nanoparticle composites (Fe(3)O(4)NPs), was developed for detection of 4-nitrophenol (4-NP). The surface morphology of the prepared reduced graphene oxide/Fe3O4 nanoparticle composites was characterized by scanning electron microscopy (SEM). The RGO/Fe(3)O(4)NPs modified GCE was confirmed by cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of the as-obtained RGO/Fe(3)O(4)NPs toward 4-NP were investigated with differential pulse voltammetry (DPV) and square wave voltammetry (SWV). Under the optimal experimental conditions, the linear relationship between the peak current and the concentration of 4-NP was obtained from DPV in the range from 0.2 to 10 mu M, 20 to 100 mu M and SWV in the range from 0.2 to 10 mu M. And respectively, the limit of detection (LOD) of 4-NP was 0.26 mu M and 0.86 mu M for DPV and SWV. The sensor was used to determine the level of 4-NP in tap water samples with good recovery, highlighting the sensor's feasibility for industrial applications. The proposed sensor provided an efficient performances and acceptable stability for the detection of 4-NP in the water.