In the last few years, copper and copper oxide nanoparticles were involved in many applications; this encouraged many researchers worldwide to develop more facile synthesis methods. Unprecedentedly, the current study reports a green method for synthesizing copper/copper oxide nanoparticles (Cu/Cu 2 O NPs) using the extract of seedless dates. Cu/Cu 2 O NPs were synthesized according to the chemical reduction method using seedless dates' extract as a reducing agent due to its high content of phenolics and flavonoids. Transmission Electron Microscopy (TEM) revealed that roughly spherical particles were synthesized. Dynamic Light Scattering (DLS) showed that the synthesized Cu/Cu 2 O NPs have an average particle size of 78 nm and zeta potential of þ41 mV, indicating a good stability of the particles. Successful synthesis of Cu/Cu 2 O NPs was affirmed through both X-Ray Diffraction (XRD), which revealed the presence of the characteristic peaks of copper at 2θ ¼ 43.2745, 50.4083 and 74.1706 , and UV-Vis. Spectroscopy, which revealed the surface plasmonic resonance peak characterizes Cu/Cu 2 O NPs at 576 nm. In addition, Fourier Transform Infrared Spectroscopy (FTIR) revealed the presence of phenolic compounds, which were responsible for reducing copper ions into copper nanoparticles through their carbonyl and hydroxyl linkages, adsorbed from the extract on Cu/Cu 2 O NPs. Conclusively, the current work provides, for the first time, a simple, cost-effective and environmentally friendly method for synthesizing Cu/Cu 2 O NPs using useless seedless dates.

Although many papers have consented that the smaller the size of nanoparticles, the higher their efficiency, this paper sheds light on one potential exception of this rule. The paper shows that the in vitro antifungal efficiency of copper nanoparticles against the fusarium wilt pathogen, Fusarium oxysporum, isolated from the infected date palm, Phoenix dactylifera L., is not size-dependent; instead, as it was found that larger copper nanoparticles have better in vitro antifungal efficiency against the fungal pathogen than smaller ones. Copper nanoparticles were synthesized via chemical reduction method at two different pH values, 6.5 and 10.5. Dynamic light scattering was used to measure their particle sizes, which were 345.1 nm and 278.1 nm, respectively. Transmission Electron Microscopy was used to figure out the shapes of nanoparticles, which were polygonal and spherical, respectively. Poison food essay was used to test their in vitro inhibition efficiencies against the fusarium wilt pathogen, F. oxysporum, isolated from the infected date palm, Phoenix dactylifera L., which were 46% and 19%, respectively; at the same concentration. Ultimately, the paper has proposed and discussed a potential reason beyond these unexpected findings, which relies upon the larger surface area to volume ratio of the polygonal copper nanoparticles compared to the spherical copper nanoparticles. The paper concluded that, despite their larger size, polygonal copper nanoparticles have better in vitro antifungal efficiency than spherical copper nanoparticles against F. oxysporum isolated from the infected date palm, Phoenix dactylifera L. at the same concentration.

Date palm, Phoenix dactylifera, as one of the most important fruit crops in Egypt and many other countries, can be affected by many fungal diseases, among which the vascular wilt disease, caused by the fungal pathogen Fusarium oxysporum, is considered the most deteriorating one. This study aims at evaluating the efficiency of Copper-Chitosan Nanopcomposition for treating the vascular wilt disease in date palm. The study relies mainly on beleaguering the disease via the doublerole functionality of copper-chitosan nanocomposition, i.e. its potential antifungal effect on the fungal pathogen, besides its capability to enhance the immune responses of the infected plant. In this regard, chitosan nanoparticles were prepared according to the ionic gelation method, whereas copper nanoparticles were prepared according to the chemical reduction method. Physicochemical characterization of both chitosan and copper nanoparticles was performed using dynamic light scattering (DLS), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD).Copper-chitosan nanocomposition could significantly reduce the vascular wilt disease severity; this means that the nanocomposition can be used in the future for developing new nanofungicides to control such pathogens.

No abstract