Synergistic peroxidase-like activity of CeO2-coated hollow Fe3O4 nanocomposites as an enzymatic mimic for low detection limit of glucose

Fe3O4@CeO2 yolk-shell nanocomposites (NCs) were synthesized by growing CeO2 onto Fe3O4 hollow nanoparticles (NPs) as an artificial peroxidase for the purpose of elevated activity. The resultant NCs exhibited strong magnetic response with narrow size distribution and high surface area. Owing to the individual peroxidase-like catalytic activity of CeO2 onto Fe3O4 nanoparticles (NPs), Fe3O4@CeO2 NCs was investigated to achieve synergistic catalytic activity. As a result, the as-prepared Fe3O4@CeO2 NCs exhibited impressive peroxidase-like catalysis activity for 3, 3', 5, 5'-tetramethylbenzidine (TMB). Moreover, comparing with natural enzymes, hollow Fe3O4 NPs and CeO2 NPs, the Fe3O4@CeO2 NCs displayed a lower Michaelis constant (Km) value or stronger affinity to H2O2 and TMB. A limit of detection of 8.5 mu mol/L, for H2O2 and 21 mu mol/L. for glucose was attained with acceptable stability and reproducibility. The activation mechanism was also studies using competitive radical tests and Electron spin resonance (ESR) analysis. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.