Investigation of the electrocatalytic function of Fe3O4 nanoparticles and the application as cefotaxime sodium sensor

By a simple drop coating method, Fe₃O₄ nanoparticles (FeNP) were modified on a glassy carbon electrode to fabricate an amperometric sensor for cefotaxime sodium (CS) detection. The microstructure and electrochemical behaviour of the sensor were investigated by scanning electron microscope and electrochemical impedance spectrum. The electrocatalytic ability of the sensor to CS reduction reaction in Britton-Robinson (B-R) buffer solution (pH 5.2) was investigated by cyclic voltammetry and differential pulse voltammetry. Results suggested that the proposed sensor exhibited an excellent electrocatalytic activity towards the reduction of CS with a well-defined reduction peak and an obvious decrease of overpotential. The catalytic currents of CS were linearly dependent on the concentrations of CS in the range from 0.15 to 25 μM, with the detection limit of 0.1 μM. The sensor exhibited good stability and reproducibility, and it was successfully applied to determine the CS concentrations in CS injection samples.