Papaya (Carica papaya) leaves extract based synthesis, characterizations and antimicrobial activities of CeO2 nanoparticles (CeO2 NPs)

Abstract

The synthesis of CeO2 nanoparticles (CeO2 NPs) using Papaya (Carica papaya) leaves extract was demonstrated in this study. The main components of Carica papaya leaves extracts were investigated through different phytochemical tests. These tests have been indicated the presence of alkaloids, flavonoids, phytosterols, terpenoids, glycosides, and saponins in the extract. These secondary metabolites assist in the capping, stabilization, and reduction of metal oxide-based nanoparticles. Different analytical techniques were used to characterize CeO2 NPs. Fourier transform infrared (FTIR) spectroscopy revealed the presence of O-H, C = O, C-O, Ce-O, Ce-C, etc. on the surface of green synthesized CeO2 NPs. The antibacterial and antifungal activities of biologically synthesized CeO2 NPs were investigated using well diffusion method. For Streptococcus mutans, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Aspergillus fumigatus, and Aspergillus niger, the zones of inhibition around the CeO2 NPs were 34, 28, 38, 44, 36, and 34 mm, respectively.