Formation Of ZnO NPs Research Articles

Biosynthesis of Zinc Oxide Nanoparticles Using Garlic Peel Extract and Their Antibacterial Potential

Zinc oxide nanoparticles (ZnO NPs) have gathered interest because of their unique characteristics and potential applications. In the current work, ZnO NPs underwent an eco-friendly biosynthesis process using garlic peel extract. The biosynthesized ZnO NPs were characterized using different analyses including Ultraviolet-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR). The produced ZnO NPs exhibited a UV–vis spectrum absorption peak at 365 nm, thus indicating the formation of ZnO NPs. The SEM showed that the biosynthesized ZnO NPs had an irregular surface morphological shape with an average size of 17 nm, according to the DLS analysis. Based on the FTIR findings, the bioactive functional groups responsible for stabilizing and capping the ZnO-NPs were confirmed. The biosynthesized ZnO NPs exhibited 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and antimicrobial activities against Gram-positive (Bacillus cereus) and Gram-negative bacteria (Klebsiella pneumonia). Therefore, the plant-mediated biosynthesized ZnNPs can be considered a promising candidate as an antioxidant and antimicrobial agent against pathogenic microbes found in different areas such as food safety and agriculture. Through the utilization of bioinformatics, we identified six potential targets for drug development in K. pneumonia and B. cereus, along with their corresponding interacting residues with zinc oxide nanoparticles. Additionally, our research revealed that the zinc oxide nanoparticles exhibited binding capabilities with the sulfiredoxin domain located at the specific targets of K. pneumonia, a crucial mechanism responsible for the repair of bacterial cells under oxidative stress.

Sustainable synthesis of zinc oxide nanoparticles using Piper betle petiole leaf extract: Antibacterial, antioxidant, and cytotoxic potential

The present study used Piper betle petiole leaf extract as an efficient reducing agent to produce zinc oxide nanoparticles (ZnO NPs). The change in the color of reaction mixture from brown to white indicates the formation of ZnO NPs, which is also noticed in UV–Visible spectral analysis (peak at 320 nm). Investigations using X-ray diffraction (XRD) revealed that the particles were crystalline. Additionally, scanning electron microscopy (SEM), Energy Dispersive X-ray diffraction (EDAX), dynamic light scattering (DLS), and Fourier transform infrared (FTIR) techniques were used to understand the structural, and elemental aspects of the as-prepared ZnO NPs. The antibacterial activity of ZnO NPs was assessed using the disc diffusion approach method against clinical strains of Escherichia coli, Pseudomonas fluorescence, Micrococcus luteus, and Bacillus subtilis. The zone of inhibition and minimum inhibitory indices (MIC) were used in this process. The as-prepared ZnO NPs showed strong antibacterial effects. In addition, the anticancer efficacy of the material was tested against MDA-MB-231 breast cancer cell lines, the results of which revealed that the tested ZnO NPs was potent in inhibiting the growth of the cancer cells. The mechanistic evaluation of such an activity carried out using in silico methods suggested that the anti-breast cancer activity of L-ZnONPs was mediated by human HER2 kinase domain. This suggests that preparation of ZnO NPs from plant sources can be an excellent method of producing biomedical goods that are both environmentally friendly and versatile.

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.

Green Synthesis of Zinc Oxide Nanoparticles Using Clove Oil Extract (Syzygium aromaticum) and Evaluate their Antibacterial Activity against MRSA

There is a crucial need for the development of effective antimicrobial agents due to the rising incidence of hospital-acquired bacterial infections caused by multidrug-resistant microbes, leading to significant mortality and morbidity worldwide. Therefore, the current study aimed to synthesize zinc oxide nanoparticles (SaZnONPs) using clove extract through an environmentally friendly technique and to investigate their antibacterial activity against MRSA (Staphylococcus aureus). Clove extract acts as both a capping and reducing agent in the formation of ZnO-NPs. The formation of SaZnONPs was confirmed using various analytical techniques. Initially, clove extract was incubated with a zinc nitrate solution, and the subsequent change in color of the solution indicated the reduction of zinc nitrate ions to ZnO nanoparticles. UV-visible spectroscopy revealed a surface plasmon resonance band of SaZnONPs at 329.26 nm. Additionally, SEM imaging indicated that the nanoparticles had an average size of 41 nm and exhibited a spherical shape. The antibacterial activity of SaZnONPs was evaluated against MRSA using agar well diffusion and minimum inhibitory concentration assays. The phytochemicals present in clove extract facilitated the synthesis of stable ZnO-NPs, demonstrating promising antibacterial properties.

