Comparative green synthesis of zinc oxide nanoparticles using millet extracts and their physicochemical characterization and in vitro antidiabetic activity.

In this work, we present an ecofriendly, non-hazardous, green synthesis of zinc oxide nanoparticles (ZnO NPs) by leaf extract of Crotalaria verrucosa (C. verrucosa). Total phenolic content, total flavonoid and total protein contents of C. verrucosa were determined. Further, synthesized ZnO NPs was characterized by UV–visible spectroscopy (UV-vis), X-ray diffractometer (XRD), Fourier transform infra-red (FTIR) Spectra, transmission electron microscope (TEM), and Dynamic light scattering (DLS) analysis. UV-vis shows peak at 375 nm which is unique to ZnO NPs. XRD analysis demonstrates the hexagonal phase structures of ZnO NPs. FTIR spectra demonstrates the molecules and bondings associated with the synthesized ZnO NPs and assures the role of phytochemical compounds of C. verrucosa in reduction and capping of ZnO NPs. TEM image exhibits that the prepared ZnO NPs is hexagonal shaped and in size ranged between 16 to 38 nm which is confirmed by DLS. Thermo-gravimetric analysis (TGA) was performed to determine the thermal stability of biosynthesized nanoparticles during calcination. The prepared ZnO NPs showed significant antibacterial potentiality against Gram-positive (S. aureus) and Gram-negative (Proteus vulgaris, Klebsiella pneumoniae, and Escherichia coli) pathogenic bacteria and SEM image shows the generalized mechanism of action in bacterial cell after NPs internalization. In addition, NPs are also found to be effective against the studied cancer cell lines for which cytotoxicity was assessed using MTT assay and results demonstrate highest growth of inhibition at the concentration of 100 µg/mL with IC50 value at 7.07 µg/mL for HeLa and 6.30 µg/mL for DU145 cell lines, in contrast to positive control (C. verrucosa leaf extract) with IC50 of 22.30 µg/mL on HeLa cells and 15.72 µg/mL on DU145 cells. Also, DAPI staining was performed in order to determine the effect on nuclear material due to ZnO NPs treatment in the studied cell lines taking leaf extract as positive control and untreated negative control for comparison. Cell migration assay was evaluated to determine the direct influence of NPs on metastasis that is potential suppression capacity of NPs to tumor cell migration. Outcome of the synthesized ZnO NPs using C. verrucosa shows antimicrobial activity against studied microbes, also cytotoxicity, apoptotic mediated DNA damage and antiproliferative potentiality in the studied carcinoma cells and hence, can be further used in biomedical, pharmaceutical and food processing industries as an effective antimicrobial and anti-cancerous agent.

Zinc oxide nanoparticles (ZnO-NPs) have been extensively researched for their potential applications in various fields such as pharmaceuticals, cosmetics, biotechnology, sensing, photocatalysis, and photovoltaics due to their unique nanoscale properties. However, the conventional methods for producing ZnO NPs require the use of hazardous chemicals and high energy consumption, which imposes certain limitations. In contrast, the green synthesis of ZnO-NPs using plant extracts, especially Origanum majorana, has gained much attention as a promising alternative approach. Plant extracts contain phytochemicals that are biologically safe and non-toxic, making them a preferred choice. In addition, the ZnO-NPs synthesized with O. majorana extracts exhibit higher stability and can be customized in terms of shape and size, unlike the ZnO-NPs obtained by bacterial or fungal methods. The aqueous leaf extract of O. majorana contains flavonoids, tannins, and phenolic derivatives, which serve as reducing and capping agents for the biosynthesis of ZnO-NPs. These extracts also contain functional groups such as -OH and -C=O, which further enhance the physicochemical properties of the resulting ZnO-NPs and influence their ability to target specific molecules. The plant-mediated synthesis of ZnO-NPs using O. majorana leaf extract is not only fast and straightforward but also offers a wide range of functionalized nanoparticles with specific morphologies and sizes. These ZnO-NPs prepared with O. majorana have been shown to have potential applications in various fields, including antimicrobial, antioxidant, and anticancer activities. This review focuses specifically on the antimicrobial applications of ZnO-NPs synthesized using O. majorana leaf extract.

