RESEARCH PAPER High-performance antibacterial of montmorillonite decorated with silver nanoparticles using microwave- assisted method Zeinab Mohamed Hassan Kheiralla • Abeer Ahmed Rushdy • Mohamed Ahmed Betiha • Naglaa Abdullah Nasif Yakob Received: 19 February 2014 / Accepted: 8 July 2014 / Published online: 29 July 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract Syntheses of silver nanocomposites (Ag- NPs@MMT) were fabricated with different silver nanoparticles to montmorillonite clay (MMT) ratios using microwave-assisted synthesis method, and silver nitrate was used as the precursor of silver nanoparticles. The antibacterial activities of the nanocomposite were evaluated against Staphylococcus aureus and Pseudo- monas aeruginosa bacteria by the disk diffusion and macrodilution broth techniques. The prepared nano- composites were characterized by N 2 adsorption– desorption isotherms, X-ray diffraction (XRD), field emission scanning electron microscope, high-resolution transmission electron microscope (HRTEM), X-ray fluorescence spectroscopy and Fourier transform infra- red spectroscopy. The wide-angle XRD patterns and HRTEM images demonstrate that silver nanoparticles were fabricated on surface and within MMT channels. The diameters of the AgNPs were below 15 nm, as indicated by UV–Vis absorption, which effectively controlled by the pores of the MMT host. Data revealed that 5 % AgNP@MMT nanocomposite is much more effective than silver nitrate and shows strong antibac- terial activities. The efficiency of antibiotics increased when combined with 5 % AgNP@MMT nanocompos- ite against both the tested strains. The increase in fold area was higher in case of P. aeruginosa than S. aureus. The highest percentage of fold increases was found for Sulfamethaxole/Trimethoprim and Oxacillin followed by Levofloxaci and Nalidixic acid against P.aeruginosa. On the other hand, Imipenem increases activity in presence of AgNP@MMT nanocomposite against S. aureus. Overall, the synergistic effect of antibiotics and nanoparticles clearly revealed that nanoparticles can be effectively used in combination with antibiotics in order to improve their efficiency against various pathogenic microbes. The suspensions of the synthesized nano- composites were found to be stable over a long time without any sign of detachment of AgNPs. Keywords Silver nanoparticles  Microwave synthesis  Montmorillonite clay (MMT)  Antibacterial activity  Nanocomposite materials Introduction Antibacterial agents and materials play important roles in treating infectious diseases caused by Z. M. H. Kheiralla  A. A. Rushdy (&)  N. A. N. Yakob Botany Department- Faculty of Women for Arts, Science and Education Ain Shams University, Asmaa Fahmy Street Heliopolis, Cairo 11586, Egypt e-mail: abeerahmedr@gmail.com Z. M. H. Kheiralla e-mail: kheiralla@hotmail.com N. A. N. Yakob e-mail: lovelynoga_2000@yahoo.com M. A. Betiha Egypt Refining Division, Egyptian Petroleum Research Institute, Cairo, Egypt e-mail: Mohamed_betiha@hotmail.com 123 J Nanopart Res (2014) 16:2560 DOI 10.1007/s11051-014-2560-6