Nanocomposites and nanomaterials

New approaches to the synthesis of precious metal nanoparticles
SemenivV.S. 1,2, Berezhnytska O. 1,2, Khrokalo L.A. 2, Trunova O. 1
1V.I.Vernadsky Institute of General and Inorganic Chemistry NASU, Kyiv, Ukraine E-mail: vikysia1202@gmail.com
2National Technical University of Ukraine “Igor Sikorsky Kiev Polytechnic Institute”, Peremohy ave., Kyiv, 3703056, Ukraine 

The antibacterial properties of silver have been known since ancient times, but the use of silver nanoparticles in medicine and cosmetology began not too long ago. Many scientists have focused on the synthesis of nanosilver. There are conflicting opinions about the properties of nanoparticles. Some consider these properties unique, others say about the high toxicity of such systems. Nanoparticles of silver and gold are obtained by reducing their salts in weakly alkaline solutions in the presence of surfactants. Sodium borohydride, citric acid, glucose, aniline and the like are used as reducing agents. In this case, the formation of nanoparticles begins during the synthesis and ends in a few hours, which is reflected in the change in color of the solution. The dispersed systems thus obtained have a bright color due to their plasmon resonance absorption. 
The paper considers a new approach to the synthesis of silver and gold nanoparticles. The essence of the research is the formation of metal nanoparticles stabilized by the deprotonated complexonate of the corresponding metals. A study of complexation in the Agedta, Agedds, Auedta, Auedds systems was carried out. It was shown that chelating agents (ethylenediaminetetraacetate and ethylenediaminedisuccinate) exhibit high reducing properties; however, not only metal nanoparticles but also metal complexes are formed in the solution. The presence of an SPR band in the EAS and a change in the color of solutions indicates the existence of silver and gold nanoparticles in the systems. It was established by the method of dynamic light scattering that all the obtained systems are nanosystems with a uniform distribution of the dispersed phase in the dispersion medium. The studies of the biological activity showed that all the studied powders showed an inhibitory effect on the growth of bacteria. The highest inhibitory effect was recorded for Auedta on E. coli culture. Gold nanosystems were found to be more active than silver systems against bacteria of both strains.