Facile synthesis of copper oxide nanoparticles (CuONPs) using green method to promote photocatalytic and biocidal applications

Synthesis of carboxylated cellulose nanocrystal/ZnO nanohybrids using Oxytenanthera abyssinica cellulose and zinc nitrate hexahydrate for radical scavenging, photocatalytic, and antibacterial activities

The extremely low antioxidant, photocatalytic, and antibacterial properties of cellulose limit its application in the biomedical and environmental sectors. To improve these properties, nanohybrides were prepared by mixing carboxylated cellulose nanocrystals (CCNCs) and zinc nitrate hexahydrate. Data from FTIR, XRD, DLS, and SEM spectra showed that, ZnO nanoparticles, with a size ranging from 94 to 351 nm and the smallest nanoparticle size of 164.18 nm, were loaded onto CCNCs. CCNCs/ZnO1 nanohybrids demonstrated superior antibacterial, photocatalytic, and antioxidant performance. More considerable antibacterial activity was shown with a zone of inhibition ranging from 26.00 ± 1.00 to 40.33 ± 2.08 mm and from 31.66 ± 3.51 to 41.33 ± 1.15 mm against Gram-positive and Gram-negative bacteria, respectively. Regarding photodegradation properties, the maximum value (∼91.52 %) of photocatalytic methylene blue degradation was observed after 75 min exposure to a UV lamp. At a concentration of 125.00 μm/ml of the CCNC/ZnO1 nanohybrids sample, 53.15 ± 1.03 % DPPH scavenging activity was obtained with an IC50 value of 117.66 μm/ml. A facile, cost-effective, one-step synthesis technique was applied to fabricate CCNCs/ZnO nanohybrids at mild temperature using Oxytenanthera abyssinica carboxylated cellulose nanocrystals as biotemplate. The result showed that CCNCs/ZnO nanohybrids possess potential applications in developing advanced functional materials for dye removal and antibacterial and antioxidant applications.

Facile Microwave-Assisted Hydrothermal Synthesis of Copper Oxide Nanoneedle Arrays for Practical Biomedical Applications

INTRODUCTION

Copper oxide nanoneedle arrays (CuO NAs) have been widely used as antibacterial agents and in therapeutic applications because of their unique physicochemical features, low cytotoxicity, low cost, exceptional antibacterial action, and significant interest in biomedicine. Various analytical techniques were used to assess the related phase constitution, optical characteristics, elemental content, and surface morphology. The X-ray diffraction (XRD) patterns and field-emission scanning electron microscopy (FE-SEM) micrographs revealed that the CuO NAs had a monoclinic phase with a nanoneedle-like shape. Our findings may cover the progress of innovative and effective anti-bacterial capabilities based on CuO NAs, which have been shown to be effective against various pathogens, making them ideal options for fighting bacterial infections.  Objective: This research aimed to synthesize CuO NAs using microwave-solvothermal (MW-ST) technology, explore their effectiveness, and assess their biological activity.

METHODS

The CuO NAs were synthesized using the MW-ST process, and their properties were assessed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive analysis (EDS), field emission transmission microscopy (FE-TEM), and ultraviolet-visible (UV-Vis) techniques. The biocompatibility of CuO NAs was determined through hemolytic assays, and their bioactivities like antioxidant and anti-inflammatory assays were also determined.

RESULTS

The CuO NAs were successfully developed, and various analytical tools were used to characterize and validate their morphology, size, crystallinity, and elemental compositions. It has been shown in in-vitro investigations that a strong anti-inflammatory impact is demonstrated by the inhibition of protein denaturation with low hemolytic potential. As a result, CuO NAs have the potential to be an excellent choice for anti-inflammatory solicitations.

CONCLUSION

CuO NAs were synthesized and characterized with various advanced techniques, revealing the formation of nanoneedles-like morphology. Based on the experimental findings, CuO NAs have the potential for anti-microbial, anti-oxidant, anti-inflammatory, and anti-hemolytic activities. However, additional in-vivo testing is essential to properly evaluate their efficiency and safety.

