Antibacterial activity of kaolinite/nanoTiO2 composites in relation to irradiation time

Nanostructured composite material graphite/TiO2 and its antibacterial activity under visible light irradiation

“…Pure graphite can be decomposed via effect of produced ROS however in the case of GrafTi composites the defects in the structure of TiO 2 coatings are not significant to decompose the graphite structure. Achieved experimental data are in accordance with our previous experiment [13] which proved that daylight can induce photocatalyticallybased antibacterial activity of TiO 2 containing nanocomposites and thus the use of UV light is not necessary. In comparison with previous work [13] where daylight induced antibacterial activity of kaolinite/nanoTiO 2 (KATI) composites was studied, we can say that the onset of antibacterial activity of the GrafTi composites is faster than KATI, especially against P. aeruginosa, however generally lower MIC values were determined for KATI composites.…”

“…Achieved experimental data are in accordance with our previous experiment [13] which proved that daylight can induce photocatalyticallybased antibacterial activity of TiO 2 containing nanocomposites and thus the use of UV light is not necessary. In comparison with previous work [13] where daylight induced antibacterial activity of kaolinite/nanoTiO 2 (KATI) composites was studied, we can say that the onset of antibacterial activity of the GrafTi composites is faster than KATI, especially against P. aeruginosa, however generally lower MIC values were determined for KATI composites. Therefore, it has to be pointed out that the matrix in nanostructured composite material could play a role in resulting biological activity.…”

“…Before and after irradiation, living cells were transferred from the reaction plate to a plate with pure media and 8 h of irradiation was applied again. This modification of the standard microdilution method eliminated issues with the determination of MIC caused by turbidity of dead cells or caused by the presence of the GrafTi sample particles in microtitration plate, because only living bacterial cells can be captured by needles of the inoculation hedgehog [13]. Due to this fact, the ROS production of TiO 2 was not observed under dark conditions and one study [15] described no antibacterial activity of Degussa P25 under dark conditions parallel experiments under dark conditions were not carried out.…”

“…In this work, graphite was selected as a substrate due to its wide use and environmental safety. Antibacterial activity, cytotoxicity or other form of biological activity of titanium dioxide nanoparticles has been described in many studies [9][10][11][12][13]. These nano-TiO 2 based materials could be potentially used for example for surface modification of different materials to avoid a bacterial contamination.…”

Photodegradation of organic pollutants using N-titanium oxide catalyst

“…Zan et al [18] investigated the photocatalysis effect of nanometer TiO 2 particles and TiO 2 -coated ceramic plate on Hepatitis B virus surface antigen (HBsAg). Dědková et al [19] addresses laboratory preparation and antibacterial activity testing of kaolinite/nanoTiO 2 composite in respect of the daylight irradiation time. Kaolinite/nanoTiO 2 composites with 20 and 40 wt% of TiO 2 were laboratory prepared, dried at 105°C and calcined at 600°C.…”