Properties Of Zinc Oxide Nanoparticles Research Articles

Unlocking the therapeutic potential: Green synthesized zinc oxide/silver nanoparticles from Sophora pachycarpa for anticancer activity, gene expression analysis, and antibacterial applications

Hematologic malignancies and bloodstream infections rank among the most lethal medical conditions. Research on new treatments for these diseases is crucial. In this study, we investigated the anticancer properties and molecular mechanisms of zinc oxide nanoparticles doped with silver synthesized using a green approach involving Sophora pachycarpa (S. pachycarpa) plant seed extract (SPS@ZnO/Ag NPs). Additionally, we explored the antibacterial effects of these nanoparticles and S. pachycarpa extract. The SPS@ZnO/Ag NPs were characterized using XRD, FTIR, zeta potential, EDS, FESEM, and TEM analyses. Subsequently, we assessed the viability of K562 cells in the presence of different nanoparticles and extract. Molecular mechanisms underlying cell death were examined through flow cytometry analysis, Hoechst staining, and relative expression of pro-apoptotic genes (Apaf-1, Cytochrome c, Caspases 3, 6, 9) relative to the gene B-actin. Also, BAX/BCL2 ratio was determined. Antibacterial effects were evaluated against Gram-negative and Gram-positive bacteria. The results confirmed successful synthesis of spherical SPS@ZnO/Ag NPs with positive surface charge, purity, and size ranging from 50 to 65 nm. SPS@ZnO/Ag NPs significantly reduced K562 cell viability compared to S. pachycarpa extract and chemical nanoparticles, with the 1:1 ratio of zinc oxide and silver nitrate exhibiting the highest cell death. The findings from flow cytometry analysis, Hoechst staining, and molecular pathway analysis indicate that SPS@ZnO/Ag NPs induce cancer cell death through apoptosis. Evaluation of antibacterial properties demonstrated the destruction of all studied strains by SPS@ZnO/Ag NPs. Overall, our study demonstrates that green synthesis, in comparison to chemical synthesis, exerts a notable impact on the anticancer properties of zinc oxide nanoparticles doped with silver. Moreover, SPS@ZnO/Ag NPs exhibit targeted induction of cancer cell apoptosis, showcasing their potential application in biomedical fields.

Investigation on the influence of silver doping on structural and biomedical properties of zinc oxide nanoparticles synthesized using crude ethanolic extract of Adiantum venustum D. Don

Investigation on the influence of silver doping on structural and biomedical properties of zinc oxide nanoparticles synthesized using crude ethanolic extract of Adiantum venustum D. Don

Synthesis, characterization, and optoelectronic properties of zinc oxide nanoparticles: A precursor as electron transport layer

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Antibacterial Activity of Prepared Zinc Oxide Nanoparticles by Eco-Friendly Method Using Olive Leaves and Roselle Flower Extracts

This research looked at the antimicrobial properties of zinc oxide nanoparticles (ZnO NPs) made from roselle flower extracts and olive leaves as part of a green synthesis method. We used field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet-visible (UV–vis) spectroscopy and Fourier-transform infrared (FTIR) spectroscopy to study the morphological, structure and optical properties of ZnO NPs. The Field Emission Scanning Electron Microscopy (FESEM) test revealed that the ZnO NPs (Olive leaves) had round particles with sizes ranging from 29.03[Formula: see text]nm to 53.59[Formula: see text]nm, while the ZnO NPs (Roselle flower) had nanoflakes with sizes ranging from 42[Formula: see text]nm to 80[Formula: see text]nm. By using UV–vis spectroscopy, it was found that the optical energy gap for ZnO NPs derived from olive leaves was about 2[Formula: see text]eV and for ZnO NPs derived from rose flowers it was 2.2[Formula: see text]eV. The antimicrobial properties of ZnO nanoparticles (NPs) were assessed against two types of bacteria: gram-negative bacteria (Klebsiella pneumoniae) and gram-positive bacteria Staphylococcus aureus (S. aureus). Both plant extracts exhibited a maximal inhibitory zone of 21[Formula: see text]mm against gram-positive bacteria, specifically S. aureus.

