Synthesis and synergistic effect of antibacterial composites based on concentrated hydrosols of silver nanoparticles combined with cephalosporins antibiotics

Vorobyev, S.A., Novikova, G.V., Demina, A.V., Shidlovskiy, I.P., Volochaev, M.N.// Inorganic Chemistry Communications//

Silver nanoparticles may be used as potential antimicrobial agents. Concentrated silver nanoparticles (AgNPs) were synthesised by the Carey Lee method. Then, antibiotics, such as disodium ceftriaxone, sodium cefotaxime, sodium cefazolin and sodium cefoperazone, were added to the AgNPs at the ratio of AgNPs:antibiotic = 5:1. The concentrated hydrosols were examined using UV–Vis, FTIR-spectroscopy, dynamic light scattering and transmission electron microscopy. The spectra plasmon resonance of silver nanoparticles and their combination with antibiotics had a single strong peak at 412–415 nm. The transmission electron microscopy micrographs showed different forms. The average size of AgNPs-antibiotic particles was smaller than that of AgNPs. The antibacterial activities of AgNPs, antibiotics and AgNPs-antibiotics were determined by the disk diffusion method against Staphylococcus aureus and Escherichia coli. The most significant enhancement of the antibacterial effect over the antibiotic was demonstrated by AgNPs-disodium ceftriaxone against E.coli. Also, the minimal inhibitory concentration (MIC) of the AgNPs-antibiotics was defined. All the AgNPs-antibiotic exhibited a synergistic enhancement by AgNPs and the antibiotic of antibacterial activity. A possible explanation of this phenomenon was proposed. Our results suggest that the synthesis of the concentrated hydrosol of the AgNPs-antibiotics is essential for studying similar nanosystems.