Many fungal endophytes were identified and evaluated for this capacity to find a potentially simple and ecologically acceptable method of producing a variety of nanoparticles (NPs) at a low cost and without the use of hazardous or harmful substances. In this study Zinc Oxide (ZnO) NPs have been synthesized using the filtrate of fungal endophytes isolated from Buchanania lanzan plant. The zinc acetate and the sodium hydroxide were used as the precursors and the fungal filtrate was used as a solvent (reducing agent) to synthesize the ZnO NPs by utilizing the sol-gel method. The biologically synthesized nanoparticles were initially monitored by ultraviolet-visible (UV-Vis) spectroscopy which shows a single plasmon resonance peak of ZnO identified within the 350-400nm range. Further, as-synthesized ZnO NPs were characterized by the x-ray diffraction (XRD), scanning electron microscopy (SEM), and the transmission electron microscopy (TEM) in imaging and diffraction mode. The morphological feature of the ZnO NPs has been analyzed and it was observed that the majority of them are spherical nanoparticles with an average particle size of 17nm, however, few ZnO nano rods were also observed. The selected area electron diffraction (SAED) analysis confirmed the pure synthesized ZnO NPs having hexagonal wurtzite phase with lattice parameters a = b = 3.24Å and c = 5.20Å. According to the results of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and total antioxidant capacity it was found that the synthesized ZnO NPs are very stable and had greater antioxidant activity than the endophytic fungal filtrate. ZnO NPs also exhibited excellent antimicrobial activity with an average inhibition zone of 18mm ( Escherichia coli), 12mm ( Pseudomonas aeuroginosa), 10mm ( Klebsiella sp.), and 6mm ( Staphylococcus aureus).

Green synthesis of ZnO nanoparticles from Cocos nucifera spadix: A sustainable route toward antimicrobial and anti-biofilm applications.

The study highlights the eco-friendly synthesis of zinc oxide (ZnO) nanoparticles utilizing an aqueous extract of the marine red alga Centroceras clavulatum and evaluation of their biofunctional properties. Phytochemical screening confirmed the presence of bioactive compounds such as phenols, flavonoids, alkaloids and terpenoids, with notable Total Phenolic Content (13.45 ± 0.57 mg GAE/g) and Total Flavonoid Content (64.95 ± 10.38 mg QE/g), supporting their role in nanoparticle formation. The synthesized nanoparticles were characterized using UV-visible spectroscopy (λmax = 373 nm and Eg = 3.06 eV), FTIR, DLS, XRD and FESEM-EDX, revealing crystalline, quasi-spherical nanoparticles with an average size of 64.9 nm and high purity. The biofunctional properties of the extract and ZnO nanoparticles were evaluated through in vitro assays. Antioxidant activity assessed by DPPH and phosphomolybdate assays demonstrating a significant free-radical scavenging capacity. Bovine serum albumin and egg albumin assays demonstrated considerable inhibition of anti-inflammatory action, whereas α-amylase and α-glucosidase inhibition studies demonstrated effective enzyme inhibition of antidiabetic activity. Antibacterial activity tested against Staphylococcus aureus and Escherichia coli showed concentration-dependent inhibitory effects. Cytotoxicity studies on NIH3T3 fibroblast cells indicated concentration-dependent moderate cytotoxicity. Overall, the results indicate that ZnO nanoparticles mediated by Centroceras clavulatum possess significant activities with potential biomedical applications.

