Synthesis and Characterization of Self-Assembled Monolayer and Bilayer Carboxyl-Group Functionalized Magnetic Nanoparticles

Magnetic nanoparticles functionalized with carboxyl-group have considerable potential to be used as bio-labels due to their conjugation abilities with proteins. Here, we synthesized the iron oxide nanoparticles functionalized with carboxyl groups through self-assembled monolayer coating using citric acid and self-assembled bilayer coating using fatty acids. Their dimension, hydrodynamic size, surface property, and magnetic behavior were characterized through transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and vibrating sample magnetometry. We also confirmed the binding ability of these nanoparticles with bovine serum albumin on thin gold film.