Temperature-controlled ethanolamine and Ag-nanoparticle dual-functionalization of graphene oxide for enhanced electrochemical nitrite determination

Abstract A highly sensitive and electrochemically active sensor has been fabricated by using an ethanolamine (AE) and Ag-nanoparticle (AgNP) dual-functionalized graphene oxide (fG) architecture (Ag-AEfG). The Ag-AEfG nanocomposites can be constructed via a one-pot hydrothermal method. The AgNPs were uniformly dispersed on the AEfG surface as seen from scanning and transmission electron microscopy. The silver-nanostructure morphology can be controlled via the reaction temperature. The electrochemical properties of the Ag-AEfG-based sensor were investigated by cyclic voltammetry and amperometric techniques. The experimental results indicate that AgNPs act as a catalytic core, AE can be regarded as a reducing agent and the dispersant, AEfG, is a conductive platform. The novel sensor exhibits a high sensitivity towards nitrite. The detection limits (S/N = 3) for nitrite in phosphate buffer solutions (PBS, pH = 7.4) is 0.023 μM and the linear response range varies from 0.05 to 3000 μM. The novel sensor exhibits a high sensitivity, stability and satisfactory reproducibility. Therefore, it was used to determine the concentration of nitrite in tap water in Nanjing. This study can help us to integrate nanosilver and AEfG for use in advanced electrochemical sensors.