Objective Green synthesis of zinc oxide (ZnO) nanoparticles (NPs) using the aqueous extract of fruit waste, investigating their antioxidants, antimicrobial, anticancer, and wound healing properties. Significance: This study presents an eco-friendly synthesis of ZnO NPs that repurpose organic fruit waste, contributing to sustainable practices in nanomaterial production. The potential applications of ZnO NPs as antioxidant, antimicrobial, and anticancer agents, as well as their role in wound healing are explored. Methods ZnO NPs were synthesized using the aqueous extract of fruit waste, and were characterized using UV-visible spectroscopy, DLS, XRD, FTIR and SEM-EDX. Antioxidant activity was measured using the DPPH assay. Cytotoxicity was assessed on A549 lung carcinoma cells, and antimicrobial activity was tested against Staphylococcus aureus and Pseudomonas aeruginosa. A gel formulation containing chitosan and Aloe vera (CS-AV)/ZnO NPs was evaluated for wound healing in an infected wound model. Results The synthesized ZnO NPs exhibited nanoscale size, good colloidal stability, and polygonal morphology. They demonstrated strong antioxidant activity, dose-dependent cytotoxicity against A549 cells, and significant antibacterial effects. Incorporation of ZnO NPs into the CS-AV gel markedly enhanced wound healing, achieving complete wound closure by day 21. Histopathological analysis further confirmed improved tissue regeneration, as evidenced by reduced inflammation, increased fibrosis, and well-developed collagen formation. Conclusion Fruit waste-derived ZnO nanoparticles offer promising antimicrobial, antioxidant, anticancer, and wound healing properties.

Conventional agriculture on chemical fertilizers and pesticides has serious environmental and health implications. This necessitates the development of more sustainable and eco-friendly alternatives. This study aimed to synthesize zinc oxide nanoparticles (ZnONPs) using Cassia absus leaf extract via a green synthesis approach and evaluate their dual role as biofertilizers and biopesticides in sustainable agriculture. The biosynthesized ZnONPs were characterized using UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), dynamic light scattering (DLS), and zeta potential analysis. A characteristic absorption peak at 355nm confirmed nanoparticle (NP) formation, whereas XRD analysis revealed a hexagonal wurtzite structure with a crystallite size of 45-55nm. SEM analysis showed spherical to quasi-spherical NPs with an average size of 75nm, whereas DLS indicated a hydrodynamic diameter of 83.5nm and a zeta potential of + 48.7 mV, confirming excellent colloidal stability. The in vitro antibacterial activity of ZnONPs was evaluated against the phytopathogens Ralstonia solanacearum, Xanthomonas euvesicatoria, and Clavibacter michiganensis subsp. michiganensis. Significant inhibition zones of 20mm, 18mm, and 27.5mm, respectively, were observed, with minimum inhibitory concentrations (MICs) of 30, 40, and 20µg/mL. In pot experiments using Capsicum annuum, ZnONPs significantly enhanced plant growth parameters, including plant height, leaf length, and leaf width, with up to a 37% improvement observed at moderate concentrations (5µg/10 mL). These results demonstrate that ZnONPs offer an effective dual strategy for enhancing plant growth and controlling bacterial pathogens, making them promising candidates for sustainable agricultural applications.

ZTO/PVA nanocomposite sheets were successfully fabricated using precipitation and sonochemical routes for ZnO and TiO2 nanoparticle synthesis, respectively, followed by solution casting into the PVA matrix. This process ensured uniform dispersion of ZTO nanoparticles within the polymer matrix and was completed without post-mixing thermal calcination, representing an energy-efficient and novel synthesis route. XRD analysis confirmed the incorporation of nanoparticles and revealed an anatase-to-rutile phase transformation of TiO2 after composite formation. XPS spectra confirmed the presence of Zn, O, and Ti LMM signals, indicating the presence of oxide components within the composite structure. Optical analysis showed a significant reduction in the band gap after ZTO incorporation. The indirect band gap decreased from 3.03 eV for pure PVA to 2.93, 2.72, and 2.5 eV for 2, 5, and 8 wt% ZTO/PVA, respectively, while the direct band gap decreased from 4.59 to 2.72 eV at higher filler loading. Photoluminescence results showed a slight red shift for 2 and 5 wt% ZTO/PVA due to interfacial defect states, followed by a blue shift at 8 wt% associated with near-band-edge emission and phase transformation effects. AFM analysis revealed a significant increase in surface roughness from 9.46 to 131.97 nm as ZTO content increased, indicating nanoparticle aggregation and surface heterogeneity. Thermal analysis demonstrated improved thermal stability and multi-step degradation behaviour. Dielectric measurements showed high permittivity at low frequencies due to interfacial polarisation, with non-Debye relaxation behaviour confirmed by Havriliak–Negami and Cole–Cole analysis. Magnetic measurements indicated predominantly non-magnetic behaviour with a slight enhancement after ZTO incorporation. These findings demonstrate that the addition of ZTO effectively tailors the structural, optical, thermal, dielectric, and magnetic properties of PVA nanocomposites, making them promising for multifunctional dielectric and optoelectronic applications.

