Hydrophilic hybrid materials with magnetism & NIR fluorescence via surface-initiated RAFT polymerization.

Abstract

In the current work, one monomer (denoted as MHB) capable of emitting near infrared (NIR) fluorescence under UV light excitation is prepared and employed to perform (co)polymerization with a commercial hydrophilic and biocompatible monomer, poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), on the surface of silica coated iron oxide nanoparticles (NPs). PEGMA is used to either copolymerize or chain-extend MHB after polymerization to improve the hydrophilicity of the NPs which is essential for practical application in bio-related areas. The as-prepared NPs in different surface modification steps were investigated by Fourier transfer infrared (FT-IR), thermogravimetric analysis (TGA), transmission electron microscope (TEM) and UV-vis spectroscopic techniques. The crystal form of the NPs was checked by powder X-ray diffraction (XRD) and it showed that the magnetic core is made up of ferroferric oxide. The magnetic properties of the NPs were measured by vibrating-sample magnetometer (VSM) and all NPs exhibited superparamagnetism. The final NPs possessing magnetic and NIR fluorescent properties have potential applications in biological areas as dual-model imaging agents, and their application as contrast agents for magnetic resonance imaging (MRI) is investigated.