Discipline: Chemistry & Chemical Sciences
Subcategory: STEM Research
Yongfeng Zhao - Jackson State University
Co-Author(s): Pohlee Cheah, Department of Chemistry, Physics, and Atmospheric Science, Jackson State University, MS; Paul Brown, Department of Chemistry, Physics, and Atmospheric Science, Jackson State University, MS; Terriona Cowan, Department of Chemistry, Physics, and Atmospheric Science, Jackson State University, MS
Ultrasmall iron oxide nanoparticles (IONPs) have shown great potential in T1-weighted magnetic resonance imaging (MRI). Monodisperse ultrasmall IONPs are conventionally synthesized by thermal decomposition procedure in organic solvent and required surface modification to make the IONPs water soluble for biomedical application. However, surface modification is proved to be sophisticated, time consuming and low efficient. In this study, ultrasmall IONPs with different functional groups were successfully synthesized via one-pot synthesis. The IONPs are prepared by first thermal decomposition of iron acetylacetonate Fe(acac)3 precursor in diethylene glycol (DEG), followed by mixing the surface ligands at the end of the reaction. This facile synthesis method enabled coating of different surface materials such as polyethylene glycol with thiol end group (thiol-PEG), and polyacrylic acid (PAA) onto the IONPs. The size growth of IONPs can be well controlled as evidenced by transmission electron microscopy (TEM) studies. The high water stability of nanoparticles was correlated with the change of hydrodynamic size and zeta potential. While TEM results showed no significant change in the nanoparticles core size before and after surface modification, hydrodynamic size slightly increases due to the presence of ligands molecules on the surface. The attachment of surface ligands was studied by FTIR and TGA. FTIR results indicated the corresponding functional group for each surface ligands as a result of surface modification. In addition, we confirmed the surface functional groups by conjugating fluorescence dyes on to the surface. The magnetic resonance phantom study show that the resulted nanoparticles can be used for T1-weighted MRI imaging. The effect of surface ligands on the relaxivities of IONPs were also studied.
Funder Acknowledgement(s): This research is supported by the NSF (HRD-1700390 and OIA-1757220)
Faculty Advisor: None Listed,
NSF Affiliation: HBCU-UP