title: Enhanced peroxidase activity and tumour tissue visualization by cobalt-doped magnetoferritin nanoparticles.
abstract: Magnetoferritin (M-HFn) is a biomimetic magnetic nanoparticle with a human heavy-chain ferritin (HFn) shell, trapping a magnetite (Fe3O4) core that has inherited peroxidase-like activity. In this study, cobalt-doped M-HFn nanoparticles (M-HFn-CoxFe3-xO4) with different amounts of cobalt were successfully synthesized. Experimental results indicate that the controlled doping of a certain amount of cobalt into the magnetite cores of M-HFn nanoparticles enhances its peroxidase-like catalytic activity and efficacy for visualizing tumour tissues. For example, compared with sample Co0 (without cobalt doping), the peroxidase-like activity of the cobalt-doped nanoparticle sample Co60 (with a cobalt doping molar percentage of ∼34.2%) increases 1.7 times, and has the maximal reaction velocity (Vmax) values. Moreover, after a one-step incubation with Co60 nanoparticles, and using the peroxidase substrate 3,3'-diaminobenzidine tetrahydrochloride (DAB) for colour development, the tumour tissues of breast, colorectal, stomach and pancreas tumours showed a deeper brown colour with clear boundaries between the healthy and tumourous cells. Therefore, this suggests that the cobalt-doped magnetoferritin nanoparticles enhance peroxidase activity and tumour tissue visualization.
authors.affiliation: Paleomagnetism and Geochronology Laboratory, Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China. France-China Bio-Mineralization and Nano-Structures Laboratory, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China.
authors.forename: Tongwei
authors.initials: T
authors.lastname: Zhang
authors.forename: Changqian
authors.initials: C
authors.lastname: Cao
authors.forename: Xu
authors.initials: X
authors.lastname: Tang
authors.forename: Yao
authors.initials: Y
authors.lastname: Cai
authors.forename: Caiyun
authors.initials: C
authors.lastname: Yang
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Pan