Synthesis Of ZnO Nanoparticles Research Articles

Ammonia Sensing Behavior of Green- Synthesized ZnO Nanoparticles Using Optical Density as Sensing Parameter

Ammonia Sensing Behavior of Green- Synthesized ZnO Nanoparticles Using Optical Density as Sensing Parameter

Eco-friendly approach for the synthesis of zinc oxide nanoparticles (ZnO NPs) using Verbena officinalis L: enhancement of photocatalytic activity under UV light and application of response surface methodology

Eco-friendly approach for the synthesis of zinc oxide nanoparticles (ZnO NPs) using Verbena officinalis L: enhancement of photocatalytic activity under UV light and application of response surface methodology

Green synthesis of zinc oxide nanoparticles using Albizia procera leaf extract: Degradation of methylene blue dye via Advanced Oxidation Process and Box–Behnken Design

Green synthesis of zinc oxide nanoparticles using Albizia procera leaf extract: Degradation of methylene blue dye via Advanced Oxidation Process and Box–Behnken Design

An Eco-friendly Approach to ZnO NP Synthesis Using Citrus reticulata Blanco Peel/Extract: Characterization and Antibacterial and Photocatalytic Activity.

Emission of greenhouse gases and infectious diseases caused by improper agro-waste disposal has gained significant attention in recent years. To overcome these hurdles, agro-waste can be valorized into valuable bioactive compounds that act as reducing or stabilizing agents in the synthesis of nanomaterials. Herein, we report a simple circular approach using Citrus reticulata Blanco (C. reticulata) waste (peel powder/aqueous extract) as green reducing and capping/stabilizing agents and Zn nitrate/acetate precursors to synthesize ZnO nanoparticles (NPs) with efficient antimicrobial and photocatalytic activities. The obtained NPs crystallized in a hexagonal wurtzite structure and differed clearly in their morphology. UV-vis analysis of the nanoparticles showed a characteristic broad absorption band between 330 and 414 nm belonging to ZnO NPs. Fourier transform infrared (FTIR) spectroscopy of ZnO NPs exhibited a Zn-O band close to 450 cm-1. The band gap values were in the range of 2.84-3.14 eV depending on the precursor and agent used. The crystallite size obtained from size-strain plots from measured XRD patterns was between 7 and 26 nm, with strain between 16 and 4%. The highly crystalline nature of obtained ZnO NPs was confirmed by clear ring diffraction patterns and d-spacing values of the observed lattice fringes. ZnNPeelMan_400 and ZnNExtrMan showed good stability, as the zeta potential was found to be around -20 mV, and reduced particle aggregation. Photoluminescence analysis revealed different defects belonging to oxygen vacancies (VO+ and VO+2) and zinc interstitial (Zni) sites. The presence of oxygen vacancies on the surface of ZnAcExtrMan_400 and ZnAcPeelMan_400 increased antimicrobial activity, specifically against Gram-negative bacteria Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis). ZnNExtrMan with a minimal inhibitory concentration of 0.156 mg/mL was more effective against Gram-positive bacteria Staphylococcus aureus (S. aureus), revealing a high influence of particle size and shape on antimicrobial activity. In addition, the photocatalytic activity of the ZnO NPs was examined by assessing the degradation of acid green dye in an aqueous solution under UV light irradiation. ZnAcPeelMan_400 exhibited excellent photocatalytic activity (94%) within 90 min after irradiation compared to other obtained ZnO NPs.

A novel sonoelectrochemical approach for preparing of ZnO nanoparticles

A novel, rapid, and facile method for one-step sonoelectrochemical synthesis of zinc oxide nanoparticles (UEZ) was introduced in this study. The optimum operating parameters have been selected at a voltage of 7.5 V, KCl concentration of 0.5 M, and the reaction time of 60 min. The as-prepared UEZ were characterized by XRD, SEM, and HRTEM. It was found that the UEZ has a hexagonal wurtzite structure with high crystalline quality, good purity, a size range of 30–100 nm, and good photocatalytic degradation of methylene blue. This work provides a facile route for large-scale synthesizing ZnO nanoparticles via anodization.

