Ag Nanoparticles Connected to the Surface of TiO2 Electrostatically for Antibacterial Photoinactivation Studies

• Published in: Photochemistry and photobiology 2018-11, Vol.94 (6), p.1249-1262
• Main Authors: Deshmukh, Shamkumar P., Mullani, Sajid B., Koli, Valmiki B., Patil, Satish M., Kasabe, Pramod J., Dandge, Padma B., Pawar, Sachin A., Delekar, Sagar D.
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Antimicrobial activity; Bacteria; Catalysts; Chemical reduction; Deactivation; E coli; Energy gap; Inactivation; Irradiation; Light irradiation; Minimum inhibitory concentration; Morphology; Nanocomposites; Nanoparticles; Organic chemistry; Photocatalysis; Photoinactivation; Photoluminescence; Photons; Plates (structural members); Recombination; Silver; Sol-gel processes; Titanium dioxide; Transmission electron microscopy; Ultraviolet radiation
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1111/php.12983

Supported silver nanoparticles (Ag NPs) were prepared by chemical reduction method with a sol‐gel method. The structure, morphology, and interconnectivity of Ag/TiO2 nanocomposites (NCs) were analyzed using different instrumental techniques. Transmission electron microscopy reveals the Ag NPs have uniformly distributed and anchored on the surface of TiO2. The reduction in electron‐hole recombination was measured by Photoluminescence measurements lead, to an increased photocatalytic inactivation of bacteria. Increase in the amount of Ag NPs on TiO2 resulted in a slight decrease in optical band gap energy of TiO2. The effect of Ag NPs content on the photocatalytic properties of TiO2 for inhibition of bacteria in visible light irradiation was studied. Furthermore, the antibacterial activity of Ag/TiO2 NCs in the presence of UVA light was studied against gram‐positive Staphylococcus aureus and gram‐negative Escherichia coli bacterial strain by plate count method. Lower values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the catalysts were observed and used to determine the tolerance factor which is shown bactericidal nature of the NCs. Subsequently, time‐killing assay of Ag/TiO2 NCs was shown dynamics of antimicrobial activity. These multifold antibacterial studies exhibited potent antibacterial nature of the NCs and employed in the wider range of biomedical fields. Herein, Ag/TiO2 NCs were synthesized by facial and ease sol‐gel method which exhibited electrostatic connectivity between Ag with TiO2 nanoparticles. The XPS, FTIR, as well as TEM analysis were confirmed that Ti‐O‐Ag network is formed due to the connectivity of Ag NPs and negatively charged oxygen (Oδ−) of TiO2 in the NCs, which also reveals the strong electrostatic interaction between Ti‐O networks with Ag NPs.