Biogenic ZnO nanoparticles: structural characterisation and bioactivity evaluation

Nanoparticles of zinc oxide (ZnO NPs), propolis, and the ZnO–propolis composite (ZnO-P NCs) have been synthesized using a biomimetic approach. Zeta potential analysis and Fourier-transform infrared spectroscopy (FT-IR) proved the formation and stability of nanomaterials. Findings using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), EDX-imaging, and transmission electron microscopy (TEM) demonstrated that the particle size of ZnO-P NCs was 9.70 nm. The antioxidant (DPPH radical scavenging) activity of synthesized nanomaterials was investigated. IC50 values of zinc oxide, propolis, and ZnO-P NCs nanoparticles were 2.75, 1.7, and 1.45 mg mL−1, respectively. In addition, their selectivity and anticancer activity for cancer cell lines (Hela and MCF-7) and human normal (W138) cell lines were investigated. ZnO-P NCs were highly effective against the cell line for breast cancer with an IC50 value of 18 µg/mL, indicating its anticancer-promising potent cytotoxicity in breast cancer treatment, and 23 µg/mL against cervical cancer. In addition, the higher observed safety, antioxidant, and anticancer activities for synthesized ZnO-P NCs confirmed the synergistic effect of this combination. It was obtained that the specific mechanisms underlying the synergy effect between zinc oxide nanoparticles and nanopropolis in their composite formulation varied depending on the preparation method, ratio, and concentration of the components.

This study explores the green synthesis of zinc oxide nanoparticles (ZnONPs) using Tamarix chinensis extract, known for its hepatoprotective and anti-inflammatory phytochemicals. The ZnONPs were synthesized using ZnSO4 and NaOH, resulting in an average size of 125 nm, as confirmed by scanning electron microscopy (SEM). X-ray diffraction (XRD) analysis revealed a hexagonal crystalline structure. UV-Vis spectroscopy showed an absorption peak at 360 nm, corresponding to a bandgap of 3.37 eV, making these nanoparticles suitable for controlled drug delivery systems. The antioxidant activity of T. chinensis extract was evaluated using the DPPH assay, demonstrating an 80% inhibition of free radicals at 500 µg/mL, surpassing the antioxidant potential of the ZnONPs. The antimicrobial efficacy of the ZnONPs was evidenced by a minimum inhibitory concentration (MIC) of <50 µg/mL against Escherichia coli and Staphylococcus aureus. Additionally, the ZnONPs exhibited antiproliferative activity with an IC50 of 20.80 µg/mL in MCF-7 breast cancer cells, highlighting their potential for biomedical applications. These findings suggest the promising multifunctional role of biosynthesized ZnONPs in healthcare and technological innovations.

Green synthesis of ZnO nanoparticles using Abutilon Indicum and Tectona Grandis leaf extracts for evaluation of anti-diabetic, anti-inflammatory and in-vitro cytotoxicity activities

Zinc oxide nanoparticles can be classified as a multipurpose material, along with their distinctive features and applications in optoelectronic devices. This research looks at the morphological, structural, and optical features of zinc oxide (ZnO) nanoparticles. The sol-gel procedure has been used to form zinc oxide nanoparticles with zinc nitrate [Zn (NO3)2.4H2O] and sodium hydroxide [NaOH] as precursors. The main objective is to synthesize zinc oxide (ZnO) nanoparticles by using the sol-gel approach because that is easy to implement and offers the capacity to adjust particle size and morphology by systematically monitoring reaction conditions. X-ray diffraction phenomenon, Scanning Electron Microscopy, and Ultraviolet-vis spectroscopy characterization techniques were used to determine the structural, morphological, and optical features of produced zinc oxide nanoparticles. According to the XRD examination, the produced nanoparticles are in a highly crystalline phase nature. The high crystallinity of ZnO is observed in all diffraction peaks, implying that Zinc oxide nanoparticles were synthesized properly using the sol-gel process. The UV-vis spectroscopy produced an absorption spectrum at 370nm due to ZnO nanoparticles. The Scanning Electron Microscopy (SEM) measurements reveal the surface structure and grains size of zinc oxide (ZnO) nanoparticles at a different resolution.

Green synthesis, characterization, structural, morphological, antibacterial, and cytotoxicity evaluation of zinc oxide nanoparticles using Fioria vitifolia extract.

