Simultaneous electrochemical detection of nitrite and hydrogen peroxide based on 3D Au-rGo/FTO obtained through a one-step synthesis

Abstract

In this paper, Au and reduced graphene oxide (rGO) were successively deposited on fluorine-doped SnO 2 transparent conductive glass (FTO, 1 × 2 cm) via a facile and one-step electrodeposition method to form a clean interface and construct a three-dimensional network structure for the simultaneous detection of nitrite and hydrogen peroxide (H 2 O 2 ). For nitrite detection, 3D Au-rGO/FTO displayed a sensitivity of 419 µA mM −1 cm −2 and a linear range from 0.0299 to 5.74 mM, while for the detection of H 2 O 2 , the sensitivity was 236 µA mM −1 cm −2 and a range from 0.179 to 10.5 mM. The combined results from scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction measurements (XRD) and electrochemical tests demonstrated that the properties of 3D Au-rGO/FTO were attributabled to the conductive network consisting of rGO and the good dispersion of Au nanoparticles (AuNPs) which can provide better electrochemical properties than other metal compounds, such as a larger electroactive surface area, more active sites, and a bigger catalytic rate constant.