Article

Fabrication of ZnSe nanoparticles in the apoferritin cavity by designing a slow chemical reaction system.

CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, Japan.
Inorganic Chemistry (impact factor: 4.6). 10/2005; 44(18):6393-400. DOI:10.1021/ic0502426 pp.6393-400
Source: PubMed

ABSTRACT Zinc selenide nanoparticles (ZnSe NPs) were synthesized in the cavity of the cage-shaped protein apoferritin by designing a slow chemical reaction system, which employs tetraaminezinc ion and selenourea. The chemical synthesis of ZnSe NPs was realized in a spatially selective manner from an aqueous solution, and ZnSe cores were formed in almost all apoferritin cavities with little bulk precipitation. Three factors are found to be important for ZnSe NP synthesis in the apoferritin cavity: (1) the threefold channel, which selectively introduces zinc ion into the apoferritin cavity, (2) the apoferritin internal potential, which favors zinc ion accumulation in the cavity, and (3) the nucleation site, which nucleates ZnSe inside the cavity. The characterization of the synthesized ZnSe NPs by X-ray powder diffraction and energy-dispersive spectrometry revealed that the synthesized NPs are a collection of cubic ZnSe polycrystals. It was shown that the 500 degrees C heat treatment for 1 h under nitrogen gas transformed the polycrystalline ZnSe core into a single crystal, and single-crystal ZnSe NPs free of protein were obtained.

0 0
 · 
0 Bookmarks
 · 
19 Views
  • Source
    Article: Temperature-modulated adsorption of poly(N-isopropylacrylamide)-grafted ferritin on solid substrate.
    Yoshikazu Kumashiro, Yasuhiro Ikezoe, Tomohiro Hayashi, Youichi Okabayashi, Kaoru Tamada, Masayuki Yamato, Teruo Okano, Masahiko Hara
    [show abstract] [hide abstract]
    ABSTRACT: Ferritin grafted with temperature-responsive poly(N-isopropylacrylamide) (PIPAAm-ferritin) was synthesized by a coupling reaction using PIPAAm and ferritin for obtaining stimuli-responsive biomaterials. The hydrodynamic diameter of PIPAAm-ferritins in aqueous solution increased at 37 °C at a higher protein concentration (>0.2mg/mL) because of the intermolecular aggregation through the hydrophobic interaction of PIPAAm chains. On the other hand, PIPAAm-ferritins at a lower concentration (<0.2mg/mL) were unable to increase their size even at 37 °C. The adsorption kinetics of PIPAAm-ferritins on hydrophobically modified Si substrate were evaluated with a quartz crystal microbalance in 10 mmol/L Bis-Tris/HCl buffer (pH 5.8) with and without poly(oxyethylene) sorbitan monolaurate (TWEEN 20) (0.05 wt%) as a surfactant. Although the adsorption of PIPAAm-ferritins on hydrophobic Si substrate at 25 °C in the buffer with TWEEN 20 was hardly observed, PIPAAm-ferritins were considerably adsorbed on the substrate at 37 °C, indicating that the hydrophobic interaction between the substrate and PIPAAm grafts on the ferritins after the destruction of the hydrophobic interaction between the protein and the substrate by TWEEN 20.
    Colloids and surfaces. B, Biointerfaces 02/2012; 95:57-64. · 2.60 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

500 degrees C heat treatment
 
apoferritin internal potential
 
cage-shaped protein apoferritin
 
cubic ZnSe polycrystals
 
employs tetraaminezinc ion
 
favors zinc ion accumulation
 
nitrogen gas
 
nucleates ZnSe
 
nucleation site
 
polycrystalline ZnSe core
 
selectively introduces zinc ion
 
single-crystal ZnSe NPs free
 
slow chemical reaction system
 
synthesized NPs
 
synthesized ZnSe NPs
 
X-ray powder diffraction
 
Zinc selenide nanoparticles
 
ZnSe cores
 
ZnSe NP synthesis
 
ZnSe NPs
 

Kenji Iwahori