Speaker
Description
Magnetic nanoparticles (MNPs) are a popular choice for biomedicine due to their intrinsic magnetic properties. To fully utilize their potential, surface modification is essential to ensure their hydrophilicity, biocompatibility, and stability in a physiological environment.
This study focuses on the preparation and characterization of MNPs modified with polyvinyl alcohol (PVA). The MNPs were synthesized using the coprecipitation method with ferrous and ferric salts in an alkaline medium, followed by their dispersion in two PVA solutions with different molecular weights ($M_w = 30 000$ g/mol and $90 000$ g/mol). The prepared samples, referred to as MNPs, PVA$30$-MF and PVA$90$-MF, were characterized by various techniques including electron microscopy (TEM), dynamic light scattering (DLS), and magnetic measurements (SQUID), to study the morphology, particle size distribution and magnetic properties. TEM images revealed the formation of nearly spherical nanoparticles in all the samples with sizes ranging from $8$ to $11$ nm. Magnetic measurements demonstrated ferromagnetic behavior with saturation magnetization (MS) up to $70$ emu/g for uncoated MNPs. Samples PVA$30$-MF and PVA$90$-MF exhibited superparamagnetic behavior. Field-cooled (FC) and Zero-field-cooled (ZFC) measurements of magnetization at an applied field of $100$ Oe resulted in blocking temperature $T_B=86$ and $122$ K for PVA$30$-MF and PVA$90$-MF samples, respectively. These results clearly indicate the presence of a PVA layer on the surface of all individual MNPs. Next, AC susceptibility measurements were performed to calculate average hydrodynamic particle sizes and the outcomes were in good agreement with the results from DLS.
Finally, the catalytic activity of the prepared samples, simulating the function of natural biological enzymes was investigated. The findings indicate that both samples exhibit high catalytic activity resulting in their potential application in biosensing, detection of tumor cells and other biomedical applications.
Acknowledgements
This work was supported by the Slovak Research and Development Agency under the contract no. APVV-DS-FR-22-0037 and Slovak Grant Agency VEGA 02/0049/23.
References
[1] S. Ghosh and A. Jaiswal, “Peroxidase-Like Activity of Metal Nanoparticles for Biomedical Applications,” Nanobiomaterial Engineering. Springer Singapore, pp. 109–126, 2020. https://doi.org/10.1007/978-981-32-9840-8_6