Effect of cobalt and aluminum doping on the structural and magnetic properties of zinc oxide nanoparticles

A systematic study of the substitution effect of Co and Al on ZnO nanoparticles was carried out by x-ray diffraction (XRD) and transmission electron microscopy and using a superconducting quantum interference device magnetometer to study their structural, morphological, and magnetic properties. Zn1−xMxO (M = Co, Al) at different doping concentrations was prepared using a hydrothermal technique. The XRD results with structural Rietveld refinement reveal that the major phase of all samples had a hexagonal wurtzite crystal structure with a P63mc space group. Hysteresis loops with no magnetic saturation at high fields were analyzed at 2 K in all samples. Zero magnetic remanence and zero coercivity were also examined. The results demonstrated that the magnetic ground state at 2 K in all samples was magnetism with the coexistence of antiferromagnetic, ferromagnetic, and superparamagnetic phases. This behavior persisted at 100 and 300 K in the Al-doped sample, while Co-doped ones exhibited a paramagnetic state only. The role of non-magnetic doping, which leads to the appearance of magnetism in ZnO nanoparticles persisting at high temperatures, is discussed herein.

Enhancing dielectric properties of ZnO nanopowders with 2D hBN doping: production, structural, morphological and dielectric characterization

In this study, it was aimed to improve the dielectric properties of ZnO nanoparticles with the addition of hBN, which was not previously available in the literature, and thus to expand their usage areas. Sol–gel synthesis method was used in this study to create pure and hexagonal boron nitride (hBN) doped zinc oxide (ZnO) nanoparticles. Zinc acetate dihydrate Zn(CH3COO)22H2O), sodium hydroxide NaOH, and hexagonal boron nitride (hBN), all from Sigma Aldrich, were used as starting reagents. The reagents were dissolved during the sol–gel synthesis by being heated to 90 °C for 4 h in a magnetic stirrer. FT-IR, XRD, FE-SEM, EDX characterization techniques, and impedance analyzer were used to find functional groups, structural, morphological, and chemical composition, and dielectric properties of the nanoparticles, respectively. The produced un-doped and hBN-doped ZnO particles consist of nano-sized structures. Changes occurred in the intensities and locations of the XRD diffraction peaks and FT-IR peaks with the addition of hBN. Characteristic peaks of both ZnO and hBN were observed in the diffraction peaks of the doped nanoparticles. All nanoparticles were of high purity and were successfully produced by the sol–gel method. It was shown that as the hBN doping level increased, there were more hBN nanoplates in the ZnO matrix, and the EDX results also showed an increase in hBN addition. The frequency stability of the dielectric properties improved after hBN doping. While the dielectric constant at 1 kHz frequency at room temperature is 12.07 in pure ZnO nanoparticles, the increase up to 55.21 is observed in 10% hBN doped nanocomposites. This situation is considered as a great potential for technological applications of this novel nanocomposite material.

Effect of Sintering Time and Cl Doping Concentrations on Structural, Optical, and Luminescence Properties of ZnO Nanoparticles

Zinc oxide (ZnO) nanoparticles were synthesized hydrothermally using zinc acetate dihydrate and sodium thiosulfate pentahydrate precursors. The synthesized powders were sintered in air at 600 °C for different durations with a Cl-doping concentration of 25 mg/g. The optimal sintering time was found to be 5 h, resulting in the successful formation of the ZnO phase with small particle sizes of around 90 nm, nominal atomic fractions of Zn and O (~50%, ~50%), and increased luminescence intensity. The ideal concentration of Cl was discovered to be 25 mg/g of ZnO, which resulted in the highest luminescence intensity. The ZnO luminescence characteristics were observed in emission bands peaking at approximately 503 nm attributed to the transition from oxygen vacancies. A considerable improvement in the emission intensity was observed with increased Cl doping concentration, up to eight orders of magnitude, compared to pristine ZnO nanoparticles. However, the luminescence intensity decreased in samples with higher concentrations of Cl doping due to concentration quenching. These preliminary outcomes suggest that Cl-doped ZnO nanoparticles could be used for radiation detector development for radon monitoring and other related applications.

