Enzymeless electrochemical determination of hydrogen peroxide at a heteropolyanion-based composite film electrode

Abstract

Constructing a specific nanocomposite film with a large surface area and excellent electrocatalytic activity is important for its application as an electrochemical sensor. In this study, for the first time, an ultrahigh performance composite film based on a heteropolyanion PW₉V₃O₄₀³⁻ (abbreviated as WV) decorated by Pt@Pd alloy nanoparticles (Pt@Pd NPs) and Prussian blue nanoparticles (PB NPs) was illustrated via a layer-by-layer self-assembly approach. The composition, morphologies, and nanostructures characteristics of the [PB/WV–Pt@Pd]₆ composite film were completely studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-vis spectroscopy, FT-IR spectra, and X-ray photoelectron spectroscopy (XPS), respectively. The special irregular morphology of the [PB/WV–Pt@Pd]₆ composite film provides a high specific surface area to boost the electrochemical activity, while the larger roughness and strong electronic cloud facilitate H₂O₂'s fast reduction at pretty low potential. Under optimum conditions, the [PB/WV–Pt@Pd]₆ composite film-based sensor presented a broad linear scope of 4.00 × 10⁻⁷ M to 2.65 × 10⁻³ M and a low detection limit of 1.00 × 10⁻⁷ M (S/N = 3). Thus, with seeming stability, anti-interference performance, and selectivity, the suggested sensor could be conceivably utilized to detect H₂O₂ in actual samples.