| Autor: |
Petcu G; Institute of Physical Chemistry 'Ilie Murgulescu', Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania., Ciobanu EM; Institute of Physical Chemistry 'Ilie Murgulescu', Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania., Paun G; National Institute for Research-Development of Biological Sciences, Centre of Bioanalysis, 296 Spl. Independentei, P.O. Box 17-16, 060031 Bucharest, Romania., Neagu E; National Institute for Research-Development of Biological Sciences, Centre of Bioanalysis, 296 Spl. Independentei, P.O. Box 17-16, 060031 Bucharest, Romania., Baran A; Institute of Physical Chemistry 'Ilie Murgulescu', Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania., Trica B; National Institute for Research & Development in Chemistry and Petrochemistry-ICECHIM, 202 Spl. Independentei, 060021 Bucharest, Romania., Neacsu A; Institute of Physical Chemistry 'Ilie Murgulescu', Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania., Atkinson I; Institute of Physical Chemistry 'Ilie Murgulescu', Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania., Bucuresteanu R; Microbiology Department, Faculty of Biology, University of Bucharest, Intr. Portocalelor 1-3, 060101 Bucharest, Romania., Badaluta A; Microbiology Department, Faculty of Biology, University of Bucharest, Intr. Portocalelor 1-3, 060101 Bucharest, Romania., Ditu LM; Microbiology Department, Faculty of Biology, University of Bucharest, Intr. Portocalelor 1-3, 060101 Bucharest, Romania., Parvulescu V; Institute of Physical Chemistry 'Ilie Murgulescu', Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania. |
| Abstrakt: |
Ag nanoparticles (AgNPs) were biosynthesized using sage ( Salvia officinalis L.) extract. The obtained nanoparticles were supported on SBA-15 mesoporous silica (S), before and after immobilization of 10% TiO 2 (Degussa-P25, STp; commercial rutile, STr; and silica synthesized from Ti butoxide, STb). The formation of AgNPs was confirmed by X-ray diffraction. The plasmon resonance effect, evidenced by UV-Vis spectra, was preserved after immobilization only for the sample supported on STb. The immobilization and dispersion properties of AgNPs on supports were evidenced by TEM microscopy, energy-dispersive X-rays, dynamic light scattering, photoluminescence and FT-IR spectroscopy. The antioxidant activity of the supported samples significantly exceeded that of the sage extract or AgNPs. Antimicrobial tests were carried out, in conditions of darkness and white light, on Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli and Candida albicans . Higher antimicrobial activity was evident for SAg and STbAg samples. White light increased antibacterial activity in the case of Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) . In the first case, antibacterial activity increased for both supported and unsupported AgNPs, while in the second one, the activity increased only for SAg and STbAg samples. The proposed antibacterial mechanism shows the effect of AgNPs and Ag + ions on bacteria in dark and light conditions. |