Synthesis of CuOx nanostructures in novel electrolytes under hydrodynamic conditions for photoelectrochemical applications

In this work, CuOx (x = 1 and 2) nanostructures have been synthesized by electrochemical anodization in ethylene glycol based electrolytes using oxalic acid or NaF (with or without NaOH) as complexing agents. The influence of hydrodynamic conditions and time during anodization of copper have also been evaluated. A comprehensive morphological, structural, electrochemical and photoelectrochemical characterization of the nanostructures has been performed. The results revealed the convenient use of oxalic acid and 250 rpm for 5 minutes during electrochemical anodization to obtain homogeneous CuOx nanostructures formed by spheres with Cu2O as a predominant phase. Using this nanostructure as a photocathode for N2O photoelectron-reduction, almost 100% of N2O removal was achieved after 1 h, showing the improvement of the photoelectrochemical approach vs. the photo or the electro performance.

Biosynthesis of silver nanoparticles using tea leaf extract (camellia sinensis) for photocatalyst and antibacterial effect

Silver nanoparticles (C. AgNPs) are synthesized by the biological reduction method using extracts from green tea leaves (Camellia Sinensis) collected from tea hills at an altitude of 100 m above the ground. The chemicals present in the tea leaf extract act as reducing agents used to reduce Ag+ ions to silver atoms to form C. AgNPs in the solution. In this work, we optimized the C. AgNPs synthesis process by investigating the influence of reaction parameters such as concentration of tea leaf extract (1 ppm-50 ppm), reaction temperature (30 °C-60 °C), reaction time (5 min-100 min), and reaction rate (400 rpm-800 rpm) through absorption UV-Vis spectroscopy, TEM transmission electron microscopy, and spectroscopy X-ray. Organic compounds in tea leaf extract are detected by NMR measurement. The functional groups on the C. AgNPs are shown on the Fourier transform infrared (FTIR) spectrum. The C. AgNPs are used to degrade MB dye at 10 ppm concentration based on the photocatalytic effect using a 6500 K white light source. The C. AgNPs have also been studied for their antibacterial activity on two bacteria, Pseudomonas aeruginosa (P.A) and Staphylococcus aureus (S.A), while a positive control is Ampicillin 50 mg/ml and a negative control is H2O. The results reveal that the C. AgNPs with diameters in the range of 25 nm-55 nm degrade 10 ppm MB dye after 1 h with photodegradation efficiency up to 96 %. The antibacterial ability of C. AgNPs against both bacteria is good, even superior to that of Ampicillin. Furthermore, the particle synthesis efficiency and therefore the antibacterial activity as well as the photodegradation effect of C. AgNPs are higher than previously reported. At the same time, using green tea leaf extract to synthesize C. AgNPs creates environmentally friendly products. These useful behaviors are the potential to increase the scope and applicability of C. AgNPs, especially for biomedical applications in the near future.

Investigation of structural, morphological, optical, elemental, and anticancer property of pure ZnO and PbO: ZnO nanocomposites prepared by flame synthesis method

In this work, Pure ZnO nanoparticles and a nanocomposite of PbO: ZnO were prepared by the flame synthesis method, and was analyzed for structural, morphological, optical, elemental, and biocompatibility studies. The structural analysis revealed a hexagonal structure for ZnO and an Orthorhombic structure for PbO: ZnO nanocomposite. Scanning electron microscopy (SEM) image showed a Nano-Sponge-like surface morphology for PbO: ZnO nanocomposite and energy dispersive spectra (EDS) confirmed the absence of undesired impurities. Transmission electron microscopy (TEM) image showed a particle size of ∼50 nm for ZnO and ∼20 nm for PbO: ZnO. Using Tauc plot the optical band gap was found to be 3.2 eV for ZnO and 2.9 eV for PbO: ZnO. Anticancer studies confirm the excellent cytotoxicity activity of both compounds. PbO: ZnO nanocomposite has demonstrated the highest cytotoxicity against the tumorigenic HEK 293 cell line with the lowest IC₅₀ value of 13.04 μM. Our study shows that the prepared PbO: ZnO nanocomposite has a huge potential in cancer therapy.

Biogenic synthesis, molecular docking, biomedical and environmental applications of multifunctional CuO nanoparticles mediated Phragmites australis