Theoretical multiscale study on the properties, aqueous solution behavior and biological impact of zinc oxide nanoparticles

The aim of this theoretical study is to describe the relationship between the structure and the physicochemical properties of zinc oxide nanoparticles (ZnO NPs) and Mn doped ZnO NPs to assess their toxicological impact. In order to do so, a multiscale modelling approach is applied. Different nanoparticles, as well as the mechanism(s) of nanoparticle aggregation and growing, are characterized in terms of size and shape considering electronic, surface, structural and topological properties via quantum mechanics simulations. To evaluate the toxicology impact of ZnO NPs in human health safety and their possible environmental impact, classical molecular dynamics simulations were carried out to study the interaction between the nanomaterials and biological target systems: a set of selected human proteins and model plasma membranes. Likewise, the simulation of nanoparticles dispersion in aqueous media along with water adsorption on their surfaces was conducted.The mayor findings may be summarized as: (i) the ZnO NPs from 12 to 96 (ZnO) units are characterized and their interaction energies, HOMO-LUMO gaps, superficial areas and volumes are reported; (ii) the (ZnO)12 NP and Zn11MnO12 NP are further characterized via their topological properties, vibrational spectra, PDOS and non-covalent interactions; (iii) the doping with Mn atoms is favourable. The interaction energies, HOMO-LUMO orbitals and gaps, PDOS, atomic charges, superficial areas and volumes are reported for NPs doped with up to 5 Mn atoms; (iv) high water affinity for ZnO NPs is reported with both quantum and classical calculations, v) (ZnO)12 NPs do not penetrate the cell membrane and (vi) the affinity energy of both ZnO and Mn doped NPs for human proteins is moderate.The reported results provide in-depth whole-chain studies of zinc oxide nanoparticles, which have been successfully applied for different technologies.

Azadirachta indica (AI) leaf extract coated ZnO-AI nanocore–shell particles for enhanced antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA)

With the rise in microbial resistance to traditional antibiotics and disinfectants, there is a pressing need for the development of novel and effective antibacterial agents. Two major approaches being adopted worldwide to overcome antimicrobial resistance are the use of plant leaf extracts and metallic nanoparticles (NPs). However, there are no reports on the antibacterial potential of NPs coated with plant extracts, which may lead to novel ways of treating infections. This study presents an innovative approach to engineer antibacterial NPs by leveraging the inherent antibacterial properties of zinc oxide NPs (ZnO NPs) in combination with Azadirachta indica (AI) leaf extract, resulting in enhanced antibacterial efficacy. ZnO NPs were synthesised by the precipitation method and subsequently coated with AI leaf extract to produce ZnO-AI nanocore–shell structures. The structural and morphological characteristics of the bare and leaf extract coated ZnO NPs were analysed by x-ray diffraction and field emission scanning electron microscopy, respectively. The presence of an AI leaf extract coating on ZnO NPs and subsequent formation of ZnO-AI nanocore–shell structures was verified through Fourier transform infrared spectroscopy and photoluminescence techniques. The antibacterial efficacy of both ZnO NPs and ZnO-AI nanocore–shell particles was evaluated against methicillin-resistant Staphylococcus aureus using a zone of inhibition assay. The results showed an NP concentration-dependent increase in the diameter of the inhibition zone, with ZnO-AI nanocore–shell particles exhibiting superior antibacterial properties, owing to the combined effect of ZnO NPs and the poly phenols present in AI leaf extract. These findings suggest that ZnO-AI nanocore–shell structures hold promise for the development of novel antibacterial creams and hydrogels for various biomedical applications.

