The Sensitive and Selective Enzyme-Free Electrochemical H₂O₂ Sensor Based on rGO/MnFe₂O₄ Nanocomposite

The reduced graphene oxide/manganese ferrite (rGO/MnFe₂O₄) composite was prepared via a simple and straight forward solvothermal technique. The well-defined and mono-dispersed MnFe₂O₄ spherical particles with the average particle size of 370 nm, composing of 10-nm-sized primary nanoparticles were densely anchored over MnFe₂O₄ composite cons support. The cubic spinel structure of MnFe₂O₄ nanoparticles was unfurled through the diffraction patterns, and its compilation with rGO to form composite has sustained the structure, morphology, and size of MnFe₂O₄. The as-prepared rGO/MnFe₂O₄ composite exhibited superior electrocatalytic activity toward the enzyme-free H₂O₂ detection under neutral conditions. The as-fabricated rGO/MnFe₂O₄/glassy carbon electrode (GCE) exhibited an excellent enzyme-free H₂O₂ detection with a wide linear range of 1 μM–22 mM, a lower limit of detection of 0.35 μm (S/N = 3), and a considerable sensitivity of 1180 μA mM⁻¹ cm⁻². Furthermore, rGO/MnFe₂O₄/GCE demonstrated the high selectivity toward H₂O₂ without the influence of other electroactive species and exhibited the prompt recovery in the range of 97.84–102.23% toward real sample analysis, which ensured the viable applications of rGO/MnFe₂O₄ composite in electrochemical enzyme-free H₂O₂ sensors. [Figure not available: see fulltext.].