Controlled synthesis of zinc oxide nanoparticles through flame spray pyrolysis and evaluation of their anticancer effects against gastric cancer cell

Zinc oxide nanoparticles (ZnO NPs) have drawn some attention due to its antimicrobial properties and potential for their usage in biomedicine. ZnO NPs were synthesized using algal biomass filtrate, characterized subsequently, and the antimicrobial, antibiofilm, and cytotoxic activities of the ZnO NPs were evaluated. The synthesized ZnO NPs were characterized with fourier transform infrared, X‐ray Diffraction, scanning electron microscopic, and transmission electron microscopy to analyze their morphological and compositional properties. Agar well diffusion, time‐kill assays and antibiofilm experiments were conducted to assess antibacterial efficacy, while Artemia salina nauplii were used to evaluate cytotoxicity. It was found that ZnO NPs had hexagonal wurtzite crystal structure, uniform nanoscale morphology ranging 20–90 nm, and high phase purity. ZnO NPs exhibited potent antibacterial activity, further confirmed by molecular docking analysis. Strong antibiofilm efficacy, reducing biofilm biomass by up to 95%. Exceptional results were shown by wet lab and docking validation. The PBP2a protein of S. aureus showed a binding score of −7.7, indicating strong inhibition by the ZnO NPs. These nanoparticles exhibit a dose‐dependent response, where minimal toxicity was observed at lower concentrations. This study highlights the potential of algae‐mediated ZnO NPs as a green, sustainable antimicrobial platform that may mitigate the microbial resistance problem.

In recent years, there has been a significant focus on the green synthetization of metal oxide nanoparticles due to their environmentally friendly features and cost-effectiveness. The aim of this study is to biosynthesize zinc oxide nanoparticles (ZnO NPs) through a green method, utilizing crude banana peel extract as reducing and capping agents, to characterize the synthesized ZnO NPs and test their antibacterial activity. ZnO NPs were biosynthesized using the peel extract of banana with various concentrations of zinc acetate dihydrate salt, followed by annealing at 400 °C for 2 h. The synthesized ZnO NPs were characterized using UV–visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), dynamic light scattering (DLS), attenuated total reflectance–Fourier-transform infrared (ATR-FTIR), and X-ray diffraction (XRD). Also, its antibacterial efficiency against different bacterial strains was tested. ZnO NPs were biosynthesized successfully using the extract of Musa Acumniata (cavendish) fruit peel with a UV-Vis wavelength range of 344 to 369 nm and an electrical band gap ranging from 3.36 to 3.61 eV. The size varied from 27 ± 4 nm to 89 ± 22, and the negative zeta potential (ζ) ranged from −14.72 ± 0.77 to −7.43 ± 0.35 mV. ATR-FTIR analysis showed that the extract phytochemical functional groups were present on ZnO NPs. XRD results confirm the formation of a highly pure wurtzite hexagonal structure of ZnO NPs. Moreover, the best obtained size of ZnO NPs was selected for the antibacterial tests, giving the highest inhibition growth rate against Staphylococcus epidermidis (98.6 ± 0.9%), while the lowest rate was against Pseudomonas aeruginosa (88.4 ± 4.4%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were reported and compared to previous studies. The unique properties of greenly synthesized ZnO NPs and their antibacterial activity have potential for reducing environmental pollution and the use of antibiotics, which may contribute to solving the problem of bacterial resistance. Therefore, studies that aim to design an applicable dosage form loaded with biosynthesized ZnO NPs might be conducted in the future.

Background: The fruit peel wastes produced during the processing of different agriculture-related products after production are not utilized to their full potential, and their environmental impact has become a significant global issue. Citrus peel waste is rich in nutrients and has biopotential activity. Objective: The main objective of the current study is to analyze peels of Citrus limetta qualitatively and quantitatively and synthesize Zinc oxide Nanoparticles using the green synthesis method. Methodology: The synthesized ZnO NPs were characterized by UV-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), and Scanning electron microscopy (SEM). The antibacterial activity of C. limetta peels ZnO NPs against Pseudomonas aeruginosa was evaluated by the Agar Disc Diffusion method. Results: The UV-Vis spectrum was measured in the 200 – 400 nm range, and the crystalline structure was analyzed via XRD. SEM/EDS analysis confirmed the nano-spherical structures and the agglomeration of the synthesized ZnO NPs. A minimal inhibitory effect against the Pseudomonas aeruginosa by C. limetta peels ZnO NPs was observed. Conclusion: Hence, the green synthesized ZnO NPs offer an effective and economical way to utilize citrus peel waste in both food and non-food sectors.

