Visible light photo-induced antibacterial activity of TiO2-MWCNTs nanocomposites with varying the contents of MWCNTs

Abstract

Abstract Nanocrystalline TiO 2 and MWCNTs are important functional materials that have received considerable research interest in the last few decade. In this work, the composites of TiO 2 nanoparticles with varying amount of functionalized MWCNTs were prepared by using a solution-based method. The physico-chemical properties of these composites were studied in connection with their antibacterial activity. TiO 2 particles have non-spherical shape with size in the range of 8–15 nm; which were confirmed through TEM analysis and these particles were well hosted on the surface of MWCNTs. The tuning of optical band gap of nanocomposites was studied by using DR UV-visible spectroscopy. The photocatalytic inactivation of Escherichia coli and Staphylococcus aureus using TiO 2 -MWCNTs nanocomposites in the presence of visible light (λ > 420 nm) has been carried out. These nanocomposites show efficient antibacterial activity under visible light illumination, whereas bare TiO 2 nanoparticles did not show any inhibitory effect on bacteria under visible light exposure. These results suggest that UV light or TiO 2 alone is not effective for photocatalytic disinfection applications. Also, cytotoxicity study reveals that the nanocomposites show better cell viability than bare TiO 2 nanoparticles. Overall, the experimental results suggest that TiO 2 -MWCNTs nanocomposites have been developed as efficient antibacterial agents against a wide range of microorganisms to prevent and control the persistence and spreading of bacterial infections.