فعالية المضاد البكتيري لاكاسيد المعادن النانوية المحضرة بواسطة الاستئصال بالليزر في سائل == Antibacterial Activity of Metals Oxide Nanoparticles Induced by Laser Ablation in Liquid
Author name:
فرح عبد الكريم عبد الامير
Supervisor name:
خولة صلاح خشان | غسان محمد سلمان
General topic:
Laser Science
Specific topic:
Laser Applications in Physics
Degree:
Master
University:
University of Technology
Language:
English
University location:
Baghdad
First pages:
29T205 - p.pdf
Abstract:
With the increasing of bacterial resistance against antibiotics, nanoparticles studies was appeared together with growing need for substituting theseantimicrobial agents. Recently, it has been demonstrated that metal oxides nanoparticles exhibits bactericidal effect against both bacteria strains.In this research, three kinds of metal oxide nanoparticles (Nickel oxide, Copper oxide and Titanium dioxide) colloidal solutions synthesized using laser ablation of nickel, copper and titanium pellet immersed in de - ionized water. Pulsed Nd : YAG laser with 1٠٦٤ nm wavelength and different laser energies (40, 80, 120, 160 and 200 mJ) was used to irradiate the targets for various ablation times : 5 (75 pulse), 10 (150 pulse), 15 (225 pulse) and 20 min (300 pulse).The UV - Visible absorption spectrum of NiO nanoparticles exhibited broad bands whose intensity decreased continuously above ~210 nm. The UV - Visible absorption spectrum of the CuO nanoparticles solution showed absorption peak around ~275 nm and another peak with low intensity around ~645 nm. While absorption spectrum of TiO2 nanoparticles exhibited strong absorption domination on the spectrum below ~360 nm. In all three metal oxide nanoparticles, absorption intensity increased with the laser energy and ablation time due to increase nanoparticles concentrations in liquid. Fourier Transform Infrared spectroscopy characterization confirmed the formation of metal oxide nanoparticles. All three metal oxides nanoparticles gave absorption bands below ~600 cm−1 arising from inter - atomic vibrations. X - ray Diffraction pattern of nanoparticles proved the presence of (111), (200) planes which belong to NiO and ( - 111), (112) planes that assigned to CuO and (101), (112), ( - 403) planes that related to TiO2. TransmissionElectron Microscopy measurement showed NiO, CuO and TiO2 nanoparticles with nearly spherical shapes and sizes at 2 - 21 nm, 3 - 40 nm and 6 - 30 nm respectively.The antibacterial activity of nanoparticles carried out against four types of bacteria : Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris (gramnegative bacteria), Staphylococcus aureus (gram - positive bacteria) firstly by liquid medium method. 1000 μg ml - 1 concentration was the best - used concentration of nanoparticles for inhibiting growth of both bacteria strains. Among the three tested types of nanoparticles (NiO, CuO and TiO2) at highest concentration (1000 μg ml - 1), TiO2 NPs showed the highest antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. NiO NPs showed the highest antibacterial activity against Staphylococcus aureus while CuO NPs showed the highest antibacterial activity against Proteus vulgaris. Results also indicated that metal oxide nanoparticles and amoxicillin would have a synergistic effect on inhibiting of bacterial growth. Amoxicillin showed inhibitory rate about 74.8% against Escherichia coli and 76.28% against Staphylococcus aureus. In the case of NiO, CuO and TiO2 nanoparticles at concentration 1000 μg ml - 1 with Amoxicillin, antibacterial activity of Amoxicillin enhanced to about 81.5%, 90% and 81.9% against Escherichia coli and to about 86.9%, 91% and 90.7% against Staphylococcus aureus. Therefore, CuO nanoparticles and amoxicillin have the best synergic effect on inhibiting both bacteria strains. The antibacterial activity of the three metal oxides nanoparticle combined with Amoxicillin was also tested by well diffusion method against Escherichia coli and Staphylococcus aureus. In this method, CuO NPs at concentration 1000 μg ml - 1 along with Amoxicillin showed the highest inhibition zone against Escherichia coli (26.0±1.00 mm), while showed complete inhibition of bacteria against Staphylococcus aureus.
