Optimization of oleylamine-Fe3O4/MWCNTs nanocomposite modified GC electrode for electrochemical determination of ofloxacin.

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.