pH dependent synthesis of TiO2 nanoparticles exerts its effect on bacterial growth inhibition and osteoblasts proliferation

Abstract

In the current investigation, titanium-dioxide nanoparticles (TiO2-NPs) are prepared through a sol–gel method at varying pH values of 6, 8, and 10. The effects of pH on the preparation of TiO2-NPs and their structural, morphological, and compositional variations were extensively studied by P-XRD, TEM, FE-SEM, and EDS techniques. The calculated optical bandgap (Eg) was in the range of 3.40 eV to 3.15 eV, with an increase in pH, and was observed by the K–M method. The photocatalytic activity of TiO2-NPs is evident from that the degradation of the reactive black 5 (RB5) dye shows 96% photocatalytic activity at 45 min under UV irradiation. The photocatalytic activity of TiO2-NPs is pH-sensitive. The photocatalytic activity of TiO2-NPs increases if the reaction is performed under acidic conditions. Moreover, all the synthesized TiO2-NPs obey pseudo-first-order kinetics. TiO2-NPs could be coated on medical implants to prevent the growth of micro-organisms and facilitate vascular protection. In this context, 100 µg/ml, 200 µg/ml, and 300 μg/ml of TiO2-NPs were coated on materials as a treatment to study the incorporation of bacteria by flow cytometry analysis. Among the treatments, a statistical increase in E. coli and B. subtilis cell incorporation by around 17.3% and 24% was observed in the groups treated with 200 μg/ml of TiO2-NPs synthesized at pH 6. Furthermore, the cytotoxicity of TiO2-NPs on the osteoblasts cell line, C3H10T1/2, was analyzed for cell viability and proliferation by MTT and BrdU assays, respectively. TiO2-NPs were synthesized at different pH values and a high percentage viability is seen in the samples synthesized at a pH of 6.