Biosynthesis and antibacterial activity of ZnO nanoparticles using Buchanania obovata fruit extract and the eutectic-based ionic liquid

The fruit extract of Buchanania obovata and the eutectic-based ionic liquid were utilized, in an eco-friendly, inexpensive, simple method, for synthesizing zinc oxide nanoparticles (ZnO NPs). The influence of the reducing, capping and stabilizing agents, in both mediums, on the structure, optical, and morphological properties of ZnO NPs was extensively investigated. The surface plasmon resonance peaks were observed at 340 nm and 320 nm for the fruit-based and the eutectic-based ionic liquid mediums, respectively, indicating the formation of ZnO NPs. XRD results confirmed the wurtzite structure of the ZnO NPs, exhibiting hexagonal phases in the diffraction patterns. The SEM and TEM images display that the biosynthesized ZnO NPs exhibit crystalline and hexagonal shape, with an average size of 40 nm for the fruit-based and 25 nm for the eutectic-based ionic liquid. The Brunauer–Emmett–Teller (BET) surface area analysis, revealed a value ∼13 m2 g−1 for ZnO NPs synthesized using the fruit extract and ∼29 m2 g−1 for those synthesized using the eutectic-based ionic liquid. The antibacterial activity of the biosynthesized ZnO NPs was assessed against clinically isolated Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains using the inhibition zone method. The ZnO NPs produced from the eutectic-based ionic liquids confirmed superior antibacterial activity against both S. aureus and E. coli compared to those mediated by the utilized fruit extract. At a concentration of 1000, the eutectic-based ionic liquid mediated ZnO NPs displayed a maximum inhibition zone of 16 mm against S. aureus, while against E. coli, a maximum inhibition zone of 15 mm was observed using the fruit extract mediated ZnO NPs. The results of this study showed that the biosynthesized ZnO NPs can be utilized as an efficient substitute to the frequently used chemical drugs and covering drug resistance matters resulted from continual usage of chemical drugs by users.

Synergistic bifunctionality of ZnO nanowalls: Antibacterial activity and photocatalysis through integrated in silico and in vitro approaches

This research investigation delves into the versatile attributes of ZnO nanowalls, specifically probing into their dual functionality encompassing antibacterial and photocatalytic properties. The synthesis of ZnO was achieved by employing a microwave-mediated co-precipitation technique. The resulting sample underwent thorough characterization through diverse analytical methodologies. X-ray diffraction analysis disclosed the prevalence of the hexagonal wurtzite phase, as confirmed by JCPDS card No. 36–1451, with an average crystallite size determined as 23.48 nm. Tauc plot extrapolation method was applied to the UV absorption spectrum to ascertain the bandgap energy. The ZnO nanostructure morphology, featuring multi-directional nano-walls, was unveiled through scanning electron microscopy (SEM). The BET nitrogen adsorption technique quantified the surface area of the ZnO sample as 6.69 m2/g. In antibacterial evaluation, the in vitro (disk diffusion) method showcased the remarkable efficacy of ZnO against both gram-positive Staphylococcus sp. and gram-negative E. coli bacteria. Complementing these experimental findings, in silico molecular docking studies exposed both nano ZnO ligands with standard and corrected lattice parameter values exhibiting favorable binding energy. Moreover, the synthesized ZnO nanoparticles exhibited remarkable photocatalytic activity, particularly demonstrated in the decolorisation of Azure A and Azure B dyes, following the first-order Langmuir–Hinshelwood kinetic model. The collective findings underscored a synergistic effect within the fabricated ZnO nanoparticles, showcasing their dual prowess in both antibacterial and photocatalytic activities. The observed phenomenon can be chiefly ascribed to the presence of lattice strain and dislocation density. This intriguing dual functionality positions them as promising candidates for potential applications in wastewater treatment.