Meloidogyne incognita is a highly destructive plant-parasitic nematode responsible for significant yield losses in a wide range of vegetable crops. The present study investigated the phytochemical profile of Selenicereus grandiflorus and its application in the green synthesis of zinc oxide nanoparticles (ZnO NPs), followed by evaluation of their nematicidal activity against M. incognita. ZnO NPs were synthesized using S. grandiflorus plant extract and characterized using UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), confirming the formation of crystalline ZnO nanoparticles. The synthesized ZnO NPs exhibited a characteristic UV-Vis absorption peak at 336nm, confirming their formation within the expected range. XRD analysis revealed a highly crystalline structure with an average crystallite size of 10.48nm, while SEM and TEM observations showed predominantly irregular and spherical morphologies with an average particle size of 24.3nm. Qualitative phytochemical screening revealed the presence of bioactive constituents, including phenolics, flavonoids, alkaloids, and saponins, which likely contributed to nanoparticle synthesis and bioactivity. Both the crude plant extract and the synthesized ZnO NPs exhibited significant nematicidal effects; however, ZnO NPs demonstrated markedly enhanced efficacy. Exposure to ZnO NPs resulted in a concentration- and time-dependent increase in juvenile mortality, reaching 88.5%, 96.3%, and 99.0% at 24, 48, and 72h, respectively, at 1000µg/mL, and 25.83%, 33.5%, and 87.83% at 100µg/mL. Due to elevated control mortality (> 20%) at 48-72h, lethal concentration values were calculated using Abbott-corrected 24h data, yielding LC₅₀ and LC₉₀ values of 354.9µg/mL (95% CI: 287.0-438.8) and 1410.6µg/mL (95% CI: 980.8-2029.0), respectively. These findings demonstrate that S. grandiflorus-mediated ZnO NPs possess strong nematicidal activity at sub-phytotoxic concentrations, highlighting their potential as an eco-friendly nanobiotechnological approach for managing plant-parasitic nematodes in sustainable agriculture.

Gastric carcinoma remains a major cause of cancer-related mortality worldwide, underscoring the need for alternative therapeutic strategies. Zinc oxide nanoparticles (ZnO NPs) have attracted attention in cancer research due to their ability to generate reactive oxygen species (ROS), relative cost-effectiveness, and suitability for green synthesis approaches. In this study, ZnO NPs were synthesized via an eco-friendly biogenic method using Artemisia sieberi, and their anticancer-related effects were evaluated in vitro. ZnO nanoparticles were synthesized using an aqueous extract of Artemisia sieberi and characterized by FE-SEM, DLS, EDS, and XRD. Their biological effects were investigated in human gastric adenocarcinoma (AGS) cells and normal human embryonic kidney (HEK-293) cells. Cytotoxicity was assessed using the MTT assay, apoptosis by flow cytometry, cell migration by a wound healing assay, and gene expression by qRT-PCR. Statistical analysis was performed using one-way ANOVA, with p < 0.05 considered significant. Physicochemical characterization confirmed the formation of spherical to polyhedral ZnO nanoparticles with sizes ranging from 37 to 122nm. The nanoparticles exhibited concentration-dependent cytotoxicity in AGS cells, with an IC₅₀ of approximately 480µg/mL, compared to an IC₅₀ of approximately 1250µg/mL in HEK-293 cells, corresponding to a modest selectivity index (~ 2.6). Flow cytometric analysis demonstrated increased apoptosis in AGS cells, with up to 61.6% apoptotic cells observed at the highest concentration. In addition, ZnO NPs significantly inhibited cancer cell migration. Molecular analysis revealed significant upregulation of p53, Caspase-9, and Caspase-3, suggesting activation of the intrinsic mitochondrial apoptotic pathway. The findings indicate that Artemisia sieberi-derived ZnO nanoparticles can induce apoptosis and inhibit migration in gastric cancer cells in vitro, potentially through a p53-mediated mitochondrial mechanism. Although the observed selectivity toward cancer cells was limited, these results support the preliminary potential of biogenically synthesized ZnO nanoparticles as candidates for further investigation. Additional studies, including in vivo models and broader mechanistic analyses, are required to clarify their therapeutic relevance.

