Antibacterial and Photocatalytic Activity of ZnO/Au and ZnO/Ag Nanocomposites

• Published in: International journal of molecular sciences 2023-12, Vol.24 (23), p.16939
• Main Authors: Busila, Mariana, Musat, Viorica, Alexandru, Petrica, Romanitan, Cosmin, Brincoveanu, Oana, Tucureanu, Vasilica, Mihalache, Iuliana, Iancu, Alina-Viorica, Dediu, Violeta
• Format: Article
• Language: English
• Subjects: Analysis; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibacterial agents; antimicrobial; Antimicrobial agents; Bacteria; Biocompatibility; Efficiency; Gold; Gold - pharmacology; Investigations; Metal Nanoparticles - chemistry; Metals; Methylene blue; Methylene Blue - chemistry; Nanocomposites; Nanocomposites - chemistry; Nanomaterials; Nanoparticles; Nanostructured materials; Optical properties; Photocatalysis; photocatalytic activity; Photodegradation; Pollutants; Silver; Staphylococcus aureus; Wastewater; Zinc Oxide - chemistry; Zinc Oxide - pharmacology; Zinc oxides; ZnO/Ag; ZnO/Au
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms242316939

The use of a combination of nanoparticles as antimicrobial agents can be one strategy to overcome the tendency of microbes to become resistant to antibiotic action. Also, the optimization of nano-photocatalysts to efficiently remove persistent pollutants from wastewater is a hot topic. In this study, two composites ZnO/Au (1% wt.) and ZnO/Ag (1% wt.) were synthesized by simple aqueous solution methods. The structure and morphology of the r nanocomposites were analyzed by structural and optical characterization methods. The formation of AuNPs and AgNPs in these experiments was also discussed. The antimicrobial properties of ZnO, ZnO/Au, and ZnO/Ag nanomaterials were investigated against Gram-negative bacteria ( ) and Gram-positive bacteria ( ). The results showed an increase of 80% in the antimicrobial activity of ZnO/Au against compared with 30% in the case of ZnO/Ag. Similarly, in the case of the strain tests, ZnO/Au increased the antimicrobial activity by 55% and ZnO/Ag by 33%. The photocatalytic tests indicated an improvement in the photocatalytic degradation of methylene blue (MB) under UV irradiation using ZnO/Au and ZnO/Ag nanocomposites compared to bare ZnO. The photocatalytic degradation efficiency of ZnO after 60 min of UV irradiation was ∼83%, while the addition of AuNPs enhanced the degradation rate to ∼95% (ZP2), and AgNP presence enhanced the efficiency to ∼98%. The introduction of noble metallic nanoparticles into the ZnO matrix proved to be an effective strategy to increase their antimicrobial activity against and , and their photocatalytic activity was evaluated through the degradation of MB dye. Comparing the enhancing effects of Au and Ag, it was found that ZnO/Au was a better antimicrobial agent while ZnO/Ag was a more effective photocatalyst under UV irradiation.