Iron oxide (Fe3O4) nanoparticles are prepared by nucleation method using oleylamine (OLA) as the capping agent. The OLA capped Fe3O4 nanoparticles (OLA-Fe3O4) are characterized by Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD) and High Resolution Transmission Electron Microscopic (HRTEM) analysis. The morphology of the OLA-Fe3O4 nanoparticles is found to be spherical with an average size of 7.5 +/- 0.5 nm. OLA-Fe3O4 nanoparticles are incorporated into the carboxyl functionalized Multi-walled carbon nanotubes (MWCNTs) at different 10, 20, 30, 40 and 50 wt% by ultrasonication. The optimum loading of OLA-Fe3O4 nanoparticles on the MWCNTs was characterized by FTIR, Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and Linear Sweep Voltammetry (LSV). Finally, the 40wt% of OLA-Fe3O4 nanoparticles on MWCNTs was chosen as the optimum loading and this composition was used for the electrochemical oxidation of ofloxacin (OFX). For determination of OFX in OLA-Fe3O4/MWCNTs modified glassy carbon (GC) electrode show high sensitivity and fast response. The sensitivity of the modified electrode was calculated to be 0.578 microAmicroM(-1) with a detection limit of 0.060 microM. The high sensitivity, wider linear range, good reproducibility and the minimal surface fouling make this OLA-Fe3O4/MWCNTs/GC modified electrode acts as a promising platform for electrochemical determination of OFX.
