Preparation of Boronic Acid-Functionalized Magnetic Nano-Particles by Polarity-regulating Molecular Self-assembly

Abstract

Boronic acid-functionalized magnetic nanoparticles were prepared and characterized in this investigation. At first, the single-layer oleic acid-coated Fe3O4 magnetic nanoparticles were prepared by the chemical coprecipitation method and then the nanoparticles were surface-modified by a layer of poly(4-vinylphenylboronic acid) by the polarity-regulating molecular self-assembly technique to obtain the boronic acid-functionalized magnetic nanoparticles (Fe3O4@OA@BA). The resulted nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The results show that the molecules of oleic acid can form the inner layer chemisorption on the surface of Fe3O4 and the double-layer coating structure on the outer layer. The poly(4-vinylphenylboronic acid) coated nanoparticles with content about 26% have an average size of 15 nm and the saturation magnetization of 43 emu/g. Finally, the adsorption effect of Fe3O4@OA@BA on bovine serum albumin (BSA) was studied. Under optimal adsorption conditions, the adsorption capacity on BSA is 135μg/mg, which embodies the superiority of molecular self-assembly to prepare functionalized nanoparticles.