Comparative analysis of polyol-synthesized ZnO nanoparticles through first−principles calculations and experimental characterization

An extensive investigation was undertaken to examine the crucial properties of zinc oxide (ZnO) in its hexagonal wurtzite crystal structure, with a focus on its structural, electronic, and optical features. The aim of this study is to examine the correlation between the theoretical and experimental properties of ZnO nanoparticles (NPs). The experimental part involved the fabrication of ZnO NPs through the polyol method, followed by their characterization using X-ray crystallography and UV-Vis absorption spectrophotometry. Computational calculations were conducted using density functional theory (DFT), incorporating the local density approximation (LDA) and the Hubbard-U exchange-correlation (XC) function to enhance the structure of ZnO. The DFT calculations thoroughly matched the experimental observations, including lattice constants and Zn−O bond length. Electronic properties, particularly the band structure, and DOS calculations, further confirmed the experimental findings, especially regarding the band gap energy. Partial density of states (PDOS) analysis provided insights into the role of each atom in the chemical bonding of ZnO, while total density of states (TDOS) analysis evaluated the overall contribution of all atoms. This comprehensive study of the polyol synthesis method for ZnO NPs and the properties derived from the first principles of DFT calculations offers valuable insights for researchers and highlights the potential applications of ZnO in future studies, mainly for optoelectronic applications.

Bio-fabrication, characterization and biological properties of zinc oxide nanoparticles (ZnO-NPs) from scarlet morning glory- Ipomoea hederifolia

Zinc oxide nanoparticles (ZnO-NPs) are a topic of substantial interest for their unique catalytic, magnetic, electrical, optical, and biological properties. It has been noted that plant-mediated synthesis of these nanoparticles has gained attention due to limitations in the chemically synthesized particles, which are also found hazardous to the environment. In the study, the leaf extract of Ipomoea hederifolia L. was utilized to bio-fabricate ZnO-NPs (Ih-ZnO-NPs) and is the earliest to describe the bio-fabrication of ZnO-NPs using the plant and its biological properties. UV–Vis Spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR) were used to elucidate the structural characters of bio-fabricated Ih-ZnO-NPs. The structural characterization studies revealed that Ih-ZnO-NPs are of hexagonal shape, ∼20 nm size and high purity. Aggregation of Ih-ZnO-NPs was noticed under the SEM with a purity of 98 % when analyzed through EDS. The Ih-ZnO-NPs offered significant antibacterial properties with an MIC of 0.312 mg mL−1 for S. aureus and B. subtilis followed by 0.625 mL−1 and 1.25 mg mL−1 for E. coli and S. typhi, respectively. In addition, the antioxidant and antimitotic investigation found that the particles had a dose-dependent activity with an IC50 of 0.94 mg mL−1 and 1.59 mg mL−1, respectively. The results demonstrate that these bio-fabricated ZnO-NPs can be utilized as an alternative to current chemical components after further validation.

Synthesis, characterization, radical scavenging properties of zinc oxide nanoparticles and inhibitory effect of ZnONPs-ciprofloxacin nanoconjugates on multidrug-resistant Staphylococcus aureus (MRSA) enzyme

