Silver Nanoparticles Stabilized by Oligomeric Hyperbranched Ionic Liquid: Structure and Antimicrobial Properties

Abstract

The peculiarities of the structural organization of silver nanoparticles (AgNP) and their antimicrobial properties were studied using the methods of FTIR spectroscopy, X-ray analysis, electron microscopy and the disc-diffusion method. In this paper, for the first time, an anionic oligomeric ionic liquid with a hyperbranched structure developed by us was used as a surface stabilizer in the synthesis of AgNP. The synthesis of AgNP was carried out by reducing Ag ions in AgNO3 with trisodium citrate in the presence of this ionic liquid. It was established that there are adsorbed ionic and carbonyl groups on the surface of the formed AgNP, and the formation of complexes between the ionic liquid and silver ions was revealed. According to electron microscopy, the size of the synthesized nanoparticles varies from 8 to 22 nm, with an average value of 14.2 nm. The synthesized silver nanoparticles showed a very high antimicrobial activity against C. albicans fungi, while the width of the inhibition zone (d) was 34 mm. In addition, the powder of AgNP shows a very high activi-ty against gram-positive bacteria S. aureus (d = 30 mm) and gram-negative bacteria E. coli (d = 10 mm).