Mycosynthesis of Zinc oxide nanoparticles using endophytic fungi isolated from Buchanania sp. and its assessment as nanobiopotential.

Zinc oxide (ZnO) nanoparticles were synthesized by ultrasonically-assisted solution process without using any surfactants. The as-synthesized spherical ZnO nanoparticles with diameter of 20 +/- 5 nm possessed crystalline nature with wurtzite hexagonal phase and showed a blue-shifted near band-edge ultra-violet absorption at -340 nm due to quantum confinement effect of ZnO nanoparticles. The as-synthesized ZnO nanoparticles were further formulated as an ink for ink-jet printing application. Jetting and writing of various line patterns on Si and ITO substrates were demonstrated using the as-formulated ZnO ink. UV-treated substrates showed an improvement in the fixation of ink on substrate due to decreased contact angle with controlled surface wettability.

The use of biomass for functional nanomaterial is fascinating. Costus woodsonii was used as a green approach to synthesize zinc oxide (ZnO) nanoparticles from its bulb (flower). The as-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), and transmission electron microscopy (TEM). XRD showed that the commercial ZnO (C-ZnO) and as-synthesized ZnO nanoparticles were of high purity and displayed a hexagonal wurtzite and well crystalline structure. XPS confirms that Zn was in the + 2 chemical state. FT-IR spectroscopy showed some additional peaks on the as-synthesized ZnO only due to a surface coating of the components of the bulb extract. TEM revealed the morphology, particle size, and high purity of the ZnO nanoparticles. The UV-Vis DRS of the as-synthesized ZnO showed a red shift compared to C-ZnO, which was attributed to the surface coating of the as-synthesized ZnO nanoparticles. These studies confirmed the synthesis of ZnO nanoparticles with a lower band gap, i.e., Eg = 2.66–2.79 eV. Therefore, phytogenic synthesis could be a new or alternate pathway for the synthesis of different types of novel nanomaterials with unique characteristics without altering the basic and fundamental structure.

This study provides evidence for the green synthesis of zinc oxide nanoparticles (ZnO NPs) using Vitex negundo leaf extract. The UV–Visible (UV–Vis) spectrum of ZnO NPs and calcinated ZnO NPs (ZnO-C) showed peaks at 370[Formula: see text]nm and 374[Formula: see text]nm, respectively, confirming zinc ion reduction to zinc oxide. The ZnO NPs and calcinated counterparts were further characterized by FTIR, XRD, FE-SEM and EDX. FTIR results revealed the presence of alcoholic and aromatic groups, like flavonoids, in the leaf extract. The XRD pattern showed a distinctive Wurtzite crystalline phase with a hexagonal shape. The Brunauer–Emmett–Teller (BET) analysis data revealed that ZnO’s surface area and pore size is 22.8[Formula: see text]m2/g and 12.9[Formula: see text]nm, whereas ZnO-C exhibited a surface area of 23.5[Formula: see text]m2/g and pore size of 13.1[Formula: see text]nm. The SEM data demonstrated numerous irregular and agglomerated flakes fusing to form a roughly spherical morphology with the size, in the range of 15–20[Formula: see text]nm and 11–16[Formula: see text]nm for ZnO and ZnO-C NPs, respectively. The results of the antimicrobial assay by disc diffusion method and MIC testing revealed that ZnO and ZnO-C NPs exhibited moderate to high antimicrobial activity against various microorganisms, indicating their application against bacterial infection. In addition, the ZnO NPs significantly disrupted the biofilm of Bacillus cereus and Pseudomonas aeruginosa, as confirmed by CV assay and fluorescent microscopy.

In this work, we report a green synthesis of zinc oxide (ZnO) nanoparticles using aqueous and ethanolic extracts of Tradescantia spathacea (purple maguey) as bioreducing and stabilizing agents, which are plant extracts not previously employed for metal oxide nanoparticle synthesis. This method provides an efficient, eco-friendly, and reproducible route to obtain ZnO nanoparticles, while minimizing environmental impact compared to conventional chemical approaches. The extracts were prepared following a standardized protocol, and their phytochemical profiles, including total phenolics, flavonoids, and antioxidant capacity, were quantified via UV-Vis spectroscopy to confirm their reducing potential. ZnO nanoparticles were synthesized using zinc acetate dihydrate as a precursor, with variations in pH and precursor concentration in both aqueous and ethanolic media. UV-Vis spectroscopy confirmed nanoparticle formation, while X-ray diffraction (XRD) revealed a hexagonal wurtzite structure with preferential (101) orientation and lattice parameters a = b = 3.244 Å, c = 5.197 Å. Scanning electron microscopy (SEM) showed agglomerated morphologies, and Fourier transform infrared spectroscopy (FTIR) confirmed the presence of phytochemicals such as quercetin, kaempferol, saponins, and terpenes, along with Zn–O bonding, indicating surface functionalization. Zeta potential measurements showed improved dispersion under alkaline conditions, particularly with ethanolic extracts. This study presents a sustainable synthesis strategy with tunable parameters, highlighting the critical influence of precursor concentration and solvent environment on ZnO nanoparticle formation. Notably, aqueous extracts promote ZnO synthesis at low precursor concentrations, while alkaline conditions are essential when using ethanolic extracts. Compared to other green synthesis methods, this strategy offers control and reproducibility and employs a non-toxic, underexplored plant source rich in phytochemicals, potentially enhancing the crystallinity, surface functionality, and application potential of the resulting ZnO nanoparticles. These materials show promise for applications in photocatalysis, in antimicrobial coatings, in UV-blocking formulations, and as functional additives in optoelectronic and environmental remediation technologies.