Zinc plays an essential role in glucose metabolism, insulin storage, and antioxidant defense, and its deficiency has been linked to impaired pancreatic β-cell function and increased oxidative stress. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized through a green, plant-mediated approach using aqueous extracts of three commonly consumed millets (Eleusine coracana (finger millet), Pennisetum glaucum (pearl millet), and Panicum sumatrense (little millet)). The millet extracts acted as natural reducing agents during nanoparticle formation, leading to the production of crystalline ZnO nanoparticles under alkaline conditions.The synthesized ZnO NPs were characterized using UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/TEM), dynamic light scattering (DLS), and zeta potential analysis to confirm their phase purity, morphology, crystallinity, and colloidal stability. The nanoparticles exhibited a hexagonal wurtzite ZnO structure with crystallite sizes in the nanometer range, while the hydrodynamic sizes were larger due to surface hydration and aggregation effects.In vitro biological evaluation showed that millet-derived ZnO NPs exhibited dose-dependent inhibition of carbohydrate-digesting enzymes (α-amylase and α-glucosidase) along with moderate inhibition of dipeptidyl peptidase-IV (DPP-IV). Cellular studies using INS-1 pancreatic β-cells and 3T3-L1 adipocytes demonstrated enhanced glucose-stimulated insulin secretion and increased glucose uptake at non-cytotoxic concentrations. In addition, the nanoparticles showed antioxidant activity, as indicated by reduced intracellular reactive oxygen species (ROS) levels and increased activities of endogenous antioxidant enzymes.Overall, this study demonstrates that millet extracts can be effectively used for the green synthesis of ZnO nanoparticles, producing nanomaterials with promising in vitro antidiabetic and antioxidant properties. The comparative evaluation across different millets also provides useful insight into how phytochemical composition influences nanoparticle characteristics and biological performance.

Green synthesis of metal oxide nanoparticles using plant extracts offers an eco-friendly and sustainable approach for developing effective photocatalysts for environmental remediation. The present study reports the green synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous fruit extract of Manilkara zapota as a reducing and stabilising agent, with zinc nitrate as the precursor salt. The synthesised nanoparticles were characterised using Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Analysis (EDX), and X-ray Diffraction (XRD). FT-IR analysis revealed the presence of hydroxyl, amine, carbonyl, and alkyl functional groups involved in nanoparticle formation and stabilisation. FESEM micrographs showed predominantly spherical nanoparticles with slight agglomeration and an average particle size of approximately 35 nm. EDX analysis confirmed the elemental composition of zinc and oxygen, while XRD patterns verified the crystalline wurtzite structure of ZnO with an average crystallite size of 26.99 nm. The antioxidant potential of the nanoparticles was evaluated using the DPPH free radical scavenging assay and demonstrated appreciable antioxidant activity. Furthermore, the photocatalytic performance of the ZnO nanoparticles was assessed using methylene blue dye as a model pollutant under xenon lamp irradiation. The nanoparticles exhibited significant dye degradation efficiency, with degradation increasing progressively with irradiation time. The enhanced photocatalytic activity was attributed to the nanoscale size, high surface area, and abundance of active catalytic sites. The study demonstrates that Manilkara zapota-mediated ZnO nanoparticles are environmentally friendly, cost-effective, and promising materials for wastewater treatment and environmental remediation applications.

