Synthesis of Silver‐Doped Titanium Dioxide Nanoparticles by Sol‐Gel and Coprecipitation Techniques: Evaluation of Antimicrobial Activity and Cytotoxic Effects

Abstract

TiO2 nanoparticles are effective alternative to the antibiotics. The quick recombination of the photogenerated charges and the inefficient exploitation of visible light remain the major problems limiting their large‐scale applications. Modifying the TiO2 with Silver that acting as an electron trap, plays an important role in reducing the recombination of TiO2 charges and shift its photo‐response to the visible light region. The present work aims to synthesize AgTiO2 nanoparticles using sol‐gel and coprecipitation methods and evaluating the antimicrobial behavior of them. Also, to find the optimal conditions based on the anatase phase of TiO2 due to its higher antimicrobial activity than the rutile form. Among Ag‐TiO2 nanoparticles obtained, the one prepared by sol‐gel method at 450 °C and PH=8–8.5 exhibits the best antimicrobial property. AgTiO2 nanoparticles have been characterized by means X‐ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR),scanning electron microscope (SEM), ζ‐potential, dynamic light scattering (DLS) that showing promising results. Zeta potential values −103 mV has been reported that is considered as a stable colloidal suspension system that prevents nanoparticles aggregation. Antimicrobial behavior of them were evaluated using Diffusion (Agar disk‐diffusion), Dilution (MIC) and Bacterial colony counting methods and diameter of the inhibitory zone 15 mm and minimum inhibitory concentration 5 mg/ml was observed.Colony count results indicated that AgTiO2 able to kill bacteria at the lowest concentration of 5 mg/ml. Outcomes of MTT assay (measure cell cytoxicity) suggesting the absence of toxicity in living Hfff cells (as a normal human fibroblast) while surviving L929 cells (as a cancer cell line originated from mouse fibroblast cells). After 24 and 48 h incubation from 100 % to 77.3 % and 57.2 % was reduced respectively. This indicates that Ag/TiO2 nanoparticles act as a anticancer drug and have inherent selective toxicity nature towards cancer cells while posing no effect to normal cells. AgTiO2 nanoparticles are synthesized using sol‐gel and coprecipitation methods. The sample prepared by the sol‐gel method at a temperature of 450 °C and pH=8.5, which corresponds to the anatase phase of TiO2 synthesis, shows the best antimicrobial properties and acts as an anticancer drug with inherent selective toxicity nature towards cancer cells while posing no effect on normal cells.