Efficient Amperometric Detection of H₂O₂ using Gold Nanoparticle decorated Polythiophene/Hematite Ore Nanocomposite

Abstract

In the present work, we developed a cheap and sensitive H 2 O 2 electrochemical sensor. Herein we fabricated an electrochemical sensor electrode using a naturally extracted hematite ore decorated with conducting polythiophene (Pth) and gold nanoparticles (AuNPs). A simple synthesis route was adopted for the electrocatalyst synthesis, where Pth was synthesized through oxidative polymerization and then combined with Hematite Ore nanostructure via a simple ultrasonication process. Later a simple photo-reduction approach was used to develop a 1%Au@5%Pth/Hematite Ore nanocomposite. The as-fabricated Au@Pth/Hematite Ore nanocomposite was successfully characterized by applying X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), High-Resolution Transmission Electron Microscope (HR-TEM), and Field Emission Scanning Electron Microscope (FE-SEM) techniques. The obtained results reveal that undoped naturally extracted hematite ore is composed of Fe 2 O 3 and Fe 3 O 4 phases. The catalytic efficiency of the newly designed nanocomposite and its sensing ability towards H 2 O 2 were assessed using electrochemical techniques including electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and highly sensitive amperometric (i-t) techniques. The Au@Pth/Hematite Ore/GCE sensor showed a wide linear dynamic range of 0.50–9.50 mM with high sensitivity of 69.18 μ AmM −1 cm −2 . The limit of detection (LOD) was estimated to be 5.18 μ M. The examined sensor demonstrated acceptable reproducibility, repeatability as well as stability. The sensor electrode also showed anti-interference behavior in the presence of different inorganic and organic interfering ions or molecules during the H 2 O 2 determination. Moreover, the proposed sensor exhibits acceptable recovery of H 2 O 2 in real sample analysis. Hence, this novel sensor is regarded as a promising contender in scientific and industrial domains.