The study determined the in vitro antioxidant potential of zinc oxide nanoparticles (ZnONPs) and inhibitory properties of ZnONPs-ciprofloxacin nanoconjugate on the activity of dehydrogenase enzyme from multi-drug resistant Staphylococcus aureus (MRSA). Rauwolfia vomitoria (SW) leaf extract was used for the synthesis of the ZnONPs. Volatile phytochemical constituents of the leaf extract were assessed using Gas Chromatography-Mass Spectrometry (GC–MS) which confirmed fifteen volatile phytochemicals with phytol (39.99 %) being the most abundant and the least being 4-hydoxy-3-methylacetophenone (0.85 %). The ZnONPs were characterized with UV–Vis spectroscopy, Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM), and Transmission Electrron Microscopy (TEM). The UV–Vis results showed maximum light absorption at a wavelength of 300 nm whereas EDS revealed 64.84 % Zn, 18.88 % O, and 16.28 % C. The microscopic studies gave agglomerated spherical zinc nanoparticles with average size of 99.02 nm. The free radical scavenging ability showed weaker properties for the ZnONPs compared to the control and the leaf extract. At 30 mg/mL, the nanoconjugates significantly (p < 0.05) recorded 100 % inhibition of the enzyme activities. The inhibitory properties of the antimicrobial agents indicated that ZnONPs-ciprofloxacin > ZnONPs > R. vomitoria leaf extract. The ZnONPs-ciprofloxacin nanoconjugate expressed mild dose–response inhibitory relationship (R2 = 0.66) against the MRSA dehydrogenase activity at the IC50 of 2.93 mg/mL.

Study the Effect of Calendula officinalis Extract Loaded on Zinc Oxide Nanoparticle Cream in Burn Wound Healing.

The skin, the body's largest organ, acts as a protective barrier against pathogens and environmental damage. Skin burns can result from heat, chemicals, friction, or electricity. Nanoscience has recently been utilized to create ointments and creams for burns. Zinc oxide nanoparticles are crucial due to their antimicrobial and antioxidant properties. In this study, a cream containing nanoparticles was loaded with calendula extract, and its ability to promote tissue healing was investigated in Wistar rats with skin burns. The zinc oxide nanoparticles were chemically synthesized and loaded with calendula extract. The morphology and physicochemical properties of the nanoparticles were confirmed by SEM, ZETA size, XRD, and FTIR assays. The MTT technique was employed to assess the cream's impact on fibroblast growth. The antimicrobial activity of the nanoparticles was investigated against Pseudomonas using the MIC method. Real-time PCR was used to determine the expression of the Bax and Bcl-2 genes in aeruginosa. The results showed that zinc oxide nanoparticles at high concentrations increased the proliferation of the fibroblast cells. Histopathological studies showed granulation and epithelialization of the tissue without any hemorrhage or tissue infection during the first days of treatment with this cream. The animal models treated with the cream showed an increase in Bcl-2 gene expression and a decrease in Bax expression. We concluded that zinc oxide nanoparticles loaded with calendula extract have a practical effect in healing burn wounds due to their unique antibacterial properties of zinc oxide nanoparticles and their anti-inflammatory and wound-healing effects. The synergistic effect of these two substances significantly improved the healing process. This newly developed cream can be introduced as a successful and viable treatment option in burn wounds.

Physical Properties of ZnO-NPs Induced by the Thermal Annealing of Hydrozincite Derived from Adansonia Digitata Leaves Extract

In this study, we investigated the effects of the annealing temperatures on the physical properties of zinc oxide nanoparticles produced by the decomposition of the hydrozincite obtained from Adansonia digitata leaves. The results of the X-ray diffraction revealed the formation of well-crystallised hexagonal zinc oxide with an average crystallite size of 11.80 nm, 11.90 nm, 11.97 nm and 15.28 nm for the samples annealed at 400 °C, 500 °C, 600 °C and 700 °C, respectively. The crystallite size of the hydrozincite constituting the unannealed sample was 22 nm. In the spectra of the Fourier transform infrared spectroscopy, the appearance of the peaks at 520 cm-1 for all synthesised materials confirms the formation of pure wurtzite zinc oxide. The band gap determined from diffuse reflectance ultraviolet-visible spectroscopy was found to be 3.19 eV, 3.21 eV, 3.23 eV and 3.24 eV for the samples annealed at 400 °C, 500 °C, 600 °C and 700 °C, respectively. These values increase with the annealing temperature and are still lower than the band gap of pure bulk zinc oxide (3.3 eV) owing to the structural defects as confirmed by the broad emission bands in the visible depicted from the photoluminescence analysis.

