Reducing Non-Specific Adsorption of Proteins via the HPG Modification on the Surface of Magnetic Nanoparticles

Abstract

Reducing non-specific adsorption of proteins on the surface of magnetic nanoparticles (MNPs) is becoming increasingly important. In this paper, we proposed a novel surface modification procedure by grafting hyperbranched polyglycerol (HPG) onto the surface of MNPs (Fe3O4@SiO2@MAA), in which lots of hydroxyl groups from HPG not only provide the hydrates sheath to prevent non-specific adsorption of proteins, but also react with succinic anhydride to generate carboxyl groups that serve as active sites to specifically bind proteins. The protein adsorption experiments showed that the non-specific adsorption (0.07 μg mg-1) was reduced to 4.58% of that before modification. It also showed that the antigen binding capacity was 9.7 times higher than the original when detecting cardiac troponin I (cTnI) in human plasma samples, which indicated that the final synthesized MNPs had great application prospects in bio-separation and bioanalysis.