Scientists have developed custom-shaped nanoparticles
Physicists from the Ural Federal University (UrFU) and their colleagues from the Institute of Electrophysics of the Ural Branch of the Russian Academy of Sciences and the Institute of Ion Plasma Technologies and from the laser of the Academy of Sciences of Uzbekistan have developed a technology for the growth of non-spherical particles. nanoparticles that are synthesized during the ion implantation process. The new technique makes it possible to grow nanoparticles of different shapes and thus to obtain the necessary properties and to control these properties. The technology is applicable to various metals, both noble metals such as gold, silver and platinum, as well as “ordinary” metals, say the scientists. A description of the technology and the results of the first experiments – implantation of copper in ceramics –published in the Journal of Solid State Physics and Chemistry.
“By changing the shape of the nanoparticles from spherical to non-spherical, we were able to increase the optical absorption range. This, in turn, is the basis for further conversion of the absorbed energy into electricity, into heat. As a result, we can obtain more functional sensors and increase their sensitivity range,” says study co-author Arseny Kiryakov, associate professor at the UrFU Department of Physical Methods and Quality Control Devices. “If such nanoparticles are integrated into lasers, the power of the lasers will increase. If we talk about sensors, their sensitivity will increase. As for the sensors, their response time will change. All this is due to the particularity of plasmon resonance, which causes the appearance of an amplified electric field around the nanoparticles.
Metallic nanoparticles are used to solve various problems: from biological (sensors to determine the composition of proteins, DNA analysis, etc.) to physical (creation of amplified lasers, photoluminescent sensors, etc.). Thus, in contact with bioobjects – DNA, viruses, antibodies – plasmonic nanostructures allow an increase of more than one order of magnitude [to] the intensity of fluorescence signals, i.e. significantly increasing detection, identification and diagnostic capabilities. And changing the shape of the nanoparticles will make it possible to control these properties, to improve them.
Early experiments with copper particles allowed scientists to create a metamaterial that has no analogues.
“The new material consists of non-spherical plasmonic nanoparticles in a matrix of optically transparent radiation resistant ceramics. The controlled morphology of plasmonic nanoparticles provides enhanced spectral characteristics and increases the energy conversion efficiency of absorbed photons,” says Anatoly Zatsepin, professor in the Department of Physical Methods and Quality Control Devices at UrFU. “We discovered that the unique physical properties of the resulting material…appear through a special phenomenon – the surface plasmon resonance effect.”
Moreover, a co-researcher from Uzbekistan proposed a universal mathematical model describing this process. According to the physicists, the model is important for describing and understanding what happens to nanoparticles in different materials, and it is the first model that describes the growth of non-spherical nanoparticles. Previous models do not take into account the unusual shape of the particles.
Physicists plan to expand their understanding of the nature and laws of physical phenomena occurring in the material under external energy influences, which, in turn, will provide information on new possibilities of functional application of this type of materials.
– This press release was provided by Ural Federal University