Toxicological Impact Studies Based on Escherichia coli Bacteria in Ultrafine ZnO Nanoparticles Colloidal Medium

We report here preliminary studies of biocidal effects and cellular internalization of ZnO nanoparticles on Escherichia coli bacteria. ZnO nanoparticles were synthesized in di(ethylene glycol) (DEG) medium by forced hydrolysis of ionic Zn2+ salts. Particle size and shape were controlled by addition of small molecules and macromolecules such as tri-n-octylphosphine oxide, sodium dodecyl sulfate, polyoxyethylene stearyl ether, and bovine serum albumin. Transmission electron microscopy (TEM) and X-ray diffraction analyses were used to characterize particle structure, size, and morphology. Bactericidal tests were performed in Luria-Bertani medium on solid agar plates and in liquid systems with different…