Facile synthesis and characterization of zinc oxide nanoparticles and studies of their catalytic activity towards ultrasound-assisted degradation of metronidazole

Nanoparticles (NPs) exhibit distinct features compared to traditional physico-chemical synthesis and they have many applications in a wide range of fields of life sciences such as surface coating agents, catalysts, food packaging, corrosion protection, environmental remediation, electronics, biomedical and antimicrobial. Green-synthesized metal NPs, mainly from plant sources, have gained a lot of attention due to their intrinsic characteristics like eco-friendliness, rapidity and cost-effectiveness. In this study, zinc oxide (ZnO) NPs have been synthesized employing an aqueous leaf extract of Pelargonium odoratissimum (L.) as a reducing agent; subsequently, the biosynthesized ZnO NPs were characterized by ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). Moreover, aqueous plant leaf extract was subjected to both qualitative and quantitative analysis. Antioxidant activity of ZnO NPs was assessed by DPPH assay, with varying concentrations of ZnO NPs, which revealed scavenging activity with IC50 = 28.11 μg mL−1. Furthermore, the anti-bacterial efficacy of the green synthesized ZnO NPs against four foodborne pathogenic bacterial strains was examined using the disk diffusion assay, and Staphylococcus aureus (ATCC 8095), Pseudomonas aeruginosa (ATCC10662) and Escherichia coli (ATCC 25922) were found to be the most sensitive against biosynthesized ZnO NPs, whereas the least sensitivity was shown by Bacillus cereus (ATCC 13753). The anti-inflammatory effect was also evaluated for both ZnO NPs and the aqueous leaf extract of P. odoratissimum through the human red blood cells (HRBC) membrane stabilization method (MSM) in vitro models which includes hypotonicity-induced hemolysis. A maximum membrane stabilization of ZnO NPs was found to be 95.6% at a dose of 1000 μg mL−1 compared with the standard indomethacin. The results demonstrated that leaf extract of P. odoratissimum is suitable for synthesizing ZnO NPs, with antioxidant, antibacterial as well as superior anti-inflammatory activity by improving the membrane stability of lysosome cells, which have physiological properties similar to erythrocyte membrane cells and have no hemolytic activity. Overall, this study provides biosynthesized ZnO NPs that can be used as a safe alternative to synthetic substances as well as a potential candidate for antioxidants, antibacterial and anti-inflammatory uses in the biomedical and pharmaceutical industries.

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.

Nanostructured particles offer outstanding diversities of applications in the fields of nanotechnology, nano-engineering, nano-biotechnology, etc. Morphological structure, size distribution, electronic behavior including intrinsic characteristics of nanoparticles depend on the source and synthesis methods. Here, an eco-friendly approach using microwave irradiation for the synthesis of zinc oxide (ZnO) nanoparticles has been reported. Zinc nitrate was used as a precursor whereas starch and D-glucose were used as capping and reducing agent, respectively. The synthesized nanoparticles were characterized by different instrumental methods including Ultraviolet-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and field emission scanning electron microscopy (FE-SEM). The characteristic λmax at 373 nm for ZnO nanoparticles was recorded from UV-Vis absorption spectrum in aqueous system. FT-IR spectrum showed a very sharp peak at 476.62 cm-1 which confirmed the presence of Zn-O bond. The prepared ZnO was highly crystalline having wurtzite structure and the crystallite size was calculated to be 24.41 nm obtained from XRD analysis. FE-SEM images showed that the synthesized ZnO nanoparticles had near- spherical morphology and particle size was found in the range of 40–90 nm. The antibacterial and anti-biofilm application of ZnO nanoparticles were studied and inhibition zones of Gram negative Salmonella typhi (S. typhi), Klebsiella spp., Escherichia coli (E. coli) and Gram positive Staphylococcus aureus (S. aureus)- 8a were found to be 11 mm, 12 mm, 11.5 mm and 13.5 mm, respectively. Besides, ZnO nanoparticles also showed excellent photocatalytic activity against methylene blue dye solution. The easy and eco-friendly fabrication method would play vital role in other nanoparticles synthesis to meet the demand in textile industry, agriculture and medical sectors.

