Efficient purification of lysozyme from egg white by 2-mercapto-5-benzimidazolesulfonic acid modified Fe3O4/Au nanoparticles

Abstract 2-Mercapto-5-benzimidazolesulfonic acid (MBISA) modified Fe 3 O 4 /Au nanoparticles were synthesized in aqueous solution and characterized by photo correlation spectroscopy (PCS) and vibrating sample magnetometer (VSM). The so-obtained Fe 3 O 4 /Au-MBISA nanoparticles were capable of specific adsorbing lysozyme. The maximum amount of lysozyme adsorbed on 1.0 mg Fe 3 O 4 /Au-MBISA nanoparticles was 346 μg. The lysozyme desorption behavior was studied and the lysozyme recovery from Fe 3 O 4 /Au-MBISA nanoparticles approached 100% under optimal conditions, and the reusability studies showed that the nanoparticles could maintain about 91% of the initial lysozyme adsorption capacity after 7 repeated adsorption–elution cycles. The Fe 3 O 4 /Au-MBISA nanoparticles were used in the purification of lysozyme from chicken egg white, which was verified by a single SDS-PAGE band. Therefore, the obtained Fe 3 O 4 /Au-MBISA nanoparticles exhibited excellent performance in the direct purification of lysozyme from egg white.