Antibacterial effect of TiO2 modified with poly-amidoamine dendrimer – G3 on S. aureus and E. coli in aqueous solutions

This study investigated bacterial removal using TiO2 nanoparticles (NPs) modified with poly-amidoamine dendrimer macromolecule (PAMAM, G3). The PAMAM G3/TiO2 (nanohybrid) was used to specify antibacterial properties via broth microdilution (MBC-Minimum Bactericidal Concentration and MIC-Minimum Inhibitory Concentration-determination), paper disc diffusion, and surface plate count methods. The nanohybrid was characterized via the different techniques. The effects of different factors including initial bacteria count, run time, solution pH, and the nanohybrid concentration were studied. The nanohybrid cytotoxicity was studied on AGS and MKN45 cells line by MTT assay. It was revealed that the nanohybrid was effective in intercepting both bacterial strains growth. The MIC value for S. aureus and E. coli were determined to be 4 and 2 μg/mL, respectively. The MBC value for both strains were calculated to be 32 μg/mL. The results showed removal efficiency of 100% for S. aureus and E. coli bacteria in optimum situation. The decrease in cell viability in the dosage of 32 μg/mL after 72 h treatment for AGS and MKN45 cells line were shown to be 6.2 and 4.6%, respectively. The nanohybrid was able to decrease the S. aureus and E. coli count in solution, which meets the drinking water criterions aligned with WHO guidelines. HIGHLIGHTS A novel poly (amidoamine) generation 3-functionalized TiO2 nanoparticle was prepared.; The antibacterial activity was displayed with particles of a nano size which exhibited a distinct homogenous morphology.; Super high removal efficiency was achevied for bacteria in aqueous solution: E. coli and S. aureus.; FE-SEM analysis revealed morphological variations and the mechanism of killing and trapping the bacteria by nanocomposite.; In the MIC and MBC values range, the cytotoxicity effect of nanocomposite on AGS cell line was relatively lower.;