The advance anticancer role of polymeric core-shell ZnO nanoparticles containing oxaliplatin in colorectal cancer.

We evaluated the activity of core-shell ZnO nanoparticles (ZnO-NPs@polymer shell) containing Oxaliplatin via polymerization through in vitro studies and in vivo mouse models of colorectal cancer. ZnO NPs were synthesized in situ when the polymerization step was completed by co-precipitation. Gadolinium coordinated-ZnONPs@polymer shell (ZnO-Gd NPs@polymer shell) was synthesized by exploiting Gd's oxophilicity (III). The biophysical properties of the NPs were studied using powder X-ray diffraction (PXRD), Fourier transforms infrared spectroscopy, Ultraviolet-visible spectroscopy (UV-Vis), field emission electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy, dynamic light scattering, and z-potential. (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) was used to determine the antiproliferative activity of ZnO-Gd-OXA. Moreover, a xenograft mouse model of colon cancer was exerted to survey its antitumor activity and effect on tumor growth. In the following, the model was also evaluated by histological staining (H-E; Hematoxylin & Eosin and trichrome staining) and gene expression analyses through the application of RT-PCR/ELISA, which included biochemical evaluation (MDA, thiols, SOD, CAT). The formation of ZnO NPs, which contained a crystallite size of 16.8 nm, was confirmed by the outcomes of the PXRD analysis. The Plate-like morphology and presence of Pt were obtained in EDX outcomes. TEM analysis displayed the attained ZnO NPs in a spherical shape and a diameter of 33 ± 8.5 nm, while the hydrodynamic sizes indicated that the particles were highly aggregated. The biological results demonstrated that ZnO-Gd-OXA inhibited tumor growth by inducing reactive oxygen species and inhibiting fibrosis, warranting further research on this novel colorectalcancer treatment agent.

Fabrication and characterization of curcumin loaded ZnO nanoparticles and their in vitro antibacterial activity

Nanotechnology is broadly defined as the study and development of the chemical physical and natural properties of materials, devices, and structures that differ from those found on a larger scale, and Nano patents are derived from the Japanese language. Zinc oxide nanoparticles are used in a wide-ranging applications, visible light, catalytic actions, ultrasonic, deodorizing, diabetes treatment, cosmetics, lasers, paints, ultraviolet light absorbing constituents, rubber industry, catalytic agent for light flattening, and specifically in the medical and pharmaceutical sciences7. Curcumin is a useful plant-based material derived from "turmeric" that has the potential to be used in the green synthesis of ZnONPs. This is due to the influence of "polyphenol," which may also result in the formation of ZnONPs during the reduction process. Characterization reported Spherical particles with varying size from few nanometers to about 900 nm. The antibacterial activity by disk diffusion method against E. coli (Gram negative), Pseudomonas aerugionsa, Bordetella bronchiseptics & Micrococcus luteus revealed mark able zone of inhibition that declared potent antibacterial activity of Curcumin ZnO NP against gram positive bacteria more than negative ones where Ciprofloxacin was used as standard.

Digera muricata (L.) Mart. mediated synthesis of antimicrobial and enzymatic inhibitory zinc oxide bionanoparticles

