Preparation of silica coated cobalt ferrite magnetic nanoparticles for the purification of histidine-tagged proteins

Download
2011
Aygar, Gülfem
The magnetic separation approach has several advantages compared with conventional separation methods; it can be performed directly in crude samples containing suspended solid materials without pretreatment, and can easily isolate some biomolecules from aqueous systems in the presence of magnetic gradient fields. This thesis focused on the development of new class of magnetic separation material particularly useful for the separation of histidine-tagged proteins from the complex matrixes through the use of imidazole side chains of histidine molecules. For that reason surface modified cobalt ferrite nanoparticles which contain Ni-NTA affinity group were synthesized. Firstly, cobalt ferrite nanoparticles with a narrow size distribution were prepared in aqueous solution using the controlled coprecipitation method. In order to obtain small size of agglomerates two different dispersants, oleic acid and sodium chloride, were tried. After obtaining the best dispersant and optimum experimental conditions, ultrasonic bath was used in order to decrease the size of agglomerates. Then, they were coated with silica and this was followed by surface modification of these nanoparticles by amine in order to add functional groups on silica shell. Next, –COOH functional groups were added to silica coated cobalt ferrite magnetic nanoparticles through the NH2 groups. After that Nα,Nα-Bis(carboxymethyl)-L-lysine hydrate, NTA, was attached to carboxyl side of the structure. Finally, nanoparticles were labeled with Ni (II) ions. The size of the magnetic nanoparticles and their agglomerates were determined by FE-SEM images, particle size analyzer, and zeta potential analyzer (zeta-sizer). Vibrational sample magnetometer (VSM) was used to measure the magnetic behavior of cobalt ferrite and silica coated cobalt ferrite magnetic nanoparticles. Surface modifications of magnetic nanoparticles were followed by FT-IR measurements. ICP-OES was used to find the amount of Ni (II) ion concentration that was attached to the magnetic nanoparticle.

Suggestions

Preperation and characterization of silica coated magnetite nanoparticles and labeling with nonradioactive Re as a surrogate of Tc-99m for magneticly targeted imaging
Zengin, Ümit; Volkan, Mürvet; Department of Chemistry (2010)
Magnetic nanoparticles have been used in many areas owing to their variable characteristic behaviors. Among these iron oxide nanoparticles are one of the mostly preferred type of nanoparticles. In this study Fe3O4, namely magnetite, which is one type of magnetic iron oxide nanoparticles was used. Magnetite nanoparticles with a narrow size distribution were prepared in aqueous solution using the controlled coprecipitation method. They were characterized by electron microscopic methods (SEM and TEM), crystal ...
The Effect of Ultrasonication on the Size and Morphology of Iron Oxide - Chitosan Nano and Microparticles
Akin, Deniz; YAKAR, ARZU; Gündüz, Ufuk (2013-04-28)
The aim of this study is to synthesize magnetic Fe3O4-chitosan nano and microparticles (Fe3O4-CPs) by suspension cross-linking and ionic gelation methods and investigate the effect of ultrasonication on the size, morphology and magnetic properties. The synthesized particles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and vibrating sample magnetometry (VSM). The results showed that the ultrasonication decreased the mean particle diameter and enhanced magnetic ...
Synthesis and Characterization of Polyhydroxybutyrate Coated Magnetic Nanoparticles: Toxicity Analyses on Different Cell Lines
Yalcin, Serap; Khodadust, Rouhollah; Unsoy, Gozde; Garip, Immihan Ceren; Mumcuoglu, Zahide Didem; Gündüz, Ufuk (2015-01-01)
In this study, polyhydroxybutyrate (PHB) coated magnetic nanoparticles were prepared which are targetable to tumor cells in the presence of a magnetic field. The structural properties, functional groups, size distribution, and magnetic properties of the synthesized PHB coated magnetic nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectrometer, transmission electron microscopy, dynamic light scattering, vibrating sample magnetometry, and thermogravimetric analysis. PHB coa...
Large structure-dependent room temperature exchange bias in self-assembled BiFeO3 nanoparticles
Goswami, Sudipta; Sahoo, Aditi; Bhattacharya, Dipten; Karci, Ozgur; Mohanty, P. K. (2020-08-01)
We studied the magnetic properties of self-assembled aggregates of BiFeO3 nanoparticles (similar to 20 nm-40 nm). The aggregates formed two different structures-one with limited and another with massive crosslinking-via the "drying-mediated self-assembly" process following dispersion of the nanoparticles within different organic solvents. They exhibit large coercivity H-C (>1000 Oe) and exchange bias field H-E (similar to 350-900 Oe) in comparison to what is observed in isolated nanoparticles (H-C similar t...
Characterization of dual-phase steels using magnetic barkhausen noise technique
KAPLAN, MÜCAHİT; Gür, Cemil Hakan; Erdogan, METEHAN (Springer Science and Business Media LLC, 2007-12-01)
The aim of this work is to nondestructively characterize the dual phase steels using the Magnetic Barkhausen Noise (MBN) method. By quenching of AISI 8620 steel specimens having two different starting microstructures, from various intercritical annealing temperatures (ICAT) in the ferrite-austenite region, the microstructures consisting of different volume fractions of martensite with morphological variations have been obtained. The microstructures were first conventionally characterized by metallographical...
Citation Formats
G. Aygar, “Preparation of silica coated cobalt ferrite magnetic nanoparticles for the purification of histidine-tagged proteins,” M.S. - Master of Science, Middle East Technical University, 2011.