Psidium guajava-mediated green synthesis of Fe-doped ZnO and Co-doped ZnO nanoparticles: a comprehensive study on characterization and biological applications.

The efficacy of nanoparticles (NPs) in healthcare applications hinges on their biocidal activity and biocompatibility. This research is dedicated to green-synthesized NPs with potent biocidal properties, aiming for high inhibition rates in bacterial infections and offering a multifunctional application, including potential use in anticancer therapy, in comparison to traditional antibiotics. The present study focuses on synthesis of zinc oxide (ZnO) nanoparticles (NPs), including iron-doped ZnO (GZF) and cobalt-doped ZnO (GZC), using the green co-precipitation method involving Psidium guajava (P. guajava) leaf extract. The physicochemical properties of the synthesized NPs were analyzed using various characterization techniques. The antibacterial and anticancer activity depends on the generation of reactive oxygen species (ROS), particle size, surface area, oxygen vacancy, Zn2+ release, and diffusion ability. The antibacterial activity of the synthesized NPs was tested against various Gram-positive (Streptococcus pneumoniae (S. pneumoniae), Bacillus subtilis (B. subtilis) and Gram-negative (Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) bacterial strains. The zone of inhibition showed higher activity of GZC (18-20mm) compared to GZF (16-19mm) and GZO (11-15mm) NPs. Moreover, anticancer studies against blood cancer cell line (MOLT-4) showed half-maximal inhibitory concentration of 11.3μg/mL for GZC compared to GZF and GZO NPs with 12.1μg/mL and 12.5μg/mL, respectively. Cytotoxicity assessments carried out on the fibroblast L929 cell line indicated that GZO, GZF, and GZC NPs demonstrated cell viabilities of 85.43%, 86.66%, and 88.14%, respectively. Thus, green-synthesized GZC NPs hold promise as multifunctional agents in the biomedical sector.

Photocatalytic degradation of organic dyes in water using semiconductor ZnO nanoparticles synthesized using Crataegus mexicana extract

In this work, the synthesis of zinc oxide (ZnO) nanoparticles was made using an eco-friendly methodology with a natural extract. The fruit of tejocote (Crataegus mexicana) was used as a stabilizing agent for synthesizing zinc oxide nanoparticles (NPs). Once the NPs were obtained, diverse characterization techniques were used to determine the physicochemical and optical properties of the ZnO NPs; the ultraviolet–visible spectroscopy was used to determine the uv absorption spectra of ZnO NPs and the bandgap of the material, the FT-IR spectrum of the ZnO NPs shows the presence of the Zn–O bond at 560 cm−1, XRD results show that the ZnO NPs exhibit a hexagonal crystal structure zincite type, the SEM confirms slight agglomerations between nanoparticles, Also from TEM results, the nanoparticles present a quasi-spherical morphology with sizes ranging from 18.25 nm to 36.88 nm, indicating an influence of the concentration of the Crataegus mexicana extract in the synthesis process of ZnO NPs. Photoluminescence spectroscopy of ZnO NPs shows strong emission bands in the visible spectrum around 425 nm, 467 nm, and 492 nm, and weak emission bands in the UV spectrum were observed. Finally, a photocatalytic study was realized for the photodegradation of 5 pollutant dyes: methylene blue (MB), malachite green (MG), congo red (CR), rhodamine b (RB), and methyl orange (MO). The results show degradation of the organic dyes after 180 min by a photodegradation process where ZnO nanoparticles act as a photocatalyst, indicating that the synthesized ZnO nanoparticles have excellent photocatalytic properties.

