Bio-approach ZnO/Ag nano-flowers: enhanced photocatalytic and photoexcited anti-microbial activities towards pathogenic bacteria. (June 2022)

• Record Type: Journal Article
• Authors: Harinee, S.; Muthukumar, K.; James, R.A.; Arulmozhi, M.; Dahms, H.-U.; Ashok, M.
• Is Part Of: Materials today sustainability. Volume 18(2022)
• Publication Date: 2022-06
• Subjects: Water treatment -- Sargassum muticum -- Nano-flowers ZnO/Ag -- Anti-microbial efficacies -- Dye degradation -- UV-light phototherapy; Materials science -- Environmental aspects -- Periodicals; Sustainable engineering -- Periodicals; 620.11
• DOI: 10.1016/j.mtsust.2022.100133
• Languages: English
• ISSNs: 2589-2347

Abstract

Abstract: Zinc oxide (ZnO) and silver (Ag) nanoparticles (NPs) are well proven as one of the most common anti-microbial agents used for many environmental applications. However, in the present study, Sargassum muticum (SM) -mediated nanoparticles (NPs) and its their nanocomposites (NCs) were proved to be photocatalytic and photoexcited anti-microbial agents. Drug-resistant superbugs (DRS) were isolated, cultured, and 16s rDNA identified as B. filamentosus ; B. flexus ; P. stutzeri ; and A. baumannii . The anti-microbial and photoexcited anti-microbial studied by using various microbes such as pathogenic bacteria (PB), drug-resistant superbugs (DRS), and marine biofilm bacteria (MBB), respectively. The anti-microbial activity showed 80 μg/mL of flower-like SMZnO/Ag–NCs (S5) displayed a maximum growth inhibition of 21 mm against PB and a minimum of 11 mm against DRS. The photoexcited anti-microbial killing efficacy was observed in Gram-positive PB strains showed a maximum activity of 16.7 [ × 10 2 ] and a minimum in DRS 14.6 [ × 10 3 ] CFUs mL −1 and Gram-negative strains 9.4 [ × 10 2 ] and minimum in DRS 10.1 [ × 10 3 ] CFUs mL −1 display a reduced density within 20 min interval. The results indicate, that green NCs with UV-light phototherapy to generating reactive oxygen species (ROS) that cause bacterial cell death. In addition, the UV-light phototherapy combined with nano-flowers S5 attained an effective degradation of harmful toxic methylene blue (MB) dyes up to 98.6% upon 45 min of irradiation. Photostability/reusability of prepared nano-flowers S5 provided up to 6 consecutive cycles of usage towards MB decolorization for the aquatic environment as well as anti-microbial effects. Graphical abstract: Image 1 Highlights: Pathogens and dyes constitute a serious problem for the planet. Sargassum muticum (SM) extracts provide nonhazardous capping/stabilizing agents. SMZnO/Ag–NCs show superior photoexcited anti-bacterial effects. Nano-cure SMZnO/Ag–NCs catalysts are easily recovered and recycled than physical/chemical methods.