Folic acid conjugation of magnetite nanoparticles using pulsed electrohydraulic discharges

Abstract

The sonochemical coprecipitation reaction with moderate ultrasound irradiation in low vacuum environment was used to obtain aqueous colloidal suspensions of iron oxide nanoparticles (IONPs). 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 has proved an inverse cubic spinel structure of magnetite with Folic Acid attachment to the magnetite surface (mean crystallite diameter in the samples D = 27~29 ? 2 nm by XRD and SAXS). It was found that the processing with electrohydraulic discharges increases the colloidal stability of the Folic acid-magnetite nanoparticle dispersions.

Synthesis and Characterization of Citric Acid-Modified Iron Oxide Nanoparticles Prepared with Electrohydraulic Discharge Treatment

“…As in our previous study with folic acid conjugated IONPs, HVPD (electrohydraulic discharge) was applied before capping with CA in an aqueous medium as a surface activation and homogenization technique [ 33 ]. To modify the surface of MNPs with a carboxyl group, an aqueous solution of CA was added directly using a peristaltic pump, at atmospheric pressure and room temperature.…”

“…The electrohydraulic processing was performed in the high current mode, as described in a previous work [ 33 ]. This mode allows low voltage and high current discharges inside the closed 300 mL volume reactor in a low vacuum environment (1 kPa).…”

“…In particular, surface modifications are required to avoid agglomeration, as bare nanoparticles have insufficient long-term stability. They require hydrophilic and biocompatible surface coverage before they may be used in medical applications [ 33 , 34 , 35 ]. Alternative methods for synthesis and stabilization involve more elaborate procedures, such as a novel approach using microfluidics [ 36 , 37 , 38 ].…”

“…A pulsed discharge can be advantageous as a pre-treatment stage before capping the CA, since the shock-wave effect on the suspension destroys the large agglomerates without significant destruction of the initial nanostructures. The efficiency of agglomerate dispersion by electrohydraulic discharge is higher than that of dispersion employing ultrasonication [ 33 , 53 ].…”

Stable aqueous dispersions of bare and double layer functionalized superparamagnetic iron oxide nanoparticles for biomedical applications

“…The average size distribution of the particle agglomerates in the synthesized samples obtained by SAXS measurements is shown below. Data processing and modeling from the SAXS curve were performed as in our previous work, in which we prepared magnetite nanoparticles coated with folic acid using pulsed electrohydraulic discharges, in an automated chemical reactor [25].…”