Abstract Herein, we report a simple and ecofriendly synthesis of ZnO nanoparticles (ZnO NPs) employing Digera muricata along with bioassay studies of synthesized NPs. The ZnO NPs obtained were indicated by a colour change from yellow to almost faint yellow giving whitish tinge and supported by the appearance of UV-Vis band at 373 nm and were characterized by using Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray (EDX), and scanning electron microscopy (SEM). The FT-IR spectrum confirmed the presence of biomolecules fabricated on ZnO NPs as indicated by the absorption bands at 1,378 for C–O cm−1, and ZnO NPs were also evident from the absorption bands at 440 and 670 cm−1, the former being the result of symmetric vibration of hexagonal ZnO and the latter belonged to a very weak vibration of ZnO. Its surface morphology was confirmed by SEM, and the zinc and oxygen bonds were confirmed by EDX analysis giving sharp signals for Zn and oxygen with At% of 17.58 and 30.49, respectively. The antimicrobial activity of ZnO nanoparticles was determined by the agar well diffusion method against pathogenic bacterial and fungal strains using imipenem and miconazole as standards. The results reflected that ZnO NPs enhanced the activity of plant extracts against all employed algal (E. coli, S. faecalis, P. aeruginosa, K. pneumonia, S. aureus, and B. subtilis) and fungal (T. mentogrophytes, E. floccosum, A. niger, M. canis, and F. culmorum) strains. The antibacterial and antifungal activities of extracts were enhanced by the formation of ZnO NPs. The results indicated that Digera muricata extract contains effective reducing agents for green synthesis of Digera muricata fabricated ZnO NPs, which are more potent antimicrobial than the plant extract and showed almost similar inhibition against lipoxygenase, i.e., the IC50 value of 83.82 ± 1.15, comparable to the standard.

Abatement of organic and inorganic pollutants from drinking water by using commercial and laboratory-synthesized zinc oxide nanoparticles

ZnO nanoparticles have been synthesized and applied for the removal of different environmental pollutants in the present study. Combustion method is used for the preparation of ZnO NPs. X-Ray diffraction pattern reveals the crystallinity of the nanoparticles, where SEM and TEM images displayed that ZnO NPs were of size less than 100 nm and nearly spherical in shape. UV–Vis and IR spectra revealed the formation of ZnO NPs. Adsorption and advanced oxidation processes were employed for the removal/degradation of trace elements/pesticide. UV reactor containing 1 UV rod of 11 W (Philips) was used for the photocatalytic degradation of pesticide. ICP–OES and GC–MS techniques were used for the further quantitative analysis of trace elements and OP pesticide—monocrotophos, respectively. The analysis shows the 88% degradation of monocrotophos when subjected to UV light in the reaction chamber for 120 min at a pH 4 when 2 g of nanocatalyst is applied. However, the removal of trace element Arsenic shows linear adsorption as compared to Cd and Se. The removal efficiency of ZnO nanoparticles for Cd and Se was 36% and 64%, respectively, after 120 min. The synthesized nanoparticles are more effective than the commercially available ones.

A novel synthesis of zinc oxide nanoparticles using various carbohydrate sources and its antimicrobial effects

In the present study, ZnONPs were synthesized using various carbohydrates sources such as maltose, dextrose, and fructose extract for the first time by precipitation method. The various carbohydrates sources act as efficient, reducing as well as stabilizing agents. The biologically synthesized Zinc oxide nanoparticles were characterized by Scanning Electron Microscope (SEM), UV–visible spectrophotometer (UV), Fourier Transmission Infrared Spectra (FTIR), X-Ray Diffraction (XRD), Zeta Potential and Particle Size analysis. The UV results indicated the formation of ZnONPs around 200–400 nm. FTIR studies showed the presence of various functional groups responsible for the synthesis of ZnONPs. Morphological analysis using SEM revealed the spherical and cube-shaped structures of the ZnONPs. XRD analysis revealed the high crystalline nature of the synthesized nanomaterials. Zeta potential showed the high stability of the nanomaterials synthesized. In order to determine the antimicrobial activity, the synthesized ZnONPs were treated against gram-positive and gram-negative bacteria such as Staphylococcus epidermidis and Enterobacter aerogenes, and the results showed high activity of ZnONPs synthesized from fructose. The study highlighted the high antimicrobial activity of biologically synthesized ZnONPs.

