Enhanced Antibacterial Activity of Mechanosynthesized Biocompatible Cu‐Ag‐TiO ₂ Nanocomposite

ABSTRACT The Cu‐Ag‐TiO 2 nanocomposite is synthesized by a facile and straightforward mechanical alloying route. The structure and microstructure of the nanocomposite are characterized by analyzing its XRD patterns, FTIR spectra, FESEM, and TEM images. The agar cup diffusion method and minimum inhibitory concentration (MIC) study revealed that the Cu‐Ag‐TiO 2 nanocomposite exhibits enhanced antibacterial activity compared to a common pristine antibiotic, LineZolid 600, and the TiO 2 ‐Ag nanocomposite. The antibacterial activity is further confirmed by measuring total protein leakage and conductivity change in the culture filtrate of Bacillus subtilis treated with the nanocomposite. The diameter of the zone of inhibition after the application of Cu‐Ag‐TiO 2 nanocomposite is about 3.5 cm, where it is 2.2 and 2.8 cm for the application of TiO 2 ‐Ag nanocomposite and antibacterial drug, respectively. The MIC of the TiO 2 ‐Ag sample is 80 µg/mL, and it is 20 µg/mL in the case of the Cu‐Ag TiO 2 sample against the growth of Staphylococcus sp. The cytocompatibility of the nanocomposite verified on the human embryonic kidney (HEK293) cells demonstrates the nontoxicity of the nanocomposite. Thus, we propose a new simple, cost‐effective, and facile route to synthesize a novel biocompatible nanocomposite with significant antibacterial activity.