Folic acid conjugation of magnetite nanoparticles using pulsed electrohydraulic discharges

The sonochemical coprecipitation reaction with moderate ultrasound irradiation in a low vacuum environment was used to obtain aqueous colloidal suspensions of iron oxide nanoparticles (IONPs). The synthesized magnetite nanoparticles were conjugated directly by folic acid using electrohydraulic discharges as a processing technique before modification of the surface of the nanoparticles. Electrohydraulic discharges were applied in two operational modes with high and low power pulsed direct currents between the electrodes. The physical and chemical properties of the obtained samples were studied using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and small angle X-ray scattering (SAXS). The investigation proved an inverse cubic spinel structure of magnetite with folic acid attachment to the magnetite surface (mean crystallite diameter in the samples, D, ranges 25-31 nm by XRD and SAXS). It was found that the processing with electrohydraulic discharges increased the colloidal stability of the folic acid-magnetite nanoparticle dispersions.