• Title/Summary/Keyword: silica-coated magnetite nanoparticles

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Effect of functional group on activity and stability of lipase immobilized on silica-coated magnetite nanoparticles with different functional group (실리카 코팅된 자성 나노입자로의 효소 고정화에 사용된 작용기가 리파아제의 활성과 안정성에 미치는 영향)

  • Lee, Hye Rin;Kim, Moon Il;Hong, Sang Eun;Choi, Jaeyeong;Kim, Young Min;Yoon, Kuk Ro;Lee, Seungho;Ha, Sung Ho
    • Analytical Science and Technology
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    • v.29 no.3
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    • pp.105-113
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    • 2016
  • The present study investigated the immobilization of lipases on silica nanoparticles and silica-coated magnetite nanoparticles as supports with a functional group to enhance the stability of lipase. The influence of functional groups, such as the epoxy group and the amine group, on the activity and stability of immobilized lipase was also studied. The epoxy group and the amino group were introduced onto the surface of nanoparticles by glycidyl methacrylate and aminopropyl triethoxysilane, respectively. Immobilized Candida rugosa lipase on silica nanoparticles and silica-coated magnetite nanoparticles with a functional group showed slightly lower initial enzyme activities than free enzyme; however, the immobilized Candida rugosa lipase retained over 92 % of the initial activity, even after 3 times reuse. Lipase was also immobilized on the silica-coated magnetite nanoparticles by cross-linked enzyme aggregate (CLEA) using glutaraldehyde and covalent binding, respectively, were also studied. Immobilized Candida rugosa lipase on silica nanoparticles and silica-coated magnetite nanoparticles by CLEA and covalent binding showed higher enzyme activities than free enzyme, while immobilized Candida rugosa lipase retained over 73 % of the initial activity after 5 times reuse.

Synthesis and Characterization of Superparamagnetic Fe3O4@SiO2 Nanoparticles

  • Kulkarni, Sachnin A.;Sawadh, P.S.;Palei, Prakash K.
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.100-104
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    • 2014
  • Magnetite nanoparticles were prepared by co-precipitation method and then silica was coated onto the surface of $Fe_3O_4$ by hydrolysis of TEOS. The silica coated magnetite nanoparticles were characterized for its structural, microstructural, optical, vibrational and magnetic properties by X-ray diffraction analysis, Scanning electron microscopy, UV-visible spectroscopy, Infrared spectroscopy and Vibration sample magnetometer, respectively. XRD study confirmed the presence of $SiO_2$ on the surface of magnetite nanoparticles. SEM study indicated that with increase in TEOS content the particles become bigger and mono-disperse. It was also found that the silica coating prevents magnetic particles from aggregation and imparts excellent stability.