An overview of recent work on the low-temperature plasma-assisted synthesis of zinc oxide (ZnO) nanoparticles is presented and interpreted in terms of gas-phase and surface reactions with illustrated examples. The thermodynamical nonequilibrium conditions allow the formation of chemically reactive species with a potential energy of several eV, which readily interact with the Zn precursors and initiate reactions leading to the formation of nanoparticles or nanowires. The high-quality nanowires were synthesized from Zn powders only upon interaction with moderately ionized plasma in a narrow range of plasma parameters. This technique is promising for the synthesis of large quantities of nanowires with aspect ratios well above 10, but the exact range of parameters remains to be determined. Apart from the ex situ techniques, the ZnO nanoparticles can be synthesized by depositing a film of precursors (often Zn salts or Zn-containing organometallic compounds) and exposing them to oxygen plasma. This technique is useful for the synthesis of well-adherent ZnO nanoparticles on heat-sensitive objects but requires further scientific validation as it often leads to the formation of a semicontinuous ZnO film rather than nanoparticles. Both low-pressure and atmospheric plasmas are useful in converting the precursor film into ZnO nanoparticles despite completely different mechanisms.

Zinc oxide (ZnO) nanoparticles absorb UV light efficiently while remaining transparent in the visible light spectrum rendering them attractive in cosmetics and polymer films. Their broad use, however, raises concerns regarding potential environmental health risks and it has been shown that ZnO nanoparticles can induce significant DNA damage and cytotoxicity. Even though research on ZnO nanoparticle synthesis has made great progress, efforts on developing safer ZnO nanoparticles that maintain their inherent optoelectronic properties while exhibiting minimal toxicity are limited. Here, a safer-by-design concept was pursued by hermetically encapsulating ZnO nanorods in a biologically inert, nanothin amorphous SiO2 coating during their gas-phase synthesis. It is demonstrated that the SiO2 nanothin layer hermetically encapsulates the core ZnO nanorods without altering their optoelectronic properties. Furthermore, the effect of SiO2 on the toxicological profile of the core ZnO nanorods was assessed using the Nano-Cometchip assay by monitoring DNA damage at a cellular level using human lymphoblastoid cells (TK6). Results indicate significantly lower DNA damage (>3 times) for the SiO2-coated ZnO nanorods compared to uncoated ones. Such an industry-relevant, scalable, safer-by-design formulation of nanostructured materials can liberate their employment in nano-enabled products and minimize risks to the environment and human health.

Zinc oxide (ZnO) nanoparticles (NPs) were fabricated by using leaves extracted from the thyme plant by employing a green method. The influence of several calcination (annealing) temperatures on the characteristic properties of fabricated ZnO NPs and the optimum calcination temperature for growing ZnO NPs were studied and reported. The studied calcination temperatures were 150 °C, 250 °C, 350 °C, and 450 °C. Different characterization techniques were used to study and examine the properties of biosynthesized ZnO NPs by using thyme plant leaf extract. The results of each UV-Vis analysis and FTIR spectrum of the leaf extract of the thyme plant confirmed and suggested that the selected leaf extract of thyme is a practicable choice for green synthesis of ZnO NPs. The investigated UV-Vis spectra of plant leaf extract displayed two strong absorption peaks at 266 nm and 313 nm at ambient temperature. The results of FESEM images showed that the calcination temperature has a significant and large effect on the morphology, size, shape, and orientation of ZnO NPs, which have a spherical shape with an average size in the range of 39.4–51.86 nm. In addition, the XRD results confirm that the ZnO NPs formed are pure ZnO with wurtzite hexagonal structure with particle size along the (002) peak in the range of 35.20–243.3 nm. The results of UV-Vis of ZnO NPs displayed a strong peak for all ZnO NPs produced at different calcination temperatures, a high absorbance in the UV region below 400 nm, and a low absorbance rate in the visible range. The obtained energy band gap (Eg) was in the range of 2.645–2.7 eV. In addition, the results of the FTIR spectra of ZnO NPs at different calcination temperatures revealed there was no discernible peak in the monitoring range, which indicated the purity of the ZnO nanoparticles generated via using thyme leaf extract. In addition, from all obtained results of the fabricated ZnO NPs, the ZnO NPs synthesized at the calcination temperature of 450 °C showed a high quality and improvement compared to the ZnO NPs synthesized at other calcination temperatures.

