The Ag Influence on the Surface States of TiO2, Optical Activity and Its Cytotoxicity

Authors M.M. Zahornyi1 , N.I. Tyschenko1 , T.F. Lobunets1, O.F. Kolomys2, V.V. Strelchuk2 , K.S. Naumenko3, L.O. Biliavska3, S.D. Zahorodnia3, O.M. Lavrynenko1 , A.I. Ievtushenko1

1I. Frantsevich Institute for Problems in Material Science, NAS of Ukraine, 3, Krzhizhanovsky St., 03142 Kyiv, Ukraine

2V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 45, Nauky Prosp., 03028, Kyiv, Ukraine

3D. Zabolotny Institute of Microbiology and Virology, NAS of Ukraine, 154, Acad. Zabolotny St., 03143 Kyiv, Ukraine

Issue Volume 13, Year 2021, Number 6
Dates Received 06 October 2021; revised manuscript received 04 December 2021; published online 20 December 2021
Citation M.M. Zahornyi, N.I. Tyschenko, T.F. Lobunets, et al., J. Nano- Electron. Phys. 13 No 6, 06009 (2021)
PACS Number(s) 32.30.Rj, 33.20.Lg, 42.62.Fi, 61.46. – W, 77.22. – d
Keywords Ag/TiO2, Irradiation (10) , Raman (37) , Defects (12) , Optical activity, Cytotoxicity, MTT.

Ag/TiO2 nanoparticles (NPs) were prepared by a simple chemical deposition method using silver nitrate and suspension of TiO(OH)2. Silver NPs were deposited on the surface and inside of TiO2 NPs depended on the Ag concentration. The Ag/TiO2 composites were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy. The cell viability was assessed using an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after NPs exposure, since only viable cells have functional mitochondrial dehydrogenase enzymes that can reduce MTT to formazan. The shift of the Eg mode from 143 to 150 cm – 1 and FWHM from 12 to 19 cm – 1 was stated due to a decrease in TiO2 crystallites. Optical activity increased after loading with Ag because metal particles offered electron traps to reduce recombination of holes and electrons, especially Ag loading of 8 wt. %. A Schottky barrier is formed in the Ag-TiO2 contact region, which improves charge separation and thus slows down the recombination of photogenerated electrons and photogenerated holes. The obtained results indicate a lower toxicity of NPs in a glycerin + water suspension, regardless of the introduction of silver molecules in an amount of 4 or 8 wt. %, their CC50 values were 50 and 3.9-58.5 (g/ml for MDBK and MDCK cells, respectively. The obtained Ag/TiO2 NPs due to their optical activity will be examined as an antifungal material for the inhibition of bacteria and viruses in water.

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