Highly Sensitive Amperometric Sensor Based on Gold Nanoparticles Polyaniline Electrochemically Reduced Graphene Oxide Nanocomposite for Detection of Nitric Oxide

Authors

Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran

Abstract

A sensitive electrochemical sensor was fabricated for selective detection of nitric oxide (NO) based on electrochemically reduced graphene (ErGO)-polyaniline (PANI)-gold nanoparticles (AuNPs) nanocomposite. It was coated on a gold (Au) electrode through stepwise electrodeposition to form AuNPs-PANI-ErGO/Au electrode. The AuNPs-PANI-rGO nanocomposite was characterized by Field Emission Scanning Electron Microscopy (FESEM) and UV-vis. Electrochemical behavior of modified electrode was analyzed by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. CVs of AuNPs-PANI-ErGO/Au, PANI-ErGO/Au and ErGO/Au electrodes showed that conductivity of AuNPs-PANI-ErGO/Au was higher than others. Nafion was used to improve selectivity of modified electrode. Nafion/AuNPs-PANI-ErGO/Au electrode represented favorable electrochemical and electrocatalytic behavior towards NO oxidation. The resultant electrode exhibited a high sensitivity of 0.113 μA/μM over a wide linear range from 0.8 × 10−6 to 86 × 10−6 M with a low detection limit of 2.5 × 10−7 M (S/N=3). In addition,  the  sensor  had  excellent  stability,  as  well  as  reproducibility and  selectivity, which makes it possible to detect NO quickly and accurately.

Keywords