Lysozyme imprinted Fe3O4@SiO2 nanoparticles via SI-ATRP with temperature-controlled reversible adsorption

Nanoscale molecularly imprinted polymers (MIPs) could offer high binding capacity and fast mass transfer, but their removal after adsorption is costly and time-consuming. In this paper, Fe3O4@SiO2 nanoparticles were synthesized and a lysozyme-imprinted polymer was synthesized via surface initiated atom transfer polymerization on the surface of Fe3O4@SiO2. Temperature-controlled adsorption and desorption of lysozyme were measured, and the adsorption kinetics and isothermal adsorption were determined. The results indicate that the synthesized Fe3O4 has an inverse spinel crystalline structure and Fe3O4@SiO2 is a core–shell structured nanoparticle. The adsorption kinetics followed the Langmuir EXT1 model, and the equilibrium adsorption capacity of the Fe3O4@SiO2@MIP at 40 °C was 117.12 mg g−1 with an imprinting factor of 1.51. SDS-PAGE electrophoresis confirmed the specific adsorption of lysozyme, and 86% of the adsorbed lysozyme could be released by changing the temperature.