Nanotechnology is a fast-growing field with diverse applications in various disciplines. Based on the applications in diverse fields and the medicinal significance, R. roseum was phytochemically investigated and was used for the synthesis of zinc oxide nanoparticles (ZnO-NPs). Biosynthesized NPs were characterized using UV spectrophotometry (UV), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM), and used in antioxidant, antibacterial, and seed nano priming activities. Antibacterial activity was observed against Klebsiella pneumoniae, Bacillus subtilis, Enterococcus faecalis, and Staphylococcus aureus, with the maximum zone of inhibition recorded against S. aureus (23mm ± 0.57) at 1000µg/ml. ZnO-NPs exhibited the highest antioxidant activity (75.2%) at 100µg/mL in comparison with the standard (ascorbic acid), which showed 79% activity at the same concentration. The IC50 value of R. roseum-mediated ZnO-NPs obtained was 35.79 at a 20µg/mL ZnO-NP concentration. Seed priming with R. roseum-mediated ZnO NPs markedly enhanced maize growth, with the highest performance recorded at 200ppm, yielding 3.33 ± 0.40g fresh weight, 3.20 ± 0.1g dry weight, and 6 ± 1 leaves. At this concentration, seedlings also exhibited increased root (13.5 ± 0.57mm) and shoot length (12.6 ± 0.57cm) along with elevated chlorophyll content (34.9 ± 4.57), indicating significant improvement in physiological attributes. Compared to the control, nanoparticle treatment at 50µg/mL increased peroxidase activity from 18.4 to 31.3 U mg⁻1 protein, superoxide dismutase from 22.6 to 36.9 U mg⁻1 protein, and catalase from 15.2 to 27.8 U mg⁻1 protein. In conclusion, green-synthesized ZnO-NPs are effective and can be utilized in agriculture, biomedical, and other fields.

The biological synthesis of nanoparticles (NPs) has attracted because of their non-toxic abilities. We reported the synthesis of ZnO nanoparticles (ZnO NPs) via an extract of the Amycolatopsis roodepoortensis strain EA7. Their physical characteristics were investigated with XRD, FT-IR, SEM, TEM, DLS, EDX, and zeta potential analyses. The toxicity of nanoparticles (NPs) was investigated via antimicrobial and the MTT assays in the HT-29, HEK293, and HDF1BOM cell lines.The expression levels of genes related to apoptosis (ATM, ATR, CHK1, and CHK2), anti apoptose (MMP-9 and Bcl-2), cell death, and cell cycle distribution were determined in the HT-29 cell line. ZnO nanoparticles (ZnO NPs) exhibited stronger antibacterial efficacy against clinical and standard Staphylococcus aureus (250 and 125μg/mL) than Pseudomonas aeruginosa (500μg/mL) by the MIC assay. The anticancer effects of these nanoparticles (NPs) demonstrated a dose‒dependent relationship against HT-29, HEK-293, and HDF1BOM cell lines. The IC50 values were determined to be 47 , 32.88, and 81.37μg/mL for the HT-29, HEK293, and HDF1BOM cell lines, respectively. The levels of genes related to apoptosis (ATM = 2.35 ± 0.293, ATR = 2.87 ± 0.280, CHK1 = 3.67 ± 0.378, and CHK2 = 5.86 ± 0.495) were significantly increased compared to the control (P ≤ 0.0001). However, no significant decrease was observed in the expression of genes associated with cancer development. Flow-cytometric analysis revealed apoptosis induction (P ≤ 0.001) and cell cycle arrest in G0/G1 phase in the HT-29 cells. Given the results presented, this research could be an important step towards further investigations and the development of novel antimicrobial and anticancer therapeutics.

