Evaluation of copper(I)-doped zinc oxide composite nanoparticles on both gram-negative and gram-positive bacteria

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2022-06, Vol.643, p.128742, Article 128742
• Main Authors: Kong, Jing, Zhang, Sufen, Shen, Ming, Zhang, Jingui, Yoganathan, Sabesan
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Cu-doped ZnO; Nanoparticles; Photocatalytic; ZnO
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2022.128742

Antibiotic resistance is a serious problem all over the world. Inorganic metal oxide nanoparticles are suitable substitutional treatments for organic antibiotic-resistant bacterial infections. Various copper dopped ZnO nanocomposites were prepared with chemical deposition method in aqueous solution. X-ray diffraction (XRD) coupled with energy dispersive spectroscopy results reveals that cuprous oxide is uniformly doped on the surface of ZnO nanoparticles, forming Cu2O/ZnO nanocomposites. In addition, from Transmission electron microscopy (TEM) and scanning electron microscopy analysis, the average size of prepared Cu2O/ZnO composite is about 30 nm. The antibacterial activity of the Cu2O/ZnO composite was examined on two bacteria strains: Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). When the doping amount of Cu2O reaches more than 5%, a 3.58 log-reduction of S. aureus growth under visible light within 30 mins treatment was observed. The antibacterial activity of Cu2O/ZnO is 2.7-fold higher than pure ZnO and killing bacteria on E. coli with a 1.0 log-reduction in viability. Meanwhile, the bacteriological properties of Cu doped ZnO composites with different valence states (Cu2+, CuO, Cu2O, and Cu0) were compared. Furthermore, the antibacterial mechanism was further discussed in this paper. [Display omitted] •A set of novel Cu2O-doped ZnO nanoparticles were prepared.•Doped nanocomposites can be activated by visible light.•Doped nanoparticles exhibit improved antibacterial activity.•The possible mechanism of action was explored.