Simple synthesis of functionalized superparamagnetic magnetite/silica core/shell nanoparticles and their application as magnetically separable high-performance biocatalysts.
Uniformly sized silica-coated magnetic nanoparticles (magnetite@silica) are synthesized in a simple one-pot process using reverse micelles as nanoreactors. The core diameter of the magnetic nanoparticles is easily controlled by adjusting the w value ([polar solvent]/[surfactant]) in the reverse-micelle solution, and the thickness of the silica shell is easily controlled by varying the amount of tetraethyl orthosilicate added after the synthesis of the magnetite cores. Several grams of monodisperse magnetite@silica nanoparticles can be synthesized without going through any size-selection process. When crosslinked enzyme molecules form clusters on the surfaces of the magnetite@silica nanoparticles, the resulting hybrid composites are magnetically separable, highly active, and stable under harsh shaking conditions for more than 15 days. Conversely, covalently attached enzymes on the surface of the magnetite@silica nanoparticles are deactivated under the same conditions.
Lee
Jinwoo
J
National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical Engineering, Seoul National University, Seoul 151-744, Korea.
Lee
Youjin
Y
Youn
Jong Kyu
JK
Na
Hyon Bin
HB
Yu
Taekyung
T
Kim
Hwan
H
Lee
Sang-Mok
SM
Koo
Yoon-Mo
YM
Kwak
Ja Hun
JH
Park
Hyun Gyu
HG
Chang
Ho Nam
HN
Hwang
Misun
M
Park
Je-Geun
JG
Kim
Jungbae
J
Hyeon
Taeghwan
T
D002384:Catalysis; D003432:Cross-Linking Reagents / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D012822:Silicon Dioxide / Q000737:chemistry*; D014961:X-Ray Diffraction
D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide