关键词: 血红蛋白, 类酶传感器, 过氧化氢, 磁性印迹纳米粒子, 磁性电极

Abstract: In this work, the surface-imprinted technique was used to prepare magnetic hemoglobin (Hb) imprinted nanoparticles, using Fe₃O₄@SiO₂ NPs as the carrier, Hb as the template molecule, and tetraethyl orthosilicate (TEOS) as the imprinted polymer monomer. The nanoparticles had a core-shell structure, with magnetic Fe₃O₄ NPs as the core and Hb imprinted polymers as the shell. Therefore, Hb could be concentrated and fixed on the surface of the magnetic imprinted nanoparticles (MMIPs NPs). Furthermore, MMIPs NPs were immobilized with chitosan (CS) on the surface of a magnetic electrode to constitute Hb enzyme-like biosensor to catalyze the reduction of hydrogen peroxide (H₂O₂). Compared with magnetic non-imprinted polymer nanoparticles (MNIPs NPs), the MMIPs NPs biosensor enhanced the response by 14.3%. Notably, an introduction of a magnetic field made the biosensor more sensitive owing to the paramagnetism of MNIPs NPs, Hb and O₂ molecules. The reduction current of H₂O₂ on Hb/MMIPs NPs modified magnetic glassy carbon electrode increased by 60.0%. Under the optimum condition, the linear detection range of H₂O₂ was 25 ~ 200 μmol·L^-1 with the detection limit of 3 μmol·L^-1 (S/N = 3), which showed that Hb enzyme-like biosensor had a good catalytic performance for H₂O₂.

Key words: hemoglobin, enzyme-like biosensor, hydrogen peroxide, magnetic imprinted nanoparticles, magnetic electrode