Direct evidence for catalase and peroxidase activities of ferritin-platinum nanoparticles.
Using apoferritin (apoFt) as a nucleation substrate, we have successfully synthesized 1-2 nm platinum nanoparticles (Pt-Ft) which are highly stable. By directly measuring the products of Pt-Ft-catalyzed reactions, we showed, with no doubt, Pt-Ft possesses both catalase and peroxidase activities. With hydrogen peroxide as substrate, we observed oxygen gas bubbles were generated from hydrogen peroxide decomposed by Pt-Ft; the generation of oxygen gas strongly supports Pt-Ft reacts as catalase, other than peroxidase. While with organic dyes and hydrogen peroxide as substrates, distinctive color products were formed catalyzed by Pt-Ft, which indicates a peroxidase-like activity. Interestingly, these biomimetic properties showed differential response to pH and temperature for different reaction substrates. Pt-Ft showed a significant increase in catalase activity with increasing pH and temperature. The HRP-like activity of Pt-Ft was optimal at physiological temperature and slightly acidic conditions. Our current study demonstrates that Pt-Ft possesses both catalase and peroxidase activities for different substrates under different conditions.
CAS Key Laboratory for Biological Effects of Nanomaterials & Nanosafety, National Centre for Nanoscience and Technology, 11 Beiyitiao, ZhongGuanCun, Beijing 100190, China.
Jia
J
Fan
Jun-Jie
JJ
Yin
Bo
B
Ning
Xiaochun
X
Wu
Ye
Y
Hu
Mauro
M
Ferrari
Gregory J
GJ
Anderson
Jingyan
J
Wei
Yuliang
Y
Zhao
Guangjun
G
Nie
D002374:Catalase / Q000378:metabolism*; D002384:Catalysis; D005293:Ferritins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D009195:Peroxidase / Q000378:metabolism*; D010984:Platinum / Q000737:chemistry*; D013696:Temperature
D010984:Platinum; D005293:Ferritins; D006861:Hydrogen Peroxide; D002374:Catalase; D009195:Peroxidase