Investigation of Impregnation Approach of Zinc Oxide Nano-Dispersions for Potential UV Stabilization in Abies alba and Fagus sylvatica

As biological material, wood is distinctly affected by to various environmental influences during use. Reductions in durability can come from ultraviolet (UV) radiation, insects, fungi, and microorganisms in both exterior and interior applications. Wood can be easily protected from living organisms via the control of moisture content; however, UV radiation is not so easily managed. Wood components subject to this degradation are damaged and decomposed at a molecular level leading to deterioration of surface quality, especially in visible application areas. A potential remedy to this is using the UV-stabilizing properties of zinc oxide nanoparticles. Zinc oxide nano-dispersions based on propylene glycol (PG) were introduced into the microscopic structure of fir (Abies alba) and beech (Fagus sylvatica) wood by whole-cell impregnation to overcome problems associated with surface coatings. In this work the material uptake of ZnO nano-dispersions in concentrations of 1%, 2%, and 3% w/v were investigated and their effect on the stability of the optical appearance to UV exposure in short-term weathering were evaluated. Untreated reference samples showed significant photo-yellowing. A 1% w/v ZnO dispersion significantly increased the UV stability of treated surfaces. It was found that the uptake of the nano-dispersions was independent of the proportion of ZnO, and that the impregnating agents penetrated fir wood (about 200%) stronger than beech wood (about 70%). Already, a 2% w/v ZnO nano-dispersion led to a saturation of ZnO in the cell structure of the treated wood, for fir as well as beech, and no further ZnO uptake was achieved with 3% w/v nano-dispersions. Scanning electron microscopy shows an agglomeration of ZnO-NP in the cellular pathways impacting penetration, reducing leachability at higher concentrations.

Influence of nickel doping and cotton stalk activated carbon loading on structural, optical, and photocatalytic properties of zinc oxide nanoparticles

In the current study, the photodegradation of brilliant green (BG) dye has been studied in relation to the comparative photocatalytic activity of pure ZnO and Ni-doped ZnO/CSAC (cotton stalk activated carbon), which was produced using a chemical precipitation method. The structural, optical, morphological, and functional characteristics of Ni-doped ZnO/CSAC have been investigated. The XRD patterns demonstrated the hexagonal wurtzite structure of the Ni-doped ZnO/CSAC sample. The XPS scan supported a Ni2+ oxidation state for the Ni ions incorporated into the ZnO lattice. The optical features of the Ni-doped and loaded sample demonstrated a red shift in the light absorption and reduced the recombination rate of charge carriers. The FE-SEM was used to examine the morphology of the synthesized all the samples, and EDAX spectroscopy was used to determine their composition. In comparison to pure ZnO, Ni doped, and Ni (0.075 M) doped ZnO/CSAC exhibited a greater photocatalytic degradation of 91.47 % after 120 min under visible light irradiation. This result suggests that Ni-doped ZnO/CSAC may be an effective wastewater treatment material.

Investigation on the impact of cobalt doping on optical, structural and magnetic properties of zinc oxide nanoparticles

In the current article, we investigated the impact of transition metal Co2+ doping in ZnO nanoparticles and its effect on their optical, structural, and magnetic properties. The synthesized nanoparticles have the generic formula Zn1-xCoxO (x = 0.00, 0.03, 0.06, and 0.09). Single-phase hexagonal crystal structure of the synthesized nanopowder was confirmed by x-ray diffractograms. Tauc plots were used to calculate the band gap of all the samples. Multiple emission peaks were observed from the photoluminescence studies. HRTEM was employed to study the particle morphology and the size distribution. X-ray photoelectron (XPS) spectroscopy was performed to investigate the chemical composition of samples. Magnetic measurements were carried out to study the magnetic behaviour of pure and doped ZnO samples. Ferromagnetic behaviour became more prominent with the addition of Co doping, as observed by room temperature M-H plots.

