Fabrication of a gold nanocage/graphene nanoscale platform for electrocatalytic detection of hydrazine

Abstract

In this study, we report a novel graphene decorated gold nanocage nanocomposite through thermal modification route as a hydrazine sensor. Gold nanocages were synthesized, using the galvanic replacement between silver nanocubes and aqueous gold solution. Graphene nanosheets were functionalized by reaction with N,N-dimethylformamide (DMF) at relatively high temperature to generate chemically modified graphene (CMG). Surface topography and thickness of CMG nanosheets were obtained by atomic force microscopy (AFM). Ultraviolet visible (UV–vis) spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), Fourier transformed infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) were used to characterize the physicochemical properties of gold nanocage/CMG nanocomposite. The electrochemical behaviour of sensor was investigated using cyclic voltammetry (CV), amperometry and electrochemical impedance spectroscopy (EIS). It was found that the gold nanocage/CMG modified glassy carbon electrode (GCE) exhibits low oxidation potential (0.17V) with two linear ranges from 6μM to 30μM and 30μM to 1.7mM for sensing hydrazine with detection limit of 0.5μM. The modified electrode exhibits good selectivity for hydrazine amperometric response in the presence of common ions and some biological interfering species and it can be easily prepared which makes it reproducible. Furthermore, the present sensor exhibits high level of stability for the determination of hydrazine.