In this study, green synthesis methods were employed to fabricate zinc oxide nanoparticles (ZnONPs) using Newbouldia laevis leaves plant extract. Several analytical methods, including Fourier-Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), and UV-Vis spectrophotometer, were used to characterise the green synthesised ZnONPs. The synthesis of ZnONPs with distinct properties was successfully demonstrated by the structural and morphological investigations. The existence of functional groups involved in the stabilisation and reduction of the nanoparticles was established by FTIR. The shape of the nanoparticles was revealed by TEM. It produced non-spherical particles with a well-defined size distribution, a crystalline structure with a hexagonal shape morphology, and an average nanoparticle size of 34.8 nm. The ZnONPs that were green-synthesised demonstrated unique antioxidant characteristics. The findings showed that the ZnONPs’ capacity to scavenge radicals increased in a concentration-dependent manner. Excellent antifungal activities against Trichophyton rubrum, Aspergilus fumigatus, and Candida albicans were also demonstrated by the synthesised ZnONPs. This suggests that at 100, 200, and 400 mg/mL, the environmentally friendly ZnONPs show inhibitory zones that range from 9 to 18 mm. The use green synthesized ZnO NPs have shown excellent antifungal, antioxidant and photocatalytic reduction of 4-nitrophenol under sunlight. Green synthesis, zinc oxide nanoparticles, 4-ntrophenol, Trichophyton rubrum.

Pathogenic microorganisms and cancer continue to be the most difficult problem in public health care and the incidence of diseases caused by such resistant strains and cancer cells are growing. Recent advances in nanotechnology open up new possibilities for creating novel, exciting nanoparticles that are safe for human cells and may be used as smart antibacterial and anticancer medicines. The novelty of the present study is the extracellular green synthesis of zinc oxide nanoparticles (ZnO NPs), and gold (Au) NPs using the cell filtrate of the endophytic fungus Fusarium chlamydosporum MW341592.1 isolated from healthy leaves of Eucalyptus sideroxylon plant. Eco-friendly synthesized ZnO NPs and Au NPs were screening for their activity against select carcinomic cell lines and some multidrug-resistant bacteria. The synthesized ZnO NPs and Au NPs were characterized by UV-Vis. spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), transition electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The UV-Vis. absorption spectra of the produced ZnO NPs showed bands in the UV area at 320 nm, whereas the Au NPs showed bands in the UV region at 530 nm. TEM revealed average sizes for ZnO NPs, and Au NPs as 19.3 nm and 22.1 nm, respectively, while shape revealed both ZnO NPs and Au NPs with spherical-like shape. Biological assay showed that raising in the synthesized NP concentration lowers the number of HCT-116 human colon cancer cells and CACO2 human intestinal cancer cells, as well as associated pathogens such as Escherichia coli and Pseudomonas aeruginosa.

Zinc oxide nanoparticles (ZnO NPs) are one of the most abundant metal oxides nanoparticles. It provides excellent thermal, electrical and chemical stabilities with low biotoxicity; its photo-oxidising and photo-catalytic impact on biological and chemical species is of great importance, thereby making it a promising candidate to be used for in-vitro and in-vivo studies in biomedical field. Hereby, ZnO NPs were synthesized using precipitation method with zinc acetate and sodium hydroxide as starting materials. This study has characterized the synthesized ZnO NPs using different techniques such as UV-Visible spectroscopy indicating a peak at 365 nm wave length, size of ZnO NPs was determined to be 286.7 nm by measuring hydrodynamic radii using Dynamic Light Scattering (DLS) phenomena. Further predominant charge existing at surface of the synthesised ZnO NPs was evaluated to be 31.6mV. Anti-microbial activity of ZnO NPs was determined by Kirby-Bauer method for both Gram-positive and Gram-negative bacteria, S. aureus and E. colirespectively. Anti-microbial activity was determined as Zone of Inhibition that measures both bactericidal and bacteriostatic activity of ZnO NPs and was found to be more potent for Gram-positive (S. aureus)bacteria and its activity increased with increasing concentration of nanoparticles. Growth kinetics was studied to determine percentage growth inhibition, for this optical density was recorded as a function of time in bacterial culture broth with and without treatment. Further DNA fragmentation assay was performed to determine genotoxicity caused by nanoparticles and its effect on genomic DNA of bacteria. Highlighting its potential role as a nano-carrier system for leading antibacterial drugs for enhanced effectiveness of the antibacterial therapies