In the present work, bioaugmented zinc oxide nanoparticles (ZnO-NPs) were prepared from aqueous fruit extracts of Myristica fragrans. The ZnO-NPs were characterized by different techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and thermogravimetric analysis (TGA). The crystallites exhibited a mean size of 41.23 nm measured via XRD and were highly pure, while SEM and TEM analyses of synthesized NPs confirmed their spherical or elliptical shape. The functional groups responsible for stabilizing and capping of ZnO-NPs were confirmed using FTIR analysis. The ζ-size and ζ-potential of synthesized ZnO-NPs were reported as 66 nm and −22.1 mV, respectively, via the DLS technique can be considered as moderate stable colloidal solution. Synthesized NPs were used to evaluate for their possible antibacterial, antidiabetic, antioxidant, antiparasitic, and larvicidal properties. The NPs were found to be highly active against bacterial strains both coated with antibiotics and alone. Klebsiella pneumoniae was found to be the most sensitive strain against NPs (27 ± 1.73) and against NPs coated with imipinem (26 ± 1.5). ZnO-NPs displayed outstanding inhibitory potential against enzymes protein kinase (12.23 ± 0.42), α-amylase (73.23 ± 0.42), and α-glucosidase (65.21 ± 0.49). Overall, the synthesized NPs have shown significant larvicidal activity (77.3 ± 1.8) against Aedes aegypti, the mosquitoes involved in the transmission of dengue fever. Similarly, tremendous leishmanicidal activity was also observed against both the promastigote (71.50 ± 0.70) and amastigote (61.41 ± 0.71) forms of the parasite. The biosynthesized NPs were found to be excellent antioxidant and biocompatible nanomaterials. Biosynthesized ZnO-NPs were also used as photocatalytic agents, resulting in 88% degradation of methylene blue dye in 140 min. Owing to their eco-friendly synthesis, nontoxicity, and biocompatible nature, ZnO-NPs synthesized from M. fragrans can be exploited as potential candidates for biomedical and environmental applications.

Owing to the development of nanotechnology, biosynthesis of nanoparticles (NPs) is gaining considerable attention as a cost-effective and eco-friendly approach that minimizes the effects of toxic chemicals used in NP fabrication. The present work reports low-cost phytofabrication of zinc oxide (ZnO) NPs employing aqueous extracts of various parts (leaves, stems, and inflorescences) of Tephrosia purpurea (T. purpurea). The formation, structure, morphology, and other physicochemical properties of ZnO NPs were characterized by ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS). UV–Vis spectral analysis revealed sharp surface plasmon resonance (SPR) at around 250–280 nm, while the XRD patterns confirmed distinctive peaks indices to the crystalline planes of hexagonal wurtzite ZnO NPs. TEM analysis confirmed the presence of spherical-shaped ZnO NPs with average particle sizes (PS) between 25–35 nm, which was in agreement with the XRD results. FTIR analysis revealed that phenolics, flavonoids, amides, alkaloids, and amines present in the plant extract are responsible for the stabilization of the ZnO NPs. Further, the hydrodynamic diameter in the range of 85–150 nm was measured using the DLS technique. The fluorescence resonance energy transfer (FRET) ability of biogenic ZnO NPs was evaluated, and the highest efficiency was found in ZnO NPs synthesized via T. purpurea inflorescences extract. Photoluminescence (PL) spectra of biogenic ZnO NPs showed three emission peaks consisting of a UV–Vis region with high-intensity compared to that of chemically synthesized ZnO NPs. The biosynthesized ZnO NPs showed photocatalytic activity under solar irradiation by enhancing the degradation rate of methylene blue (MB). Among the prepared biogenic ZnO NPs, T. purpurea leaves mediated with NPs acted as the most effective photocatalyst, with a maximum degradation efficiency of 98.86% and a half-life of 84.7 min. This is the first report related to the synthesis of multifunctional ZnO NPs using T. purpurea, with interesting characteristics for various potential applications in the future.

The green synthesis of nanoparticles using plant extracts has garnered significant attention as a reliable and sustainable method for producing functional nanomaterials. Among these, zinc oxide (ZnO) nanoparticles are extensively studied for their potential biological applications. In this study, ZnO nanoparticles were synthesized through a green synthesis approach using an aqueous extract of Musa acuminata leaves and zinc acetate as precursors. The resulting nanoparticles were characterized using ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction analysis (XRD), energy-dispersive x-ray analysis (EDX), and scanning electron microscopy (SEM). The UV-Vis spectra revealed characteristic absorption peaks around 350 nm, attributed to the nanoparticles' large excitation binding energy at room temperature. FTIR analyses confirmed the formation of zinc oxide chemical bonds, while XRD results indicated a hexagonal wurtzite crystal structure. SEM analysis showed that the nanoparticles had a nearly cuboid shape, and EDX analysis confirmed their high purity. The minimum inhibitory concentrations (MIC) of the synthesized ZnO nanoparticles were evaluated against Staphylococcus aureus and Escherichia coli cultures. Cotton wound bandages impregnated with ZnO nanoparticles at concentrations near the calculated MIC demonstrated significant antibacterial activity invitro. These antimicrobial bandages show potential for use in treating and protecting infection-prone wounds, such as diabetic or burn-related injuries.

