LAUSR

The development of technology and industry has made available a variety of different nanomaterials. Particularly popular in practical use have been silicon dioxide nanoparticles and titanium and cerium dioxides. However, it is necessary to evaluate the biological activity of nanoparticles from the point of view of toxicology. Despite the active use of nanoparticles of silicon dioxide and dioxides of titanium and cerium, little is known about their toxic effects on living organisms. This work presents a study of three various nanoparticles of silicon dioxide and dioxides of titanium and cerium. For investigations of nanoparticles morphology and their contact with E. coli K12 TG1 cells, suspensions alone or previously mixed with nanoparticles, were applied to freshly prepared mica. To assess the activity of the nanoparticles against E. coli K12 TG1 cells, we used a previously described version of bioluminescent analysis. TiO2 particles having smaller dimensions were characterized by a higher toxicity compared to SiO2. These results characterized TiO2 (I) as toxic and confirm the statement that size matters. Metal particles of CeO2 in the studied concentrations of 0.1–0.000195 M did not cause changes in the dynamics of bacterial bioluminescence. The results were confirmed by studies carried out using lux-biosensors: E. coli K12 MG1655 pkatG'::lux (for the detection of peroxide of hydrogen) and E. coli K12 MG1655 psoxS'::lux ( for the detection of superoxide anion)) for the assessment of oxidative damage.