Biogenic synthesis of zinc oxide nanoparticles using Drynaria Quercifolia tuber extract for antioxidant, antibiofilm, larvicidal, and photocatalytic applications

The rapid spread of the drug-resistance among microbes has made the treatment of infections a problematic task. Microbial biofilms are complex aggregations of microbial cells encapsulated in a polymeric matrix that further worsens the treatment of microbial infections. In this study, ZnONPs were synthesized via green route using the aqueous tuber extract of Drynaria quercifolia. Biophysical property of ZnONPs was characterized by UV-vis spectroscopy, XRD, FTIR, SEM with EDS, and HR-TEM analyses and was found to have a size of 10 nm. Synthesized ZnNOPs demonstrated good antimicrobial activity against bacterial (B. cereus, S. typhi, and E. coli) and fungal (A. flavus and C. albicans) strains. Subsequently, the ZnONPs also exhibited excellent antioxidant property DPPH (78.52%), ABTS assay (70.18%), and hydroxyl scavenging assay (77.34%) at 100 mu g/ml concentration. The biofilm inhibitory activity against E. coli, B. cereus, and S. typhi was recorded. Additionally, we also evaluated the larvicidal activity of ZnONPs against Cx. quinquefasciatus and recorded LC50 value of 130.725 mu g/ml. Histopathology studies revealed that the region of hind and mid intestine, epithelial cells, and cortex were affected severely upon the treatment with ZnONPs. Photocatalytic activity was tested on crystal violet for dye degradation. Nearly complete degradation of the tested dye occurred within 72 min. The study suggests that green-synthesized ZnONPs could be a preferred alternative for various biomedical applications and contribute to the eventual elimination of environmental pollutants in the near future.