Prussian Blue Modified Ferritin Nanoparticles as Peroxidase and Catalase Mimetics and their Application in Glucose Detection

Prussian blue nanoparticles (PBNPs) have been certified a kind of mimetic enzyme possesses the advantages of stability, high catalytic activity and low prices. Ferritins are natural nanoscale structures with unique three-dimensional structures and biological functions. In this context, we synthesized PBNPs on the surface of the iron oxide core of ferritin taking use of the ferric iron of the core, we also intended to retain the specificity of ferritin for some biological use. Our results show the resulting nanostructures (Prussian blue-ferritin nanoparticles, PB-Ft NPs) got very small size and relatively high catalytic activity , furthermore, PB-Ft NPs successfully combined the intrinsic enzyme mimetic activity of PBNPs and the specificity to tumor cells of ferritin. The peroxidase-like activity and catalase-like activity of PB-Ft NPs were studied. Peroxidase-like activity which fits well the Michaelis-Menten kinetics was found strongly depending on pH, temperature and the concentration of PB-Ft NPs. Then a sensitive method for glucose detection was developed using glucose oxidase (GOx) and PB-Ft NPs. PB-Ft NPs displayed catalase-like activity in PH higher than 5.0, the generated oxygen was measured by the dissolved oxygen electrode.Enzyme-linked immunosorbent assay (ELISA) shows PB-Ft NPs possess both specificity and peroxidase-like activity.