a Physics Department / College of Education for Pure Science / Tikrit University/ Iraq

^bPhysics Department /College of Science / Mustansiriyah University / Baghdad/

Iraq

There are several ways to produce nanoparticles, but the pulsed laser method with deionized water has been found to be the easiest. All materials change over time and nanoparticles NPs can “age” during storage, and the effect of this may lead to varying results in terms of observed toxicity for nominally the same NPs. The aim of the study was to determine whether (and to what extent) changes in the properties of SeO2 NPs occur over time. Spherical and clustered selenium dioxide nanoparticles SeO2 NPs were synthesized using pulsed laser ablation in deionized water, and using a pulsed Nd:YAG laser with an energy of 400 mJ and 200 pulses. The topographic, compositional, morphological and optical properties of SeO2NPs were studied using AFM, ultraviolet spectroscopy, XRD, SEM, and the optical energy gap of the generated SeO2 nanoparticles was evaluated using optical properties to measure UV-vis was found to be close to 3.37 Ve. The XRD patterns also show that the as-synthesized SeO2 NPs are Nano crystals and have face-centered cubic FCC. The prepared solutions were used to inhibit the reproduction of bacteria and fungi Staphylococcus aurous, Staphylococcus epidermises, Escherichia coli, Klebsiella Pneumoniae and Candida albicans. respectively. Preliminary results were compared. With the results we obtained after 90 days of producing the solution, it was found that the inhibition decreased to a maximum of 36% for Staphylococcus aurous bacteria. The CL-40 colon cancer cell line was used to investigate the toxicity of the produced selenium nanoparticles. Se NPs' IC50 value for CL-40 was found to be 237 μg/mL, and a dose-dependent reduction of cell viability was noted.