ZnFe₂O₄ Nanoparticles for Electrochemical Determination of Trace Hg(II), Pb(II), Cu(II), and Glucose

ZnFe2O4 (ZFO) spinel magnetic nanoparticles with a small particle size (11.2 nm) and large specific surface area (54.1 m2/g) are synthesized by a one-step hydrothermal method without the calcination process. ZFO-modified electrodes are first utilized for the simultaneous electrochemical trace detection of Hg(II), Pb(II), and Cu(II), which show an outstanding linear response for Hg(II), Pb(II), and Cu(II), and the limit of detection (LOD) is 1.61, 7.38, and 12.03 nM, respectively. Meanwhile, ZFO-modified electrodes exhibit excellent repeatability [relative standard deviation (RSD) of 0.785%], reproducibility (RSD of 0.896%), stability (RSD of 3.240%), and anti-interference analysis, which is successfully applied to the real water environment. Moreover, the ZFO-modified electrode also exhibits a high sensitivity of 1160 μA mM–1 cm–2 and LOD of 0.8 μM for glucose. These results indicate that ZFO nanoparticles as a promising modified electrode material will be potentially applied in the field of electrochemical sensors for heavy metal ions and nonenzymatic glucose.