Search

Carbon nanomaterials are ground-breaking two-dimensional materials with a wide range of applications because of their unique properties, which include excellent optical, electrical, thermal, and mechanical capabilities; biocompatibility; and inexpensive large-scale production costs. In this study, carbon nanostructural materials (CNMs) were effectively generated using a pulsed laser ablation method on a graphite target immersed in deionized water, and their cytotoxicity and antibacterial activities were evaluated. Lasing pulse duration, ns (1064 nm) with different laser energies (60-220 mJ), was employed for irradiating the target. The formation of CNMs was analyzed using Fourier transform infrared spectroscopy, which demonstrated that C–H, C–C, C–O, and C=C bonds were successfully formed. TEM micrographs observed CNM formation with a spherical shape and size ranging from 20 to 90 nm. The absorbance was measured using UV-Vis spectroscopy; it increased with increasing laser energy showing two broad shoulders around 210 and 305 nm. Thereafter, the antibacterial activity was tested against Escherichia coli and Staphylococcus aureus using the agar method. The results indicated that CNMs fabricated at laser energy 220 mJ have the highest activity against both strains and have presented inhibition zone (IZ) of about 34 ± 1.0 mm in S. aureus and 31 ± 1.5 mm for E. coli. A comparison with CNMs prepared at 160 mJ showed an IZ of 14 mm for S. aureus and of 12 mm for E. coli due to synergistic impact, while the cellular material release analysis displayed increased release with respect to the time of exposure due to inhibition of bacterial growth. [ABSTRACT FROM AUTHOR]

Green nanoparticle synthesis is an environmentally friendly approach that uses natural solvents. It is preferred over chemical and physical techniques due to the time and energy savings. This study aimed to synthesize zinc oxide nanoparticles (ZnO NPs) through a green method that used Phlomis leaf extract as an effective reducing agent. The synthesis and characterization of ZnO NPs were confirmed by UV-Vis spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic light scattering (DLS), Zeta potential, and Field Emission Scanning Electron Microscope (FESEM) techniques. In vitro cytotoxicity was determined in L929 normal fibroblast cells using MTT assay. The antibacterial activity of ZnO nanoparticles was investigated using a disk-diffusion method against S. aureus and E. coli, as well as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) content concentrations. XRD results confirmed the nanoparticles' crystalline structure. Nanoparticle sizes were found to be around 79 nm by FESEM, whereas the hydrodynamic radius of nanoparticles was estimated to be around 165 ± 3 nm by DLS. FTIR spectra revealed the formation of ZnO bonding and surfactant molecule adsorption on the surface of ZnO NPs. It is interesting to observe that aqueous extracts of Phlomis leave plant are efficient reducing agents for green synthesis of ZnO NPs in vitro, with no cytotoxic effect on L929 normal cells and a significant impact on the bacteria tested. [ABSTRACT FROM AUTHOR]