Enhanced Antibacterial Activity of Selenium Nanoparticles Prepared by Cold Plasma in Liquid

In this study, selenium Nanoparticles were synthesized using selenium nitrate in a physical way (using cold plasma produced under normal atmospheric pressure) operating on alternating current AC with a voltage of (13) kV. Its frequency is (23) kHz, and the speed of the Argon gas flow is (3) L/min with an exposure time of 3 min. Selenium Nanoparticles were prepared in four different concentrations (0.2, 0.4, 0.6, and 0.8 ) mM, then the selenium Nanoparticles were characterized by UV-VIS spectroscopy, where (absorption, transmittance, absorption coefficient, energy gap) were measured for all concentrations where it was observed The absorbance increased with the increase in the concentration of the material, while the permeability decreased. The energy gap was at the lowest concentration, 1.74 electron volts. With the increase in concentration, it was noticed that the energy gap decreases, and this is due to the transformation of the material to the nanoscale. Nanoparticle characteristics have been investigated (XRD, AFM, FESEM, and UV-Vis). The biological activity of selenium Nanoparticles was tested by the method of diffusion in the medium towards Gram-positive bacteria Klebsiella Pneumoniae and Gram-negative Staphylococcus. aureus, where the highest inhibition rate was recorded for Gram-negative bacteria, reaching (31, 30, 20, 22) mm, respectively, in the case of bacteria. The positive amount reached (29, 24, 24 20) mm, respectively, where it was noticed that the concentration of the substance increased, the rate of the inhibition diameter increased.