Influence of Copper Doping on Structural and Opto-Electronic Properties of Zinc Oxide Nanoparticles

In this work, we elucidate the opto-electronic properties of pure zinc oxide and copper- doped zinc oxide nanoparticles prepared via the sol-gel method. Here, the main objective is to study the impact of copper doping on the crystalline structure of ZnO and to explore the composition dependent variations in opto-electronic properties. Synthesized ZnO nanoparticles were characterized by SEM, FTIR, UV–vis-nir, and Raman Spectroscopy. The structural and opto-electronic properties are further correlated using UV-vis-nir and high-resolution X- ray diffractometer data analysis. The size of synthesized nanoparticles are found in the range of 9.2 nm to 95.5 nm. Bandgaps are found both in the visible range (2.72 eV – 2.96 eV) as well as in the infrared regions (1.54 eV-1.58 eV). The transmittance of copper doped ZnO nanoparticles increases with increase in the doping concentrations.

Prunus dulcis-mediated zinc oxide nanoparticles: synthesis, characterization, and an evaluation of their biocidal properties

Use of plant extracts for synthesizing zinc oxide (ZnO) nanoparticles is gaining importance due to their easy, eco-friendly, cost effective and non-toxic nature. In this study, an economical biosynthetic approach of ZnO formation was delineated where aqueous extract of Prunus dulcis (almond) leaves has been used as reducing/capping agent followed by their characterization studies. The present study has successfully synthesized pure, highly crystalline in nature, predominantly spherical ZnO nanoparticles within the size range 71–214 nm for nanocystallites and 526 nm-2.37 μm for aggregated flower-shaped ZnO nanoparticles. Microbicidal properties of uncalcined and calcined ZnO nanoparticles were evaluated using test microbes (bacteria: E. coli, S. aureus, P. aeruginosa, B. subtilis; fungi Penicillium spp., F. oxysporum, A. flavus, R. solani). Lack of microbicidal potential was observed against all four bacteria and fungi. When tested for toxicity against HCT-116 carcinoma cells, these nanoparticles displayed non-toxic nature. This biocompatibility is influenced by physico-chemical properties of ZnO nanoparticles as well as biological properties of living cells. Thus, these ZnO nanoparticles can serve as an innocuous machinery in disease therapeutics due to the presence of their non-microbicidal and non-antineoplastic activities.

Synthesis and Characterization of Zinc Oxide Nanoparticles at Different pH Values from Clinopodium vulgare L. and Their Assessment as an Antimicrobial Agent and Biomedical Application.

The current study attempts to evaluate the formation, morphology, and physico-chemical properties of zinc oxide nanoparticles (ZnO NPs) synthesized from Clinopodium vulgare extract at different pH values and to investigate their antimicrobial and biomedical application potential. The reduction of zinc ions to ZnO NPs was determined by UV spectra, which revealed absorption peaks at 390 nm at pH 5 and 348 nm at pH 9, respectively. The spherical morphology of the nanoparticles was observed using scanning electron microscopy (SEM), and the size was 47 nm for pH 5 and 45 nm for pH 9. Fourier-transformed infrared spectroscopy (FTIR) was used to reveal the presence of functional groups on the surface of nanoparticles. The antibacterial activity was examined against Staphylococcus aureus, Streptococcus pyogenes, and Klebsiella pneumonia via the agar-well diffusion method. Comparatively, the highest activities were recorded at pH 9 against all bacterial strains, and among these, biogenic ZnO NPs displayed the maximum inhibition zone (i.e., 20.88 ± 0.79 mm) against S. aureus. ZnO NPs prepared at pH 9 exhibited the highest antifungal activity of 80% at 25 mg/mL and antileishmanial activity of 82% at 400 mg/mL. Altogether, ZnO NPs synthesized at pH 9 show promising antimicrobial potential and could be used for biomedical applications.