Critical perspective review on green synthesis of zinc oxide nanoparticles: Explored wurtzite phase, characterization and real world applications

Green synthesis of ZnO nanoparticles using Datura stramonium leaf extracts and investigate the antibacterial activity against selected bacterial strains.

This study addresses the growing environmental challenge posed by dyes, which are highly persistent and toxic contaminants that require advanced and sustainable treatment technologies. Zinc oxide nanoparticles (ZnO NPs) were synthesized through a green processing route using Rosa gallica extract as a reducing and stabilizing agent. By varying the extract concentration (2–8% w / v ), the synthesis conditions were optimized, enabling the establishment of clear processing-structure-property relationships. XRD confirmed the formation of the hexagonal wurtzite phase, while FTIR, SEM, TEM, UV–Vis, and photoluminescence analyses demonstrated that increasing the extract concentration led to smaller nanoparticle sizes (from 26 to 11 nm), improved size uniformity, and noticeable modifications in optical behavior consistent with quantum confinement effects. The photocatalytic performance of the synthesized ZnO NPs was evaluated against six model dyes, including azo and cationic dyes. The results demonstrated that both extract concentration and the dye molecular structure strongly influence degradation efficiency. Among the samples, ZnO/RC8 exhibited the highest photocatalytic activity, achieving degradation efficiencies of 78–99% for azo dyes and 93–96% for cationic dyes under UV irradiation. These findings highlight the potential of green-synthesized ZnO nanomaterials as functional photocatalysts with tunable properties for environmental applications. • Green synthesis enabled tunable structure-property control in ZnO nanoparticles. • Rosa gallica extract modulated ZnO crystallite size, defects, and optical behavior. • Structure-property variations dictated degradation of azo and cationic dyes. • ZnO/RC8 from the highest extract concentration delivered the best photocatalytic performance.

Sustainable green synthesis of ZnO nanoparticles for antimicrobial and anticancer applications.

Retraction notice to "Green synthesis of zinc oxide nanoparticles from Sida acuta leaf extract for antibacterial and antioxidant applications, and catalytic degradation of dye through the use of convolutional neural network" [Environ. Res. 258 (2024) 119204

Green synthesis of zinc oxide nanoparticles mediated by marine algae: Trends, challenges and opportunities

Engineered nanomaterials could potentially interact with biomolecules and intracellular processes, as many biological activities take place at the nanoscale level. Conventional anticancer therapies have several limitations, which warrant the introduction of alternative cancer cell killing agents. In the present study, we have synthesized ZnO nanoparticles using orange peel extract and encapsulated them inside polyethylene glycol (PEG), a biocompatible polymer (PEG-ZnO-OP). Different characterization techniques were performed to ensure the proper synthesis of the nanoparticles. The biocompatibility was assessed by the MTT assay using normal fibroblast cells, 3T3L1, hemolysis assay, and zebrafish embryo studies. Finally, the anticancer activity in vitro was estimated by the MTT assay in the lung cancer cell line. The hydrodynamic diameter and zeta potential were 43 nm and -20 mV, respectively, showing an ultrasmall size and moderate stability in an aqueous environment. The XRD data suggested a good crystalline structure; SEM and EDX showed size distribution between 81 nm and 143 nm, and the presence of Zn and O, along with other trace elements, was probably contributed by the orange peel extract. The PEG-ZnO-OP nanoparticles were highly biocompatible up to a dose of 50 μg/mL, as assessed both in vitro and in vivo. Further, the anticancer activity showed a high cell killing effect with an IC50 value of 43.88 μg/ml. This study demonstrated that our synthesized PEG-ZnO-OP nanoparticles were safe to administer and could cause significant cancer cell killing. Future studies involving the anticancer effect in other cell lines and animal models need further exploration.

Green synthesis of CuO and ZnO nanoparticles from edible mushrooms: Characterization and evaluation of antioxidant, antimicrobial, anti-inflammatory and cytotoxicity activities