Biogenic Zinc Oxide Nanoparticles: An Insight into the Advancements in Antimicrobial Resistance

Abstract Multidrug resistance (MDR) is a significant global challenge requiring strategic solutions to address bacterial infections. Recent advancements in nanotechnology, particularly in the synthesis of zinc oxide nanoparticles (ZnO NPs) using natural agents as stabilizers and reducing agents, have shown promising results in combating MDR. These nanoparticles possess strong antimicrobial properties against different strains of Gram-positive and Gram-negative, making them suitable for various industries, including food, pharmaceuticals, coatings, and medical devices. ZnO-NPs work by generating reactive oxygen species, releasing zinc ions (Zn2+), disrupting the bacterial cell membrane, interfering with metabolic processes and genetic material, and inducing oxidative stress and apoptosis. However, more research is needed to refine synthesis techniques, control size and morphology, and increase antibacterial efficacy. To fully understand their potential, interactions with proteins, DNA, and bacterial cell walls must also be examined. Investigating the synergistic potential of biogenic ZnO NPs with conventional antibacterial treatments could enhance therapeutic effectiveness while minimizing the risk of resistance emergence. Here we provide insight into the advancements in biogenic synthesis of nanoparticles using bio extracts and their applications in antimicrobial resistance as well as various factors affecting the synthesis process and characterization techniques for ZnO NPs. Recent studies on the antimicrobial activity of biogenic ZnO NPs against different pathogens and their mechanisms of action are discussed. Furthermore, potential applications of biogenic ZnO NPs as antimicrobial agents are highlighted

Effect of Oxidizing Agent on the Synthesis of ZnO Nanoparticles for Inverted Phosphorescent Organic Light-Emitting Devices without Multiple Interlayers.

Inverted organic light-emitting devices (OLEDs) have been aggressively developed because of their superiorities such as their high stability, low driving voltage, and low drop of brightness in display applications. The injection of electrons is a critical issue in inverted OLEDs because the ITO cathode has an overly high work function in injecting electrons into the emission layer from the cathode. We synthesized hexagonal wurtzite ZnO nanoparticles using different oxidizing agents for an efficient injection of electrons in the inverted OLEDs. Potassium hydroxide (KOH) and tetramethylammonium hydroxide pentahydrate (TMAH) were used as oxidizing agents for synthesizing ZnO nanoparticles. The band gap, surface defects, surface morphology, surface roughness, and electrical resistivity of the nanoparticles were investigated. The inverted devices with phosphorescent molecules were prepared using the synthesized nanoparticles. The inverted devices with ZnO nanoparticles using TMAH exhibited a lower driving voltage, lower leakage current, and higher maximum external quantum efficiency. The devices with TMAH-based ZnO nanoparticles exhibited the maximum external quantum efficiency of 19.1%.

Photocatalytic and antibacterial activity of green synthesized and immobilized zinc oxide nanoparticles for the removal of sulfadiazine and acetaminophen: Effect of operational parameters and degradation pathway

The present research investigates the photocatalytic degradation of pharmaceutical compounds acetaminophen (ATP) and sulfadiazine (SFZ), using zinc oxide nanoparticles synthesized by green method (N-ZnO). The nanoparticles were synthesized from the extract of neem leaf (Azadirachta indica) and were characterized using spectroscopic techniques. The effect of operational parameters like pH, light intensity, catalyst dosage and initial concentration was also studied. The degradation pathway of ATP and SFZ was analyzed using LCMS. Since the recovery and reuse of nanoparticles from water is difficult, the ZnO nanoparticles were immobilized by coating onto activated carbon generated from spent tea waste (TAC). At optimum conditions, 100% removal of ATP and SFZ was observed using ZnO nanoparticles coated on spend tea leaf activated carbon (N ZnO@TAC). The antibacterial studies of N-ZnO, TAC and N-ZnO@TAC revealed that N-ZnO nanoparticles exhibited more antibacterial properties when compared to the other two. Hence green synthesized ZnO nanoparticles are found to exhibit excellent antibacterial and photocatalytic properties for the removal of emerging contaminants.

