Antibacterial response of Cd-TiO2/PEG/folic acid nanocomposite under ultraviolet, visible light, or ultrasonic irradiation

Synthesis and characterization of Cd-TiO2/PEG/FA nanocomposite as a biomaterial is the main aim of this research. Cd-doped TiO2 nanoparticles (NPs) were synthesized by solvothermal assisted sol-gel method. Then, polyethylene glycol (PEG) was added to the as-synthesized NPs in order to modify their surface and to prevent agglomeration. In the next step, folic acid (FA) was conjugated to Cd-TiO2/PEG nanocomposite. Optimization of FA concentration and influence of ultraviolet (UV) radiation, visible light, or ultrasonic irradiation on antibacterial activity of the synthesized nanocomposite were assessed. Results showed that the influence of FA on the antibacterial performance of the as-synthesized compounds is positive and dose-dependent. FA was used as bait for bacteria and led them to accumulate around the Cd-TiO2 NPs. The bactericidal response under UV or visible light irradiation was maximized at 0.6 weight ratio of FA to Cd-TiO2, whereas, this parameter under ultrasonic irradiation was improved and then became approximately constant.