An electrochemical sensor based on multiferroic NdFeO₃ particles modified electrode for the detection of H₂O₂

The high dielectric constant and lower dielectric loss make NdFeO₃ materials ideal for potential use in many several applications. Specifically, NdFeO₃ is a promising candidate for electrochemical sensing applications owing to its high thermal stability, and non-toxicity. In this present study, multiferroic NdFeO₃ particles are synthesized using a solid-state reaction at a higher temperature. Structural studies confirm that NdFeO₃ crystallizes in an orthorhombic symmetry. Elemental color mapping of the NdFeO₃ sample reveals there is no impurity, and that the sample comprises Nd, Fe, and O elements. In addition, the Nyquist plot suggests the contribution of grain and grain boundary effect towards the resistive and capacitive characteristics of NdFeO₃. Magnetic measurements at room temperature indicated an antiferromagnetic nature of the sample with a weak ferromagnetic component arising due to the canted nature of Fe³⁺. The non-collinear magnetic structure of NdFeO₃ promotes the ferroelectric loop. Single-phase room temperature NdFeO₃ multiferroics were coated upon the glassy carbon electrode with the aim of sensing hydrogen peroxide (H₂O₂) using a three-electrode electrochemical setup. The cyclic voltammetry technique showed an increase in the peak current with an upsurge in the concentration of H₂O₂ between 1 mM and 10 mM. The limit of detection, the limit of quantification, and sensitivity was calculated to be 0.87 µM, 2.92 µM, and 52.6 µA mM⁻¹ cm⁻² respectively. The correlation coefficient R² was found to be 0.9792. The value of linearity with regression coefficient was calculated to be R² = 0.9922 from the effect of scan rate. NdFeO₃ showed an excellent selectivity towards H₂O₂ in the presence of H₂SO₄, KCl, HCl, and NaOH, and good sensitivity for monitoring H₂O₂ in a real milk sample. The sensitivity of modified Glassy carbon electrode (GCE) in milk was calculated to be 46.58 µA mM⁻¹ cm⁻².