In this work, synthesis of bismuth ferrite (Bi₂₄Fe₂O₃₉) nanoparticles, fabrication of bismuth ferrite nanoparticle modified carbon paste electrode (CPE), characterization and electrochemical sensor application of bismuth ferrite nanoparticle modified CPE for electrochemical determination of lead and cadmium is reported. To the best of our knowledge, no work about such an electrode for electrochemical determination of lead and cadmium has been reported to date. The characterization of bismuth ferrite nanoparticles were studied by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The XRD result demonstrates the synthesized powder has a tetrahedral crystalline structure with particle size of 30.8 nm. For electroanalytical detection of Pb(II) and Cd(II); differential pulse stripping voltammetric (DPSV) signal were taken and a linearly dependent peak current versus concentration in the range of (2-200 μM) with regression coefficient (R²) of 0.9769 and 0.988 for Pb(II) and Cd(II) respectively was obtained. The method also showed low detection limit of 0.03 μM for Pb²⁺ and 0.06 μM for Cd²⁺. The analytical application of the developed method was tested on Pb(II) in tap water sample giving a recoveries in the range of the range of 96.2-102 % validating the applicability of the method.

Fig. 1 A typical XRD patterns of Bi₂₄Fe₂O₃₉ and DPSVs containing different equimolar mixture of Pb(II) and Cd(II) with calibration plot.