Bifunctional polydopamine@Fe3O4 core–shell nanoparticles for electrochemical determination of lead(II) and cadmium(II)

• The bifunctional nanocomposites were synthesized.
• A modified magnetic glassy carbon electrode was fabricated.
• The electrode was used for the selective detection of Pb2+ and Cd2+ ions.
• The proposed sensor features a wider linear range and higher sensitivity.

The present paper has focused on the potential application of the bifunctional polydopamine@Fe3O4 core–shell nanoparticles for development of a simple, stable and highly selective electrochemical method for metal ions monitoring in real samples. The electrochemical method is based on electrochemical preconcentration/reduction of metal ions onto a polydopamine@Fe3O4 modified magnetic glassy carbon electrode at −1.1 V (versus SCE) in 0.1 M pH 5.0 acetate solution containing Pb2+ and Cd2+ during 160 s, followed by subsequent anodic stripping. The proposed method has been demonstrated highly selective and sensitive detection of Pb2+ and Cd2+, with the calculated detection limits of 1.4 × 10−11 M and 9.2 × 10−11 M. Under the optimized conditions, the square wave anodic stripping voltammetry response of the modified electrode to Pb2+ (or Cd2+) shows a linear concentration range of 5.0–600 nM (or 20–590 nM) with a correlation coefficient of 0.997 (or 0.994). Further, the proposed method has been performed to successfully detect Pb2+ and Cd2+ in aqueous effluent.

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