Synthesize Iron Oxide and Zinc Oxide Nanoparticles Using Plant Extracts

Recently, a plant-mediated approach to synthesizing nanoparticles via unconventional, eco-friendly technique-based techniques involving natural materials was developed. In this work, the microwave method has been used, where Hibiscus rosa sinensis flower extract and Myristica Fragrans have been used as reducers and stabilizers to synthesize iron oxide nanoparticles (α-Fe2O3) and zinc oxide nanoparticles (ZnO), respectively. The melting point and ultraviolet-visible spectrometer (UV-Vis) have been utilized to investigated and characterized the synthesized iron oxide and Zinc oxide nanoparticles. The results showed that the melting point of Fe2O3-NPs and ZnO-NPs were above ~300 °C, which indicated the melting of nanoparticle. Nanoparticles exhibit a significant in melting point as their size goes below ≈10 nm. in addition, the UV-Vis absorption spectra of the synthesized iron oxide NPS show peak surface plasmon resonance (SPR) band around 320 nm and Zinc oxide NPS shown peak surface plasmon resonance (SPR) band around 370 nm. The microwave method has been successfully used in this study, which has advantages over the other methods.

Heavy metals removal from synthetic and industrial wastewater using synthesized zinc oxide nanoparticles

With the advancement in wastewater treatment systems over conventional systems the application of nanotechnology has gained popularity in the past decade. The process can be applied by modifying the physico-chemical properties of metal oxides that increase their effectiveness in extracting heavy metals from wastewater. The present study has been carried out by synthesizing the Zinc oxide nanoparticles using green and chemical synthetic methods. Green-synthesized ZnO nanoparticles (GS-ZnO-NP) were discovered to exhibit a maximum removal effectiveness of 93% and 94% for heavy metals in industrial wastewater and synthetic wastewater, respectively. However, heavy metals removal efficiency from industrial and synthetic wastewater was observed to be 98% and 98% respectively using chemically synthesized ZnO nanoparticles (CS-ZnO-NP). The heavy metals removal efficiency for specific metal is observed to be Cr > Pb > Cu > Hg > As. The kinetics of adsorption was calculated using Freundlich and Langmuir isotherm models. Freundlich model is the best fit with the coefficient of correlation in the range of 0.71–1 for green synthesized and 0.82 to 0.95 for chemically synthesized ZnO nanoparticles.

Phytogenic-Mediated Zinc Oxide Nanoparticles Using the Seed Extract of Citrullus lanatus and Its Integrated Potency against Multidrug Resistant Bacteria.

In the current research study, zinc oxide nanoparticles (ZnO-NPs) were synthesized via a green synthesis technique using the seed extract of Citrullus lanatus. The study further intended to evaluate the potential synergistic effects of ZnO-NPs with antibiotics against multidrug resistant (MDR) bacteria. It was observed that C. lanatus seed extracts obtained by n-hexane and methanolic solvents revealed the presence of constituents, such as tannins, flavonoids, and terpenoids. Furthermore, the extract of n-hexane displayed the strongest antibacterial activity against Yersinia species (17 ± 1.2 mm) and Escherichia coli (17 ± 2.6 mm), while the methanolic extract showed the maximum antibacterial activity against E. coli (17 ± 0.8 mm). Additionally, the ZnO-NP synthesis was confirmed by ultraviolet-visible analysis with a characteristic absorption peak at 280 nm. The Fourier transform infrared spectroscopy analysis suggested the absorption peaks in the 500-3800 cm-1 range, which corresponds to various groups of tertiary alcohol, aldehyde, amine, ester, aromatic compounds, thiol, amine salt, and primary amine. The scanning electron microscopy spectra of ZnO-NPs demonstrated the presence of zero-dimensional spherical particles with well-dispersed character. Moreover, encapsulation with ZnO-NPs improved the antimicrobial activity of antibiotics against the panel of MDR bacteria, and the increases in the effectiveness of particular antibiotics against MDR bacteria were significant (P = 0.0005). In essence, the synthesized ZnO-NPs have the potential as drug carriers with powerful bactericidal properties that work against MDR bacterial strains. These outcomes are an indication of such significance in pharmaceutical science, giving possibilities for further research and development in this field.

