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

Abstract

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.