Zinc oxide nanoparticles (ZnO-NPs) have provided promising potential in the biomedical field, including the ability to overcome various health problems. Diosgenin is used to treat multiple health disorders but has very low solubility in water. Using ZnO-NPs as a diosgenin delivery vehicle was expected to increase the solubility of diosgenin, which would affect its bioavailability. This study demonstrates phytofabrication and characterization of ZnO-NPs, loading of diosgenin onto the ZnO-NPs, characterization of the product (ZnO-NPs/diosgenin), and evaluations of diosgenin release. Phytofabrication of the ZnO-NPs was carried out with zinc precursors and Hibiscus tiliaceus leaf extract (HLE) obtained with various extraction solvents. To explore the potential of using the ZnO-NPs as a diosgenin delivery vehicle, diosgenin release from the ZnO-NPs/diosgenin was studied. Based on the X-ray fluorescence (XRF) and X-ray diffraction (XRD) results, ZnO-NPs with high purity have been successfully fabricated. Nano-sized particles were detected using scanning electron microscopy (SEM) and confirmed by transmission electron microscopy (TEM), revealing the smallest particle size of 45.924 ± 27.910 nm obtained from the methanol extract with the zinc acetate precursor. The ZnO-NPs had hexagonal wurtzite and rod-like structures. Diosgenin was successfully added to the ZnO-NPs with loadings of 79.972% for ZnO-HLMEA-D500 (ZnO-NPs/diosgenin produced by doping with a 500 μg mL-1 of diosgenin solution) and 39.775% for ZnO-HLMEA-D1000 (ZnO-NPs/diosgenin produced by doping with a 1000 μg mL-1 of diosgenin solution). The solubilities of diosgenin from ZnO-HLMEA-D500 and ZnO-HLMEA-D1000 were higher than that of free diosgenin, confirming that ZnO-NPs have potential as delivery vehicles for diosgenin and conceivably other water-insoluble drugs.

Green synthesis of zinc oxide nanoparticles using Pisonia Alba leaf extract and its antibacterial activity

In the present study, zinc oxide (ZnO) nanoparticles were prepared using ZnCl2.2H2O as a precursor, via green route using leaf extract of Rhazya stricta as capping and reducing agent. The prepared ZnO nanoparticles were examined using UV-visible spectrophotometer (UV-Vis), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction spectrometer (XRD), and scanning electron microscope (SEM). The UV-Vis absorption spectrum at 355 nm showed an absorption peak, which indicates the formation of ZnO NPs. The FT-IR spectra analysis was performed to identify the potential biomolecule of the as-prepared ZnO NPs. The FT-IR spectra showed peaks at 3455, 1438, 883, and 671 cm−1 in the region of 4000–500 cm−1, which indicates –OH, NH, C-H, and M-O groups, respectively. The SEM images showed aggregation of ZnO nanoparticles with an average size of 70–90 nm. The XRD study indicated that the ZnO NPs were crystalline in nature with hexagonal wurtzite structure and broad peaks were observed at 2 theta positions 31.8°, 34.44°, 36.29°, 47.57°, 56.61°, 67.96°, and 69.07°. The synthesized ZnO NPs were found to be good antiplasmodial with a 50% inhibitory concentration (IC50) value of 3.41 μg/mL. It is concluded from the current study that the ZnO NPs exhibited noble antiplasmodial activity, and for the improvement of antiplasmodial medications, it might be used after further in vivo studies.

