Amperometric hydrazine sensor based on the use of a gold nanoparticle-modified nanocomposite consisting of porous polydopamine, multiwalled carbon nanotubes and reduced graphene oxide

A porous hybrid material was prepared from polydopamine-modified multiwalled carbon nanotubes and reduced graphene oxide. It was employed as a supporting material for an electrochemical hydrazine sensor. Gold nanoparticles with a size of about 13 nm were placed on the material which then was characterized by transmission electron microscopy, field emission-scanning electron microscopy, Raman spectra, FTIR and nitrogen absorption/desorption plots. The material is highly porous and has a specific surface of 290 m(2) g(-1), which is larger than that of P-MWCNT/rGO alone (149 m(2) g(-1)), and an increased pore volume. It was placed on a glassy carbon electrode (GCE), and cyclic voltammetry, chronoamperometry and amperometric i-t curves were used to characterize the catalytic activity of the sensor. The kinetic parameters of the modified GCE were calculated which proved that it has a high catalytic efficiency in promoting the electron transfer kinetics of hydrazine. The amperometric signal (obtained at a typical working potential of 0.35 V vs. SCE) has two linear ranges, one from 1 mu M - 3 mM and one from 3 to 55 mM, with sensitivities of 524 and 98 A mM(-1) cm(-2), respectively. The detection limit is 0.31 mu M. The porous nanocomposite was synthesized by etching silver nanoparticles and a enhanced non-enzymatic electrochemical sensor of hydrazine was successfully designed. The electrochemical performances of the modified electrode were also examined.