Synergistic antibacterial effects of nano zinc oxide combined with silver nanocrystales

Abstract

Antibacterial nanocrystals have attracted great interests in recent years. In fact, with the emergence and increase of microbial organisms resistant to multiple antibiotics, many researchers have tried to develop new antibiotics. The aim of this research is to compare antibacterial activity of mono-metallic with composite nanocrystals, againstEscherichia coli, Salmonella galinarium, Staphylococcus aureus, Pesudomonas aueroginosa, and Bacillus subtilis, with and without sonication, for the first time. Mono-metallic with composite nanocrystals, are synthesized via wet method and ensure with oxalate decomposition in high temperature (500°C). FT-IR, XRD, SEM were used for determination of spectroscopic, structural and morphology of samples, respectively. Also the nanoparticls were digested and analyzed by ICP-AES for determining the presence of residual chemical element in the nanoparticles, after sonication. Bacterial sensitivity to nanocrystals, with and without sonication, were commonly tested using disc diffusion test and agar dilution test, also with determination of minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The particles size was less of 100 nm, approximately. This study shows that synthesis of mono-metallic and composite nanocrystals, with oxalate decomposition method is simple and so useful. Although, we confirmed that utilized of the ultrasonic vibration were futile, entirely. Also, the Ag/ZnO nanocrystals have great antimicrobial agent against all of the strains and just combination of zinc oxide and silver nanocrystals, give increase their bactericidal effect. Key words: Antibacterial activity, Ag/ZnO, nanocomposite, synergistic antibacterial activities.