RETRACTED: CuO and CeO2 Nanostructures Green Synthesized Using Olive Leaf Extract Inhibits the Growth of Highly Virulent Multidrug Resistant Bacteria

Abstract

One of the major challenges of nano-biotechnology is to engineer potent antimicrobial nanostructures (NS) with high biocompatibility. Keeping this in view, we have performed aqueous olive leaf extract mediated one pot facile synthesis of CuO-NS and CeO2-NS. Prepared NS were homogenous, less than 26 nm in size, and small crystallite units as revealed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. Fourier transform infrared spectroscopy (FTIR) of CuO-NS and CeO2-NS showed typical Cu-O prints around 592–660 cm-1 and Ce-O bond vibrations at 453 cm-1. The successful capping of CuO-NS and CeO2-NS by compounds present in the plant extract was further validated by high performance liquid chromatography (HPLC) and thermal gravimetric analysis (TGA). Active phyto-chemicals from the leaf extract simultaneously acted as strong reducing as well as capping agent in the NS synthesis. NS engineered in the present study showed antibacterial potential at extremely low concentration against highly virulent multidrug-resistant (MDR) gram-negative strains (Escherichia coli, Enterobacter cloacae, Acinetobacter baumannii and Pseudomonas aeruginosa), alarmed by World Health Organization (WHO). Furthermore, CuO-NS and CeO2-NS did not show any cytotoxicity on HEK-293 cell lines and Brine shrimp larvae indicating that the NS green synthesized in the present study are biocompatible.

<p>Green Synthesis of Cerium Oxide Nanoparticles (CeO₂ NPs) and Their Antimicrobial Applications: A Review</p>

“…Plants in this regard have been the most efficient source due to their abundance, safe nature, and rich source of reducing and stabilizing agents. 26,29 Various parts of plants such as leaves, flower, and stem have been used for the synthesis of CeO 2 NPs. 16,30,31 Till date the majority of green synthesis studies have been conducted on leaves extracts, as it is a rich source of metabolites.…”

“…55,56 Thus, in quest of a new treatment, biogenic CeO 2 NPs has shown promising results in treating multidrug resistance bacteria and could be a promising candidate against such refractory pathogenesis. 26 CeO 2 NPs along other conjugates have been amalgamated with various organic and inorganic hybrids to enhance the antimicrobial response. 17,46 Similarly, bio-mediated CeO 2 NPs kills fungi by producing a mass number of free radicals and ROS which causes distorted structure and physiology and leads to fungus death.…”

Biosynthesis of Copper Oxide Nanoparticles by Marine Streptomyces MHM38 and their Preventive Efficacy Against Paracetamol-Inducing Hepatic Damage of Albino Rats

“…MHM38 (Fig.10), which con rmed the presence of elemental copper by the signals. In the EDX spectrum, the nanoparticles displayed a peak at 8 keV, which is due to the absorption of copper oxide nano crystallites corresponding to surface plasmon resonance (Maqbool et al, 2018). The optical absorption band peak for nanoparticles produced by Streptomyces sp.…”

Preparation of CeO2 Loaded Chitosan-Based Nanofibrous Membranes for Antibacterial Applications

“…Gomez et al [21] synthesized Ce 3+ rich CeO2 nanoparticles, which showed good antibacterial activities against both Gram-negative and Gram-positive bacteria due to the existing Ce 3+ on surface and rich oxygen vacancies in CeO2 nanoparticles. Although there are some reports about the antibacterial activity of CeO2, researchers are mainly focused on the influence of CeO2 to the antibacterial activity of Ag/CeO2, [22] ZnO/CeO2 [23,24] and CuO/CeO2 [25] hybrid nanomaterials. The investigation about the influence of particle size to the antibacterial activity of CeO2 is relatively rare.…”