ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Green synthesis and first-principles calculations of a highly efficient antibacterial agent: CuO/Ag nanocomposites

Yadullah Baqir, Muhammad Tariq Tunio, Syed Zafar Ilyas, Simeon Agathopoulos, Hareem Mufti, Abdul Jalil, and Ather Hassan

Department of Agriculture, Allama Iqbal Open University, Islamabad, Pakistan

E-mail: ather.hassan@aiou.edu.pk

Received: 16 September 2022  Accepted: 17 December 2022

Abstract:

The current study addresses the problem of diseases transmitted from milk and dairy products to humans by bacteria. In the present study, CuO/Ag nanocomposites were synthesized, characterized, and tested for antibacterial activity. Sharp peaks at 2θ 37.38°, 44.04°, 64.31° and 77.27°, 32.29°, 38.28° and 46.36°, and 44.19°, 64.61° and 77.62° were observed in X-ray diffraction analysis, which correspond to the crystal planes of Ag, CuO and Ag–Cu, respectively. Scanning electron microscope image revealed the spherical shape of CuO/Ag nanopowders, with a size of 70 nm and crystallite size of 32 nm. The ultraviolet spectroscopy gave 2.25 and 2.06 eV bandgap energies for CuO and CuO/Ag, respectively. Furthermore, DFT calculations were performed in support of the experiment, and the structural change charge analysis and electronic band structures were analyzed. The antibacterial activity of CuO/Ag nanocomposites against Escherichia coli and Staphylococcus aureus was also evaluated using the Kirby–Bauer disk diffusion assay. Good antibacterial activity was observed against both milk bacteria with a sensitivity of 40–90% at CuO/Ag concentrations ranging from 6 to 200 mg/100 ml.

Keywords: Green synthesis; Characterization; Antimicrobial activity; Silver–copper nanocomposites; Raw milk

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02637-8

Chemical Papers 77 (5) 2459–2467 (2023)