ИСТИНА

Magnetite nanoparticles Fe3O4(MNP)are widely applied in biomedical research, namely for improvement the contrast range ofMRI, immunoassay, etc. In the scientific publications, the magnetic nanoparticles are proposed to use for treatment of cancer by targeted drug delivery. MNP could carry the specific drug to a tumor along the bloodstream and release it by magnetic field (MF).Moreover, the magnetic nanoparticles can influence on the chemical reactions in the body, for example, on enzymaticreactions. A combination of those ideas is being considered in the current report as pretty attractive and relevant things for humanity. The active site of enzyme immobilized on the nanoparticles can be deformed by their rotation under magnetic field exposure without heating. This rotation may be initiated by exposure to low frequent(LF) alternating magnetic field (50-100 Hz).The reorientation of magnetic moments of Fe3O4 in nanoparticles (d>6 nm)exposed into MF leads to the rotationof magnetic particles on Brown mechanism. Once the enzyme is deformed, itwill leave nominal catalytic activity. But Fe3O4 are toxic and could rapidly aggregate without stabilizers. That is why an important issue of the work performed with MNPs is the development of methods of covering the magnetic core. For example, MNPs coated with gold shell possess low toxicity in the body, show less ability to aggregate and can easily be functionalized with different organic ligands via SH-groups. This paper presents a synthesis of magnetic (Fe3O4)and magnetic gold particles (Fe3O4@Au) with the core-shell structure, confirmedby micrographs EPMA (electron probe microanalyzer).For the surface functionalization of nanoparticleslipoicand dimercaptosuccinicacids were used as organic ligands. The results of nanosystem studying represent some approaches to description of nanoconjugates (NP-enzyme-) and the effect of LFMF on catalytic activity of immobilized enzymes via such linkers.