Correspondence: Viara Ivanova University of Food Technologies – Plovdiv, Department of Microbiology, 26 Maritsa Blvd., 4002 Plovdiv, Bulgaria. Tel.: +359 32 603622 e-mail: [email protected] ABSTRACT Recombinant cyclodextrin glucanotransferase JCGT8-5 (CGTase, EC 2.4.1.19) was effectively immobilized by formation of chemical bounds on polyethylenimine (PEI)-activated silica particles, on silaniz...

Nanoparticles containing magnetic materials, such as magnetite (Fe3O4), are particularly useful for imaging and separation techniques. As these nanoparticles are generally considered to be biologically and chemically inert, they are typically coated with metal catalysts, antibodies or enzymes to increase their functionality as separation agents. Here, we report that magnetite nanoparticles in f...

The effect of maghemization on the magnetic properties of magnetite (Fe3O4) grains in the pseudo-single-domain (PSD) size range is investigated as a function of annealing temperature. X-ray diffraction and transmission electron microscopy confirm the precursor grains as Fe3O4 ranging from 150 to 250 nm in diameter, whilst M€ ossbauer spectrometry suggests the grains are initially near-stoichiom...

Humic substances (HS) are redox-active compounds that are ubiquitous in the environment and can serve as electron shuttles during microbial Fe(III) reduction thus reducing a variety of Fe(III) minerals. However, not much is known about redox reactions between HS and the mixed-valent mineral magnetite (Fe3O4) that can potentially lead to changes in Fe(II)/Fe(III) stoichiometry and even dissolve ...

This work is devoted to the preparation of magnetite-covered clay particles in aqueous medium. For this purpose, magnetite nanoparticles were synthesized by a coprecipitation method. These magnetic particles are adhered to sodium montmorillonite (NaMt) particles in aqueous suspensions of both materials, by appropriate control of the electrolyte concentrations. The best condition to produce such...

Hematite (α-Fe2O3) and magnetite (Fe3O4) nanowires with the diameter of about 100 nm and the length of tens of micrometers have been selectively synthesized by a microemulsion-based method in combination of the calcinations under different atmosphere. The effects of the precursors, annealing temperature, and atmosphere on the morphology and the structure of the products have been investigated. ...

Although there is extensive literature covering the biomedical applications of superparamagnetic iron oxide nanoparticles (SPIONs), the phase of the iron oxide core used is not often taken into account when cell labelling and tracking studies for regenerative medicine are considered. Here, we use a co-precipitation reaction to synthesise particles of both magnetite- (Fe3O4) and maghemite- (γ-Fe...

objective(s): this paper describes coating of magnetite nanoparticles (mnps) with amorphous silica shells.   materials and methods: first, magnetite (fe3o4) nps were synthesized by co-precipitation method and then treated with stabilizer molecule of trisodium citrate to enhance their dispersibility. afterwards, coating with silica was carried out via a sol-gel approach in which the electrostati...

DOI: 10.1002/sscp.202200026 This cover picture shows the applicability of Mobil catalytic material number 4 modified magnetite nano-composites (MCM-41@Fe3O4) in magnetic solid phase extraction (MSPE). MCM-41@Fe3O4 as MSPE was first added to sample solution NSAIDs containing diclofenac, ketoprofen, and mefenamic acid. After 5 min incubation, can be separated using a field. Further, supernatant c...