Phytosynthesis via wasted onion peel extract of samarium oxide/silver core/shell nanoparticles for excellent inhibition of microbes

Abstract

The aqueous onion peel extract (OPE) was used to synthesize silver nanoparticles (Ag-onion), samarium oxide nanoparticles (Sm₂O₃-onion), and silver/samarium oxide core/shell nanoparticles (Ag@Sm₂O₃-onion). The produced nanoparticles were characterized by thermal gravimetric analysis (TGA), infrared spectra (FT-IR), absorption spectra (UV-Vis), energy band gap, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), zeta potential, and transmission electron microscopy (TEM). OPE and NPs were tested for the disinfection of some water microbes. XRD analysis exhibited an amorphous structure of samarium oxide in both Sm₂O₃-onion and Ag@ Sm₂O₃-onion. The isolated bacteria from the water sample were <i>Bacillus subtilis</i> (OQ073500) and <i>Escherichia coli</i> (MW534699), while the isolated fungi were <i>Alternaria brassicae</i> (MZ266540), <i>Aspergillus flavus</i> (MT550030), <i>Aspergillus penicillioides</i> (MW957971), <i>Pythium ultimum</i> (MW830915), <i>Verticillium dahlia</i> (MW830379), <i>Fusarium acuminatum</i> (MZ266538), <i>Candida albicans</i> (MW534712), <i>and Candida parapsilosis</i> (MW960416). High levels of antimicrobial activity were seen in both the nanoparticles and the aqueous onion peel extract. Based on experimental results, Ag@Sm₂O₃ demonstrated the highest activity as an effective disinfectant, indicating the effectiveness of the modification process.