Preparation and electrochemical sensor application of tetra aniline/graphene oxide/gold nanoparticle composites`

Abstract

In this study, we have prepared a novel carbon nanocomposite paste electrode modified with tetra aniline/graphene oxide/gold nanoparticle (tetra aniline (TA)/GO/AuNP) composites. The electrode was applied for the electrochemical sensing of ascorbic acid (AA). TA was synthesized using the oxidation coupling method from n-phenyl-p-phenylenediamine, and its structure was characterized using liquid chromatography–mass spectrometry and Fourier transform infrared spectroscopy. TA/graphene oxide (GO) composites were prepared using their unique π-π interaction. Furthermore, AuNPs were captured with an amino group on the TA/GO composites to form ternary composites. The topography of the ternary composites was confirmed via scanning electron microscopy–energy dispersive spectroscopy and transmission electron microscopy. To observe the sensing properties of the composites, several electrochemical analyses were used. In cyclic voltammetry studies, TA/GO/AuNP composites exhibited a higher current response than the TA/GO nanocomposite. This result showed that ternary composites might accelerate the direct electron transfer between AA and the electrode. The detection sensitivities of the TA/GO- and TA/GO/AuNP-modified carbon paste electrodes (CPEs) were 8.73 and 19.30 μA·mM−1, respectively; there is a significant increase with the addition of AuNPs. These results confirm that the addition of nanometer-scale components affects the electrocatalytic activity.