Electrochemical detection of nitrite (NO2) with PEDOT:PSS modified gold/PPy-C/carbon nitride nanocomposites by electrochemical approach

Abstract

This study was performed to prepare gold-modified-PPy(polypyrrole)-C/C3N4 nanocomposites (NCs) by simple pyrolysis and ultra-sonication techniques. The prepared NC was coated onto glassy carbon electrode (GCE) to achieve a modified, active working electrode of nitrite (NO2) electrochemical sensor. The structural morphology, crystallographic study, and opto-electronic properties of NCs were evaluated applying Field-Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), High-Resolution Transmission Electron Microscopy (HRTEM), Brunauer-Emmett-Teller (BET), powder X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet–visible spectroscopy (UV–vis.) analysis. Besides this, the electrochemical characterization of NCs was assessed by cyclic voltammetry (CV) and displayed substantial outcome favorable to electron sensing substrates. The working electrode prepared by coating of Au@PPy-C/C3N4 NCs on GCE using conducting binder poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which exhibited linear electrochemical responses applying differential pulse voltammetry (DPV) to the detection of NO2 in a wider range of 1.5 ∼ 22.5 µM in 7.0 pH buffer defined as linear dynamic range (LDR). Additionally, the NO2 sensor showed good sensitivity (91.1899 µAµM-1cm−2) and low limit of detection (LOD; 1.11 ± 0.05 µM) which are appreciable. Other parameters, reproducibility and response time were investigated properly and also found as reliable. Furthermore, the assembled sensor based on Au@PPy-C/g-C3N4 NCs/GCE disclosed its consistent performances in analyzing of environmental samples. Thus, this study exposed a facile strategy to the development of efficient electrochemical sensor using organometallic nanocomposites.