Creating a sustainable and effective approach to handling organic contaminants from industrial waste is an ongoing problem. In the present study, ZnO nanoparticles (ZnO NPs) were synthesized under a controlled ultrasound cavitation technique using the extract of Passiflora foetida fruit peels, which act as a reducing (i.e., reduction of metal salt) and stabilizing agent. The formation of monodispersed and hexagonal morphology (average size approximately 58 nm with BET surface area 30.83m2/g). The synthesized ZnO NPs were characterized by a various technique such as UV–visible spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and Dynamic light scattering (DLS). Further, the XRD pattern confirmed the hexagonal wurtzite structure of synthesized ZnONPs. The ZnO NPs exhibit excellent degradation efficiency towards organic pollutant dyes, i.e., Methylene blue (MB) (93.25% removal) and Rhodamine B (91.06% removal) in 70 min, under natural sunlight with apparent rate constant 0.0337 min−1 (R2 = 0.9749) and 0.0347 min−1 (R2 = 0.9026) respectively.Zeta potential study shows the presence of a negative charge on the surface of ZnO NPs. The use of green synthesized ZnO NPs is a good choice for wastewater treatment, given their high reusability and photocatalytic efficiency, along with adaptability to green synthesis.

Green synthesis of zinc oxide nanoparticles using Cinnamomum camphora (L.) Presl leaf extracts and its antifungal activity

Green synthesis of zinc oxide nanoparticles (ZnO NPs) using plant extracts have recently attracted considerable attention due to their environmental protection benefits and their easy and low cost of fabrication. In the current study, ZnO NPS were synthesized using the aqueous extract of Ochradenus arabicus as a capping and reducing agent. The obtained ZnO NPs were firstly characterized using ultraviolet visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR), transmission electron microscope (TEM), X-ray diffraction (XRD), energy dispersive X-ray absorption (EDX), zeta potential, and zeta size. All these techniques confirmed the characteristic features of the biogenic synthesized ZnO NPs. Then, ZnO NPs were evaluated for their effects on morphological, biochemical, and physiological parameters of Salvia officinalis cultured in Murashige and Skoog medium containing 0, 75, 100, and 150 mM of NaCl. The results showed that ZnO NPs at a dose of 10 mg/L significantly increased the shoot number, shoot fresh weight, and shoot dry weight of Salvia officinalis subjected or not to the salt stress. For the shoot length, a slight increase of 4.3% was recorded in the plant treated by 150 mM NaCl+10 mg/L ZnO NPs compared to the plant treated only with 150 mM of NaCl. On the other hand, without NaCl, the application of both concentrations 10 mg/L and 30 mg/L of ZnO NPs significantly improved the total chlorophyll content by 30.3% and 21.8%, respectively. Under 150 mM of NaCl, the addition of 10 mg/L of ZnO NPs enhanced the total chlorophyll by 1.5 times, whilst a slight decrease of total chlorophyll was recorded in the plants treated by 150 mM NaCl + 30 mg/L ZnO NPs. Additionally, ZnO NPs significantly enhance the proline accumulation and the antioxidative enzyme activities of catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) in plants under salinity. Our findings revealed that green synthesized ZnO NPs, especially at a dose of 10 mg/L, play a crucial role in growth enhancement and salt stress mitigation. Hence, this biosynthesized ZnO NPs at a concentration of 10 mg/L can be considered as effective nanofertilizers for the plants grown in salty areas.

