Electrochemical Detection of Nitrite in Food Based on Poly (3,4-ethylenedioxythiophene) Doped with Fe3O4 Nanoparticles Loaded Carboxylated Nanocrystalline Cellulose

Carboxylated nanocrystalline cellulose (CNCC) was prepared by oxidation degradation of microcrystalline cellulose (MCC) using ammonium peroxydisulfate and modified with Fe3O4 nanoparticles to form Fe3O4-CNCC nanocomposite via simple refluxing process. The Fe3O4-CNCC nanocomposite doped poly(3,4-ethylenedioxythiophene) (PEDOT) was successfully decorated on the glassy carbon electrode (GCE) by electrochemical deposition. The PEDOT/Fe3O4-CNCC modified GCE with enlarged real electrochemical surface area was used to determine nitrite with high selectivity, sensitivity and outstanding reproducibility. Using amperometric current-time (i-t) curve, the proposed sensor provided a wider linear range (0.5–2500 μM) and a lower detection limit (0.1 μM) towards nitrite compared with the method of differential pulse voltammetry (DPV). This analytical method gave good selectivity in the practical measurement of nitrite in pickles.