Surface functionalization of silica-coated magnetic nanoparticles for covalent attachment of cholesterol oxidaseŠulek, Franja ...A systematic approach towards the fabrication of highly functionalized silica shell magnetic nanoparticles, presently used for enzyme immobilization, is herein fully presented. The synthesis of bare ... maghemite (y-Fe2O3) nanoparticles was accomplished by thermal co-precipitation of iron ions in ammonia alkaline solution at harsh reaction conditions, respectively. Primary surface engineering of maghemite nanoparticles was successfully performed by the proper deposition of silica onto nanoparticles surface under strictly regulated reaction conditions. Next, the secondary surface functionalization of the particles was achieved by coating the particles with organosilane followed by glutaraldehyde activation in order to enhance protein immobilization. Covalent immobilization of cholesterol oxidase was attempted afterwards. The structural and magnetic properties of magnetic silica nanocomposites were characterized by TEM and vibrating sample magnetometer (VSM) instruments. X-ray diffraction measurements confirmed the spinel structure and average size of uncoated maghemite nanoparticles to be around 20nm in diameter. SEM-EDS spectra indicated a strong signal for Si, implying the coating procedure of silica onto the particles surface to be successfully accomplished. Fourier transform infrared (FT-IR) spectra analysis confirmed the binding of amino silane molecules onto the surface of the maghemite nanoparticles mediated Si-O-Si chemical bonds. Compared to the free enzyme, the covalently bound cholesterol oxidase retained 50% of its activity. Binding of enzyme onto chemically modified magnetic nanoparticles via glutaraldehyde activation is a promising method for developing biosensing components in biomedicine.Source: Journal of Magnetism and Magnetic Materials. - ISSN 0304-8853 (Vol. 322, iss. 2, Jan. 2010, str. 179-185)Type of material - article, component partPublish date - 2010Language - englishCOBISS.SI-ID - 13418262
biomedicina | encimi | imobilizacija encimov | obstojnost encimov | nanodelci | magnetni nanodelci | površinska funkcionalizacija | magnetic nanoparticles | maghemite nanoparticles | surface functionalization | enzyme immobilization
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Select the library membership card:
DRS, in which the journal is indexed
Select pickup location:
Material pickup by post
Subject headings in COBISS General List of Subject Headings
Select pickup location
Please wait a moment.