The present study reports an eco-friendly green synthesis of zinc oxide nanoparticles (ZnO NPs) using the bioflavonoid rutin. The synthesized ZnO NPs were characterized by UV–visible spectroscopy, XRD, FE-SEM, EDX, FTIR and zeta potential analyses. FE-SEM image showed that the synthesized ZnO NPs were rod shaped. FTIR spectral studies confirmed the role of bioflavonoid rutin for the reduction, capping and synthesis of ZnO NPs. The green synthesized ZnO NPs showed significant antibacterial activity against both Gram-positive (B. subtilis and S. aureus) and Gram-negative (K. pneumoniae and E. coli) bacterial pathogens. However, the synthesized ZnO NPs were more effective against Gram-negative bacteria compared to Gram-positive bacteria. The in vitro antioxidant ability of ZnO NPs was investigated spectrophotometrically using DPPH and H2O2 assay. The percentage of antioxidant activity increased with increasing concentration of ZnO NPs. Furthermore, synthesized ZnO NPs showed effectiveness in inhibiting the human MCF-7 breast cancer cells. In conclusion, the synthesized ZnO NPs using bioflavonoid rutin might be used as a strong biocidal and antioxidant agent in biomedical and pharmaceutical industries.

Background: Tick population in India has developed resistance against all commonly available acaricides and there have been only limited research activities to develop novel acaricides due to the enormous costs involved. Therefore, alternative therapy is need of the hour to tackle the acaricidal resistance. Methods: The present study envisages Annona squamosa seed based synthesis of ZnO nanoparticles (ZnO-NPs) for its acaricidal potential. Mean size of ZnO-NPs was 292.75 nm as per scanning electron microscope. Zeta potential of ZnO-NPs was (-) 38.9 mV. ZnO-NPs showed characteristic intense peaks in XRD analysis at 2θ of 31.89°and 45.64° due to its crystalline nature. In FTIR, the peak observed at 3754.73 cm-1 may be due to (-) OH stretching and deformation. ZnO NPs showed a strong absorbance peak at 300 nm confirmed the stability of nanoparticles. Result: Critical analysis of reproductive index study with ZnO-NPs revealed consistent acaricidal property of 2% ZnO-NPs even in the next generation of tick. Cytotoxicity evaluation revealed absence of aggregation as well other morphological changes of RBC, which indicated safer use of synthesized ZnO NPs on the animal body.

Background:The Zinc oxide Nanoparticles (ZnO NPs) were synthesized successfully by using Tagetes erecta flower aqueous extract and evaluated for their antioxidant potential, antimicrobial and cytotoxic potential.Methods:Phytochemical screening of aqueous crude extract and synthesized ZnO NPs of Tagetes erecta flower revealed the presence of alkaloids, flavonoids, carbohydrates, amino acids, tannins, proteins, etc. The characterization was done by various spectral analyses. In vitro antioxidant activities of synthesized ZnO NPs were found to possess concentration-dependent free radical scavenging activity was carried on different free radicals i.e. DPPH and ABTS. Antimicrobial activity of synthesized ZnO NPs was performed by agar well diffusion method and compared with control ampicillin, while cytotoxic effects were determined by MTT assay against human cervical cancer cell line.Results:UV-Visible spectra were conducted to confirm the synthesis of ZnO NPs and peak obtained at 364.15nm. X-ray analysis confirmed the crystalline nature of the nanoparticles and the average size of the nanoparticles was 30-50nm and was spherical shape analyzed by SEM. The synthesized ZnO NPs showed antimicrobial activity against all tested microorganisms and a maximum inhibition zone was found against E. coli in gram-negative and S. aureus in gram-positive bacteria. Synthesized ZnO NPs were showed 50% cell viability at 26.53μg/ml against the HeLa cancer cell line.Conclusion:The conclusion of this study suggests both the aqueous crude extract of Tagetes erecta flower and synthesized ZnO NPs showed an excellent alternative source of antimicrobial agent also an attractive selective cytotoxic activity against HeLa tested cancer lines, offering satisfying ‘safe and cheaper’ alternatives to conventional therapy protocols.