Green Chemical Approach for the Synthesis of ZnO Nanoparticles and Investigation of their Cytotoxicity

AbstractIn this study, zinc oxide nanoparticles (ZnO‐NPs) are synthesized and combined with chitosan (Cs) to create Cs/ZnO‐NPs nanomicelles, aiming to investigate their potential as a novel cancer treatment. The ZnO‐NPs are produced through a sintering process at temperatures ranging from 300 to 700 °C. The most effective nanoparticles are obtained at 600 °C, as determined by X‐ray diffraction (XRD) and Fourier‐transform infrared spectroscopy (FTIR) analyses, which confirmed their crystallinity and purity. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are employed to characterize the size and shape of the nanoparticles, revealing predominantly spherical and hexagonal structures with stable dimensions. The cytotoxic effects of the Cs/ZnO‐NPs are evaluated against various cancer cell types. The results show that at a concentration of 125 µg mL−1, the Cs/ZnO‐NPs demonstrate significantly higher cancer cell toxicity compared to ZnO‐NPs alone, while remaining non‐toxic to normal cells. This indicates that Cs/ZnO‐NPs have a superior ability to selectively target cancer cells. These findings suggest that Cs/ZnO‐NPs nanomicelles hold promise as an effective and safe nanotherapeutic approach in the realm of cancer treatment, meriting further exploration for clinical applications.

Effect of acidic and basic leachants on the synthesis of ZnO nanoparticles from Egyptian zinc ore, their optical/surface characteristics and photocatalytic performance

It is of pivotal significance to optimize the parameters affecting the extraction of metals from natural ores to convert them to value-added products. Owing to their semiconducting nature, most metal oxides, including ZnO, have various electronic, optical, and photocatalytic applications. Hence, we are investigating the leaching of Zn from Smithsonite (an Egyptian ore) using acidic/basic leaching agents (leachants). The leached salts were employed in a co-precipitation method followed by calcination to obtain crystalline ZnO nanoparticles. Both photocatalytic performance of the ZnO nanoparticles obtained from acid leaching and basic leaching were investigated toward the photodegradation of Rhodamine B dye. The ZnO(A) prepared using the acid leaching route has achieved about 5.6-fold enhancement in the dye photodegradation% and 5.3-fold enhancement in the observed rate constant compared to ZnO(B) prepared from basic leaching. Finally, the superior photocatalytic activity of the ZnO(A) is attributed to the smaller particle size, larger surface area, and existence of some defects that enhanced the photocatalytic performance.

A Study on the Antibacterial, Antispasmodic, Antipyretic, and Anti-Inflammatory Activity of ZnO Nanoparticles Using Leaf Extract from Jasminum sambac (L. Aiton).

The green synthesis of zinc oxide nanoparticles (ZnO NPs) using plants has grown in significance in recent years. ZnO NPs were synthesized in this work via a chemical precipitation method with Jasminum sambac (JS) leaf extract serving as a capping agent. These NPs were characterized using UV-vis spectroscopy, FT-IR, XRD, SEM, TEM, TGA, and DTA. The results from UV-vis and FT-IR confirmed the band gap energies (3.37 eV and 3.50 eV) and the presence of the following functional groups: CN, OH, C=O, and NH. A spherical structure and an average grain size of 26 nm were confirmed via XRD. The size and surface morphology of the ZnO NPs were confirmed through the use of SEM analysis. According to the TEM images, the ZnO NPs had an average mean size of 26 nm and were spherical in shape. The TGA curve indicated that the weight loss starts at 100 °C, rising to 900 °C, as a result of the evaporation of water molecules. An exothermic peak was seen during the DTA analysis at 480 °C. Effective antibacterial activity was found at 7.32 ± 0.44 mm in Gram-positive bacteria (S. aureus) and at 15.54 ± 0.031 mm in Gram-negative (E. coli) bacteria against the ZnO NPs. Antispasmodic activity: the 0.3 mL/mL sample solution demonstrated significant reductions in stimulant effects induced by histamine (at a concentration of 1 µg/mL) by (78.19%), acetylcholine (at a concentration of 1 µM) by (67.57%), and nicotine (at a concentration of 2 µg/mL) by (84.35%). The antipyretic activity was identified using the specific Shodhan vidhi method, and their anti-inflammatory properties were effectively evaluated with a denaturation test. A 0.3 mL/mL sample solution demonstrated significant reductions in stimulant effects induced by histamine (at a concentration of 1 µg/mL) by 78.19%, acetylcholine (at a concentration of 1 µM) by 67.57%, and nicotine (at a concentration of 2 µg/mL) by 84.35%. These results underscore the sample solution's potential as an effective therapeutic agent, showcasing its notable antispasmodic activity. Among the administered doses, the 150 mg/kg sample dose exhibited the most potent antipyretic effects. The anti-inflammatory activity of the synthesized NPs showed a remarkable inhibition percentage of (97.14 ± 0.005) at higher concentrations (250 µg/mL). Furthermore, a cytotoxic effect was noted when the biologically synthesized ZnO NPs were introduced to treated cells.

