研究了纳米颗粒的多酶活性,包括过氧化物酶和过氧化氢酶,以及在葡萄糖高灵敏检测中的应用.
Copyright© 2012 American Scienti c Publishers All rights reserved Printed in the United States of America
Journal of Nanoscience and Nanotechnology Vol. 12, 1–8, 2012
Prussian Blue Modi ed Ferritin as Peroxidase Mimetics and Its Applications in Biological DetectionWei Zhang1, Yu Zhang1 , Yanhua Chen1, Suyi Li2, Ning Gu1 , Sunling Hu1, Ying Sun1, Xue Chen1, and Quan Li1State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, P. R. China 2 Zhongda Hospital, Southeast University, Nanjing 210096, P. R. China Ferritins are natural nanoscale structures composed with 24 subunits endowed with similar threedimensional structures. The iron is stored in the form of ferrihydrite phosphate in the hollow spherical ferritin shells. Prussian blue nanoparticles (PBNPs) have been certi ed a kind of mimetic enzyme with the advantages of stability, high catalytic activity and low prices. In this context, we designed a strategy to synthesize PBNPs of small size using ferritin as template and meanwhile retain the biological properties of ferritin. Our results show the resulting nanostructures (Prussian blue modi ed 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 speci city of ferritin. Peroxidase-like activity which ts 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. The consequence of Enzyme-linked immunosorbent assay (ELISA) shows PB-Ft NPs possess both speci city and peroxidase-like activity, which suggests that PB-Ft NPs can be served as a useful reagent in some biological detections.1
RESEARCH ARTICLE
Keywords: Prussian Blue (PB), Ferritin, Peroxidase, ELISA, Glucose Detection.
1. INTRODUCTIONVarious nanoparticles have shown great promise in the eld of biomedical and biosensing applications.1–7 Among them, Prussian blue nanoparticles (PBNPs) have been increasingly noted in the eld of mimetic enzyme, it is usually considered as an“arti cial enzyme peroxidase” because of its high surface activity and selectivity towards the reduction of hydrogen peroxide and oxygen, and it has been extensively used in the construction of electrochemical biosensors.8–11 In our previous work, PB modi ed Fe2 O3 magnetic nanoparticles (PBMNPs) were synthesized and demonstrated to have very high peroxidase-like activity,9 due to the low redox potential and excellent electron transfer capability. And PBMNPsSPA (staphylococcal protein A) conjugates were further constructed for ELISA detection. Ferritin is the cell’s storage compartment for iron from plants and animals to bacteria and a
rchaea. It is a native nanoscale structure with speci c biological functions. A molecule of ferritin is usually composed of
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24 subunits that form a hollow spherical shell of 8 nm in inner diameter which encases a core of up to 4500 Fe (III) atoms.12–14 Structural features of ferritins from humans, horse, bullfrog and bacteria are all essentially the same architecture in spite of large variations in primary structure,15 so ferritin from other organisms may have the same functions as human ferritin. Many nanoparticles, such as gold cluster17 and platinum nanoparticles (PtNPs),21 have been synthesized using ferritins as nano-reactors through ferritin-loading approach16–21 and assembly-disassembly approach.22 23 It is well known that Prussian blue staining is always used to indicate the presence of iron in the tissues24–28 and the uptake of iron oxide nanoparticles in cells,29–34 since ferric iron can readily react with the ferrocyanide in acidic condition, resulting in the formation of a bright blue pigment namely Prussian blue. From this, herein we report a simple method to synthesize PBNPs of very small size taking use of the nature nanostructure of horse spleen ferritin (HoSF) as template, where the PBNPs was synthesized by the reaction of ferrocyanide with the ferric iron at the surface of the iron oxide cores and deposited on thedoi:10.1166/jnn.2012.6871
J. Nanosci. Nanotechnol. 2012, Vol. 12, No. xx
1533-4880/2012/12/001/008