Immobilization of fluorescent protein TagGFP2 on Fe3O4-based magnetic nanoparticles

Abstract

The immobilization of fluorescent protein TagGFP2 on Fe₃O₄-based magnetic nano particles (MNPs), preliminarily functionalized with 3-aminopropylsilane and N-(phosphonomethyl) iminodiacetic acid (PMIDA), was studied. Protein binding to MNPs depending on the nature of the surface functional groups, the medium, and the presence of a coupling agent, namely, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC), was studied using fluorimetry, UV and IR spectroscopy. It was shown that protein immobilization can occur by both non-covalent and covalent binding with surface groups of MNPs. The best results (up to 150 μg of TagGFP2 per 1 mg of MNPs) were obtained for MNPs preliminarily functionalized with PMIDA and using EDC. The results of this study can be used for the design of imaging agents having both magnetic and optical properties to be applied in biomedicine.