This article reports the green fabrication of cerium oxide nanoparticles (CeO 2 NPs) using Olea europaea leaf extract and their applications as effective antimicrobial agents. O. europaea leaf extract functions as a chelating agent for reduction of cerium nitrate. The resulting CeO 2 NPs exhibit pure single-face cubic structure, which is examined by X-ray diffraction, with a uniform spherical shape and a mean size 24 nm observed through scanning electron microscopy and transmission electron microscopy. Ultraviolet-visible spectroscopy confirms the characteristic absorption peak of CeO 2 NPs at 315 nm. Fourier transform infrared spectroscopy reflects stretching frequencies at 459 cm −1 , showing utilization of natural components for the production of NPs. Thermal gravimetric analysis predicts the successful capping of CeO 2 NPs by bioactive molecules present in the plant extract. The antimicrobial studies show significant zone of inhibition against bacterial and fungal strains. The higher activities shown by the green synthesized NPs than the plant extract lead to the conclusion that they can be effectively used in biomedical application. Furthermore, reduction of cerium salt by plant extract will reduce environmental impact over chemical synthesis.

In this study, we have investigated the effect of copper oxide nanoparticles (CuO-NPs) on callogenesis and regeneration of Oryza sativa L (Super Basmati, Basmati 2000, Basmati 370, and Basmati 385). In this regard, CuO-NPs have been bio-synthesized via Azadirachta indica leaf extract. Scanning electron microscope (SEM) analysis depicts average particle size of 40 ± 5 nm with highly homogenous and spherical morphology. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) have been employed to confirm the phase purity of the synthesized NPs. It is found that CuO-NPs exhibit very promising results against callus induction. It is attributed to the fact that green synthesized CuO-NPs at optimum dosage possess very supportive effects on plant growth parameters. In contrast to callogenesis, differential regeneration pattern has been observed against all of the examined O. sativa L. indigenous verities. Overall observation concludes that CuO, being one of the essential plant nutrients, has greatly tailored the nutritive properties at nano-scale.

In present investigation, copper oxide (CuO) nanostructures have been prepared via green chemistry. leaf extract act as strong chelating agent for tailoring physical as well as bio-medical characteristics of CuO at the nano-size. Physical characterisation such as scanning electron microscope analysis depicts the formation of homogenised spherical shape nanoparticles (NPs) with average size of 42 nm. X-ray diffraction and Fourier transform infrared spectroscopy further confirmed the crystalline pure phase and monoclinic structure. High performance liquid chromatography (HPLC) testing is performed to evaluate the relative concentration of bioactive molecules in the leaf extract. From HPLC results capping action of organic molecules around CuO-NPs is hypothesised. The antimicrobial potency of biosynthesised CuO-NPs have been evaluated using colony forming unit (CFU) counting assay and disc diffusion method which shows a significant zone of inhibition against bacterial and fungal strains may be highly potential for future antimicrobial pharmaceutics. Furthermore, reduction of various precursors by plant extract will reduce environmental impact over chemical synthesis.

To grapple with cancer, implementation of differentially cytotoxic nanomedicines have gained prime attention of the researchers across the globe. Now, ceria (CeO2) at nanoscale has emerged as a cut out therapeutic agent for malignancy treatment. Keeping this in view, we have fabricated SnxCe1-xO2 nanostructures by facile, eco-friendly, and biocompatible hydrothermal method. Structural examinations via XRD and FT-IR spectroscopy have revealed single phase cubic-fluorite morphology while SEM analysis has depicted particle size ranging 30-50nm for pristine and doped nanostructures. UV-Vis spectroscopy investigation explored that Sn doping significantly tuned the band gap (eV) energies of SnxCe1-xO2 nanostructures which set up the base for tremendous cellular reactive oxygen species (ROS) generations involved in cancer cells’ death. To observe cytotoxicity, synthesized nanostructures were found selectively more toxic to neuroblastoma cell lines as compared to HEK-293 healthy cells. This study anticipates that SnxCe1-xO2 nanostructures, in future, might be used as nanomedicine for safer cancer therapy.

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.