Biosynthesis of Copper Oxide Nanoparticles Using Sargassum wightii and Their Biological Applications

ABSTRACT The primary purpose of this work is the synthesis of copper oxide nanoparticles in an aqueous media utilizing Sargassum wightii whole plant extract. A qualitative screening was conducted to identify secondary metabolites present in the S. wightii extract. The biosynthesized nanoparticles underwent spectral tests (Ultraviolet–Visible [UV‐Vis], Fourier transform infrared [FTIR], x‐ray diffraction [XRD], x‐ray photoelectron spectroscopy [XPS], scanning electron microscopy [SEM], and transmission electron microscopy [TEM]) to characterize them before being screened for larvicidal, antimicrobial, and anticancer properties in vitro. The material was crystalline and exhibited monoclinic phases, which were seen on the XRD graph. The average crystalline size is calculated be 14.19 nm. Spherical morphology is identified from TEM with an average size of 60 nm. The XPS spectra of CuO nanoparticles revealed the oxidation state of Cu as +2. The antibacterial and antifungal activities of SW‐CuO NPs were evaluated against various strains of bacteria ( Bacillus subtilis, Klebsiella pneumoniae, Staphylococcus aureus , and Escherichia coli ) and fungi ( Candida albicans and Aspergillus fumigates ). The result of the antibacterial activity indicated 22 mm zone of inhibition against S. aureus . The results of the fungal activity indicated the 24 mm zone of inhibition against A. fumigates . The cytotoxicity experiments conducted on a liver cancer cell line showed the inhibition of the cell line at 81.68 µg/mL, suggesting the cell lines susceptibility to the HepG2 strain. The exposure to tailored SW‐CuO NPs was favorably linked with the larvicidal activity. The extract mortality rate and the synthesized SW‐CuO NPs mortality rate were recorded after a 12, 24, and 48 h period. This work showed that SW‐CuO NPs are 100% lethal and toxic to Anopheles stephensi (AS) and Aedes aegypti (AE) stages of development in larvae. The results of this work with respect to antimicrobial, larvicidal, and in vitro anticancer screenings offer strong proof that SW‐CuO NPs, which are derived from an aqueous extract of S. wightii , have a wide range of biological applications. These applications can be further investigated by identifying the possible phyto constituents that underlie the activity.