Catharanthus roseus-assisted bio-fabricated zinc oxide nanoparticles for promising antibacterial potential against Klebsiella pneumoniae.

This study emphasized on the synthesis of zinc oxide nanoparticles (ZnO NPs) in an environmentally friendly manner from the extract of Catharanthus roseus leaves and its antibacterial assessment against the pneumonia-causing pathogen Klebsiella pneumoniae. This simple and convenient phytosynthesis approach is found to be beneficial over conventional methods, wherein plants serve as excellent reducing, capping, and stabilizing agents that enables the formation of ZnO NPs without the use of harmful chemicals. The formation of ZnO NPs was confirmed through several characterization techniques such as UV-visible spectroscopy, XRD, FT-IR, SEM, HR-TEM, and EDX. XRD analysis revealed high polycrystallinity with crystallite size of approximately 13nm. SEM and HR-TEM revealed the hexagonal structure of ZnO NPs with the particle size range of 20-50nm. The EDX shows the elemental purity without any impurity. Furthermore, the antibacterial efficacy by the technique of disc diffusion exhibited clear inhibition zones in ZnO NPs-treated discs. In addition, 125µg/mL of ZnO NP concentration showed minimum inhibition by the microbroth dilution method. The potent inhibitory activity was further validated with trypan blue dye exclusion and fluorescence microscopy. Finally, SEM examination confirmed the efficient antibacterial potential of ZnO NPs through disruption of the intact morphology of Klebsiella pneumoniae.

Evaluation of the antimicrobial activity and chickpea growth stimulation effects of green synthesized zinc oxide nanoparticles

Green synthesized nanoparticles are believed to alleviate the detrimental effects of chemical fertilizers and the multidrug resistance of various microbial strains. This study evaluates the use of bush tea-mediated zinc oxide nanoparticles (ZnO NPs) for chickpea fertilization and assesses their cytotoxicity, antioxidant and antibacterial activity. The study demonstrated that the application of ZnO NPs improved the number of leaves, nodules, biomass and yield of chickpea cultivars under glasshouse conditions. The authors suggest that biosynthesized ZnO NPs are a good plant growth stimulant. The control with no nanoparticles application, had higher values of photosynthetic rate and water use efficiency in the Desi genotype whereas for the Kabuli genotype, 25 mg/L showed higher values of stomatal conductance and transpiration efficiency, while 15 mg/L gave the highest water use efficiency and photosynthetic rate. Furthermore, the inhibitory activities of bacteria were reported in which E. coli and S. aureus were the most sensitive bacterial strains. The ZnO NPs also quenched free radicals that demonstrate antioxidant activity. Thus, they can be beneficial to both plants and humans as they reduce oxidative stress that can cause diseases. Furthermore, toxicity to cells was evaluated and ZnO NPs were less toxic to the studied cells with IC50 values of 16.17 µg/mL and 21.30 µg/mL against lung cancer and embryonic cell lines. Thus, the use of ZnO nanoparticles with antimicrobial activity could help fight against several diseases attacking humans and plants.