Physicists Obtain Substances for Biomedicine and Photocatalysts

13:47, June 20, 2023

They can be used for safe diagnostics or to clean water of harmful contaminants

Russian scientists have obtained magnetite nanoparticles (a mineral, a magnetic modification of iron oxide) from the non-magnetic source iron vitriol. Physicists managed to synthesize such particles for the first time using the radiation-chemical method. As a result, nanoparticles are magnetized in an external magnetic field (such substances are called paramagnetic) and can be used as contrast agents in magnetic resonance imaging and photocatalysis. An article by the scientists describing their research and results was published in the journal Ceramics International. The work was supported by the Russian Science Foundation (Project No. 22-19-00239).

"First, because magnhemite is a magnetic material, its nanoparticles are clearly distinguishable in a magnetic field despite their small size. Second, magnhemite nanoparticles are so small that they do not clog blood vessels when injected into the human body. Third, as a modification of iron oxide, maghemite interacts well with hemoglobin, an iron-containing protein. Most importantly, unlike gadolinium, which is traditionally used as a contrast agent, maghemite is a completely non-toxic substance. Thus, the use of magnetite nanoparticles will make it possible to carry out MRI scans with higher quality, efficiency and safety," says Sergey Sokovnin, head of the research team, Professor of the UrFU Department of Experimental Physics, leading researcher of the Institute of Electrophysics, Ural Branch of the Russian Academy of Sciences.

Another possible application of the obtained magnetite nanoparticles is photo- and radiation-induced catalysis. In other words, the acceleration of chemical reactions under the influence of ultraviolet or X-rays. Studies carried out by the authors of the article showed that when magnesite nanoparticles are used as a catalyst, the reaction rate more than doubles. While maintaining the same rate, the dose of radiation and consequently the cost of the reaction is reduced accordingly.

According to Sergey Sokovnin, this effect can be used in particular to purify water from chemical impurities. In this field of application, maghemite is not inferior to the most productive industrial catalyst - titanium oxide.

"Basic iron oxides, such as maghemite and hematite, are constantly in the focus of science because of their outstanding magnetic, optical and electrical properties. They are used not only as non-toxic contrast agents and photocatalysts, but also as nanocontainers for drug delivery, magnetic carriers, gas sensors, and so on. Maghemite in particular is considered to be one of the most interesting iron oxides. It is particularly promising for use in biomedicine, including cancer treatment, because it is non-toxic to healthy cells and has a negative effect on cancer cells. At the same time, the synthesis of iron oxide nanoparticles in aqueous solutions, whose magnetic modification is maghemite, remains a difficult task," Sergey Sokovnin explains the importance of the work performed.

The scientists carried out the synthesis of maghemite using the radiation-chemical method, in which an aqueous solution of iron sulfate crystals is irradiated with accelerated electrons. This method produces nanopowders with a high concentration of structural defects, on which many interesting and useful properties often depend. As a result of irradiation, nanopowders have been obtained that contain both the amorphous phase of maghemite and its ultrafine crystals of about 2-3 nanometers in size.

Reference

Employees of the departments of the Ural Federal University, the Ural Branch of the Russian Academy of Sciences, St. Petersburg State University and Omsk State Technical University participated in the research.

The news article was translated by UrFU International Marketing Office. 
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