This study aimed to evaluate dental adhesives containing different concentrations of zinc oxide nanoparticles (ZnO-NPs) for their use in the treatment of dental fluorosis, observe the interaction of the adhesive on healthy enamel surfaces and with mild and moderate fluorosis, measure the adhesive strength and fluorosis, and determine the phosphorus (P) and calcium (Ca) content on these surfaces, as a reference for the potential use of this adhesive with ZnO-NPs for dental fluorosis treatment. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to characterise the ZnO-NPs and analyse the weight percentages of P and Ca in the enamel using X-ray energy dispersive spectroscopy (EDS) and the adhesive strength using a universal mechanical testing machine. FESEM characterisation revealed that the ZnO-NPs were less than 100nm in size, with quasi-spherical and hexagonal prism shapes. The synthesis of the ZnO-NPs was confirmed by TEM, revealing their hexagonal crystalline structure. The adhesive strength by the universal mechanical testing machine showed that the adhesive with a 3% wt. concentration of ZnO-NPs was better in the three groups of teeth, showing higher adhesive strength in teeth with mild (15.15MPa) and moderate (12.76MPa) fluorosis surfaces, and was even higher than that in healthy teeth (9.65MPa). EDS analysis showed that teeth with mild and moderate fluorosis had the highest weight percentages of P and Ca, but there were no statistically significant differences compared to healthy teeth and teeth treated with adhesives. Lay description: This study focused on testing a new dental adhesive containing small particles called ZnO nanoparticles (ZnO-NPs). This study aimed to demonstrate whether this adhesive with ZnO-NPs could be useful for treating dental fluorosis by improving its adhesion to teeth. One of the first objectives was to determine whether the dental adhesive could adhere better to teeth affected by mild or moderate fluorosis than to healthy teeth by measuring whether the levels of two important elements for healthy teeth, calcium (Ca) and phosphorus (P), were affected by the adhesive. The size and shape of the small particles and teeth with mild or moderate fluorosis were observed using scanning electron microscopy. The nanoparticles were small (< 100nm) and had specific quasi-spherical and hexagonal prismatic shapes. More damage to the enamel was observed in teeth with mild or moderate fluorosis than in healthy teeth. The adhesive strength test demonstrated that the dental adhesive with 3% ZnO-NPs had the best adhesion on all healthy conditions of teeth. It was particularly effective in teeth with mild or moderate fluorosis. Finally, the evaluation of the levels of P and Ca on the enamel showed that teeth with fluorosis had higher levels of these elements, but using the dental adhesive with ZnO-NPs did not change the levels of these elements significantly because the adhesive avoided greater detachment because of greater adhesion to these surfaces. In conclusion, adding these small particles to dental adhesives could be an option for treating teeth affected by fluorosis. It stuck well and did not affect the levels of the important elements in the teeth.

Antibacterial, antioxidant and photodegradation potential of ZnO nanoparticles mediated via roots of Taraxacum officinale radix

Zinc oxide (ZnO) nanoparticles have been successfully synthesized by using Terminalia arjuna bark extract via a green route. Structural analysis using X-ray diffraction confirmed the prepared samples are crystalline having hexagonal wurtzite structure with space group P63 mc and average crystallite size is found to be 8.93 nm. Rietveld refinement of the data was carried out using Material Analysis Using Diffraction (MAUD) software and reliability parameters of the refinement have been obtained. Optical properties of the sample investigated by ultraviolet – visible diffuse reflectance spectroscopy reveal an absorption peak to lie at 348 nm and the direct optical band gap energy using Kubelka–Munk function is found to be 3.20 eV. Morphological investigation using scanning electron microscopy revealed that ZnO nanoparticles are nearly spherical and agglomerated. Energy-dispersive X-ray spectrometry analysis showed the presence of Zn and O only. Transmission electron microscopy imaging confirmed the predominant hexagonal structure of the prepared nanoparticles having average particles size of 9.66 nm, which is in agreement with the X-ray diffraction result. Fourier transform infrared spectroscopy was used to identify the functional groups and different vibrational modes present in the sample. The photocatalytic activity of the prepared ZnO nanoparticles was studied using methylene blue (MB) dye under a single wavelength UV light source (λ = 254 nm). The degree of degradation of MB solution was about 56 % within 120 min of illumination to UV light and the degradation reaction follows first order kinetics with rate constant 0.00434 min−1.

In this study, a green route has been adopted to successfully synthesize pure zinc oxide nanoparticles (ZnONPs) as well as Cu doped zinc oxide nanoparticles (Cu-ZnONPs) which is quite a novel work. The synthesized nanoparticles (NPs) were used as adsorbent for removal of Congo red (CR) dye from aqueous solution and efficiency of both doped and undoped ZnONPs was investigated and evaluated. The synthesized products were further characterized and confirmed by UV–visible (UV–vis), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), Thermo gravimetric Analysis (TGA), Transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Cu-ZnONPs were found to be more efficient adsorbent as compared to undoped ZnONPs. The adsorption process of CR on both the synthesized NPs were scrutinized using kinetics and isothermal parameter respectively, which depicted that the adsorption process in case of doped ZnONPs was faster (adsorption reached equilibrium in 120 min) as compared to undoped ZnONPs (which took 180 min) and followed a pseudo-second-order kinetics in both the cases. When pure ZnONPs was used as adsorbent, it correlated more with the Freundlich isotherm and Temkin isotherm as compared to Langmuir isotherm, however, when Cu-ZnONPs was used as adsorbent, the data fitted well to Langmuir and Freundlich models.