Preparation and characterization of bio-functionalized iron oxide nanoparticles for biomedical application

Abstract

Amine modified iron oxide (Fe 3O 4) nanoparticles were synthesized by thermal decomposition method and were further used to bio-functionalize by grafting of N-hydroxysuccinimide (NHS) ester of folate and ethylenediaminetetraacetate (EDTA). Fe 3O 4 nanoparticles of ~ 22 nm were confirmed from X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. FT-IR studies indicated two bands at 1515 cm − 1 and 1646 cm − 1 , which can be attributed to carboxylic group and the amide linkage respectively, revealing the conjugation of folate with Fe 3O 4. The conjugation of the chelating agent showed strong C=O stretch and Fe–O vibrations at 1647 and 588 cm − 1 respectively. The value of saturation magnetization for Fe 3O 4 nanoparticles was found to be 88 emu/g, which further reduced to 18 and 32% upon functionalization with EDTA and NHS ester folate, respectively. These amine modified Fe 3O 4 nanoparticles can also be functionalized with other bifunctional chelators, such as amino acids based diethylene triamine pentaacetic acid (DTPA), and thus find potential applications in radio-labeling, biosensors and cancer detection, etc.