The demand for metal nanoparticles is increasing with the widening application areas while causing environmental impact including pollution, toxic byproduct generation and depletion of natural resources. Incorporating natural materials in nanoparticle synthesis can contribute toward environmental sustainability. This paper is concerned with the biogenic synthesis of copper oxide nanoparticles (CuONPs) mediated by the plant species Phragmites australis. UV-vis, FT-IR, TEM and SEM studies were used to characterize the obtained CuONPs. The synthesized nanoparticles' antibacterial efficacy against Escherichia coli and Staphylococcus aureus was assessed. The CuONPs' reducing power, total phenolic component content, and flavonoid content were all calculated. Additionally, the dye removal abilities of copper oxide nanoparticles using Brilliant Blue R-250 were studied. The CuONP synthesis was assessed morphological by change of color and in the UV-vis analysis by the SPR band around 320 and 360 nm. FT-IR was used to monitor the functional groups present in the synthesized CuONPs. The obtained CuONPs were spherical and between 70 and 142 nm in size, according to the SEM data and TEM analyses were in accordance with SEM results. Using disk diffusion, the CuONPs demonstrated substantial antibacterial efficacy against S. aureus and E. coli, with inhibition zones of 18.5 ± 0.8 and 12.7 ± 0.6 mm, respectively. The MBC and MIC values were 62.5 μg/mL against S. aureus and 125 μg/mL against E. coli. The antioxidant abilities of P. australis and CuONPs were also confirmed. The CuONP solution's total phenolic substance content was 9.44 μg of pyrocathecol equivalent per milligram of nanoparticle, and its total flavonoid content was 16.24 μg of catechin equivalent per milligram of nanoparticle. Additionally, the synthesized CuONPs were found to be well effective on industrial dye removal by demonstrating high decolorization of 98 %. Also, the antibacterial activity of CuONPs was investigated through the interactions with S. aureus FtsZ, dihydropteroate synthase and thymidylate kinase. In silico molecular docking analysis was applied in the confirmation of the binding sites and interactions of active sites. CuONP showed -9.067, -8,048, and -7.349 kcal/mol of binding energies in molecular docking analysis of FtsZ, dihydropteroate synthase and thymidylate kinase proteins respectively. The results of this study suggested the antimicrobial, antioxidant and decolorative effect of synthesized CuONPs that can be apply in multiple areas of R&D and industry.

Effect of the green synthesis of CuO plate-like nanoparticles on their photodegradation and antibacterial activities

Green synthesis of copper oxide nanoparticles and its effects on photocatalytic dye degradation and antibacterial activities are reported. The synthesis of nanoparticles by green routes provides many advantages over chemical routes, including simplicity, cost-effectiveness, and fast processing route without using any costly or harmful chemicals. Tridax procumbense (coat buttons) plant root extract was used to synthesize copper oxide nanoparticles. The synthesized Tridax procumbense-copper oxide nanoparticles (TP-CuO NPs) were characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering spectroscopy (DLS), and X-ray diffraction (XRD) techniques. The synthesized TP-CuO NPs were applied for photocatalytic dye degradation and antibacterial activity studies. The TP-CuO NPs exhibited a maximum antibacterial activity at 500 μg mL^-1 concentration against Staphylococcus aureus and E. coli showing inhibition zones of 7.5 mm and 7.2 mm, respectively. The photocatalytic ability of the TP-CuO was also tested against the textile dye Trypan blue (TB), and showed about 55% degradation after 48 h for 500 μg mL^-1 CuO NP concentration, showing a concentration-dependent degradation efficiency. This is the first work on TP-derived CuO nanoparticles and their photocatalytic and antimicrobial applications. Overall, this study supports the superiority of green-synthesized TP-CuO NPs as photocatalytic and antimicrobial agents.

Traditional Uses, Phytochemical Composition, Pharmacological Properties, and the Biodiscovery Potential of the Genus Cirsium

Medicinal plants are rich in phytochemicals, which have been used as a source of raw material in medicine since ancient times. Presently they are mostly used to treat Henoch–Schonlein purpura, hemoptysis, and bleeding. The manuscript covers the classification, traditional applications, phytochemistry, pharmacology, herbal formulations, and patents of Cirsium. The main goal of this review is to impart recent information to facilitate future comprehensive research and use of Cirsium for the development of therapeutics. We investigated numerous databases PubMed, Google Scholar, Springer, Elsevier, Taylor and Francis imprints, and books on ethnopharmacology. The plants of the genus Cirsium of the family Asteraceae contain 350 species across the world. Phytochemical investigations showed that it contains flavonoids, phenols, polyacetylenes, and triterpenoids. The biological potential of this plant is contributed by these secondary metabolites. Cirsium plants are an excellent and harmless agent for the cure of liver diseases; therefore, they might be a good clinical option for the development of therapeutics for hepatic infections. The phytochemical studies of different Cirsium species and their renowned pharmacological activities could be exploited for pharmaceutic product development. Furthermore, studies are required on less known Cirsium species, particularly on the elucidation of the mode of action of their activities.