Synthesis of ZnO nanoparticles from zinc acetate dihydrate – An environmental friendly technique

Synthesis and characterization of ZnO nanoparticles for photocatalysis, antibacterial and cytotoxicity in kidney cancer (A498) cell lines

The number of studies on Zinc oxide (ZnO) have increased tremendously over the last ten years due to its widespread applicability as optoelectronic device, sensor, catalyst, transparent conductive oxide layer (TCO) in solar cells and piezoelectric device. The potential compliance of ZnO in those various field is due to its unique properties which exhibit direct wide band gap (∼ 3.37 eV) semiconductor, large exciton binding energy (60 meV), possess good piezoelectric characteristics, chemical stability as well as biocompatibility. At nanometer scale, ZnO nanostructures such as nanorod, nanoneedle, nanobelt and nanoparticles have shown to exhibit different properties from the bulk. Likewise, they demonstrated significance enhancement of ZnO performance due to high surface to volume ratio characteristics. Among the various structures, ZnO nanoparticles offers great extent of applications ranging from chemical sensor, catalyst, anti-bacterial activities, transparent UV protection film, bio-imaging to bio medical application. However, the overall cost of producing these devices is relatively high compared to Si due to high cost of producing ZnO nanoparticles. Realizing of the advance functional device that ZnO nanoparticle is capable of, it is crucial to devise a method to synthesize ZnO nanoparticles for mass production. Up to now, a variety of techniques have been employed for the synthesis of ZnO nanoparticles via physical vapor deposition (PVD) and solution based method. PVD techniques, such as spray pyrolysis, sputter deposition, template assisted growth and chemical vapor deposition requires very complicated equipment, expensive raw materials, high temperature, high pressure and long deposition times which suggest that they are not suitable for large scale production at relatively low cost. In contrast to PVD, solution based techniques such as sol-gel, hydrothermal, sonochemical, microemulsion and precipitation are more feasible to be industrialized as they are low cost and produce high output volume. Comparing both physical and chemical techniques, the latter method is favored in this study. In solution technique, the selection of reactants is crucial as they are involved in the construction and formation of the particles. Most of the reagents employed for synthesizing ZnO nanoparticles are in zinc salt substance which will react with basic solution to provide a medium for nucleation and growth. Zinc salt commonly used are zinc acetate, zinc nitrate, zinc sulphate, and zinc chloride whereas for basic solution; sodium hydroxide, ammonium hydroxide, ammonium carbonate are the reagents that commonly employed. Only a few works that used elementary elements as the reactant in ZnO synthesis have been reported. For example, C. Wang and co-workers have synthesized ZnO nanoparticles using Zn and I 2 which they have discovered that I 2 plays some part in the nucleation of ZnO nanoparticles. However, the role of I 2 in ZnO formation is not thoroughly analyzed and discussed [1]. In this work, we present the study of I 2 role and improvement in ZnO nanoparticles synthesis by introducing Diethanolamine (DEA) as initiator and capping agent as well as O 2 diffusion as catalyst during nanoparticles formation. Moreover, we employed post-heat treatment to removes the byproduct. ZnO nanoparticles properties (structural, morphology and optical) produced under different calcination temperatures at 700, 850 and 1150 °C were characterized using X-ray powder diffractometer (XRD), Scanning electron microscope (SEM) and room temperature Photoluminescence (PL) spectroscopy. Based on the SEM results, uniformly spherical particles are observed for all the samples prepared in the presence of I 2 whereas microsphere with honey comb like structure were observed for samples without the presence of I 2 . Samples heated at 850°C prepared in the I 2 existence shows high intensity of blue-violet emission at 411 nm whereas sample without I 2 exhibit two emission peak centered at 380 nm (UV emission) and 523nm (green emission). Possible reason of the red shifted peak for samples prepared with I 2 with respect to UV may be attributed to zinc interstitial or zinc vacancy defects created via interaction with I 2 during nanoparticles formation. Weight % calculated for samples synthesized with I 2 is ∼ 1.795% whereas without I 2 is ∼ 0.9% indicating enhancement in terms of output volume.

We report the synthesis of zinc oxide (ZnO) nanoparticles and its composite with natural graphite (NG) powder for application in solar cell. ZnO nanoparticles were synthesized using green tea leaf extract as non-toxic and eco-friendly reducing material under microwave irradiation. The formation of ZnO nanoparticles was monitored by the colour changes during the reaction. The synthesized ZnO nanoparticles were characterized by particle size analyzer (dynamic light scattering), scanning electron microscope, UV–visible spectroscopy, atomic force microscope and fluorescence spectroscopy. The average particle size of the ZnO nanoparticles was found to be 26 nm. The synthesized ZnO nanoparticles were further used to prepare ZnO/NG composite material with commercially available NG powder. The current–voltage (I–V) characteristics of thin film of ZnO/NG nanocomposite were investigated. J SC (short-circuit photocurrent), V OC (open-circuit photovoltage), FF (fill factor) and η (efficiency of the solar cell) were measured for ZnO/NG nanocomposite. Interestingly, the cell showed a good power conversion efficiency of 3.54% with high stability.