Using Oven Microwave for Synthesis ZnO Nps using Sargassum sp. and Padina sp. Extract

An oven microwave was established for synthesis of zinc oxide nanoparticles using Sargassum sp. and Padina sp. extract and 0.1 M ZnCl2 solution as a precursor. The ZnO nanoparticles had been characterized such as chemical structure by Fourier transform infrared (FTIR) spectroscopy, particle size distribution with Particle Size Analyzer (PSA), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEMEDS) and crystalline properties with X-ray diffraction (XRD). The result showed that FTIR spectra revealed the involvement of hydroxyl groups and sulfate polysaccharide in the formation of ZnO NPs and protein was involved in stabilizing. PSA analysis showed that the size ranged of ZnO NPs extract Sargassum sp. synthesized 351,14 and 1.336.19 nm for extract Padina sp. The particle size distribution was homogeneous but their size hadn’t met the size of nanometers. The range of %mass elements Zn and O ZnO extract Sargassum sp. and Padina sp. synthesized didn’t approach standard ZnO. The crystallinity properties showed only ZnO extract of Padina sp. synthesized which had a peak with an angle value of 2θ was almost equal to standard ZnO and after confirmed to Match program! 3 crystal structure ZnO synthesized wasn’t imperfect hexagonal wurtzite. Ovens microwave could be used to synthesize ZnO from Padina sp. extract but it was still necessary to develop a method so that ZnO could be obtained with nanoparticle size and ideal hexagonal wurtzit structure.

Catalytic Effect of Photoluminescent Zinc Oxide Nanoparticles Formed in the Presence of Quaternary Ammonium Salts.

The comparative effect of two quaternary ammonium salts from 1,2-bis(4-pyridyl)ethane (PyQAs), namely N,N′-diphenacyl-1,2-bis(4-pyridinium)ethane dibromide (PyQAs1) and N,N′-di(p-methoxyphenacyl)-1,2-bis(4-pyridinium)ethane dibromide (PyQAs2), upon the size and photoluminescence of zinc oxide nanoparticles (ZnO NPs) was investigated. The formation of ZnO NPs took place in the presence of variable amounts of the two PyQAs species (1, 2.5, and 5%), according to the chemical precipitation of zinc(II) acetate with potassium hydroxide in ethanol under reflux. The obtained ZnO NPs were structurally characterized by means of X-ray powder diffraction, infrared, and Raman spectroscopy. The fluorescence of all supernatant solutions, observed under ultraviolet light, determined us to make an investigation of the solutions by means of liquid chromatography coupled with electrospray ionization mass spectrometry (LC-MS-ESI) in order to elucidate the identity of the newly formed fluorescent species. Such an occurrence thus allowed the invocation of the catalytic effect of zinc(II) ions towards the organic transformation of both nonfluorescent PyQAs surfactants into new fluorescent organic species.

A POTENT CYTOTOXICITY AND ANTIMICROBIAL ACTIVITY OF ZINC OXIDE NANOPARTICLES SYNTHESIZED BY LEAF OF IPOMOEA PES-CAPRAE (L.) R. BR.

Objective: The present study was conducted to investigate the cytotoxicity and antimicrobial activity of zinc oxide nanoparticles (ZnO NPs) synthesized as eco-friendly technique from the leaf extract of Ipomoea pes-caprae (L.) R. Br. against human lung adenocarcinoma (A549), brain tumor (U87) cells, and human pathogens Salmonella typhi, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, and Bacillus subtilis.
 Materials and Methods: The work was carried out with varying precursor (plant extract) volume to optimize the synthesis of ZnO NPs and it was confirmed by ultraviolet (UV)-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, scanning electron microscopy, and atomic force microscope (AFM) characterization techniques and evaluate its cytotoxicity activity by 3-(4,5-dimethyl-2- thiazolyl)-2,5-diphenyl--tetrazolium bromide assay method, antimicrobial activity by disk diffusion method.
 Results: A peak at 320 nm with maximum intensity was observed at temperature of 80°C with pH of 8.0 in UV-visible spectroscopy confirmed the formation of ZnO NPs and we calculate the size of ZnO NPs from XRD data found as 15.8 nm. The FTIR analysis evaluated that the presence of different functional groups is carboxyl, amine, and phenolic compounds of leaves extract which are involved in the reduction of zinc ions and acts as capping the ZnO NPs. AFM microgram confirms that ZnO NPs were in nanorange and spherical in nature. The cytotoxicity activity of A549 and U87 cell lines treated with various concentrations of ZnO NPs showed a dose-dependent increase in cell inhibition and the half maximal inhibitory concentration value was calculated to be 7.8 μg/ml. The antibacterial activity of selected pathogens shows higher zone of inhibition.
 Conclusion: The present study reveals that synthesized ZnO NPs capping with various bioactive compounds present in the leaf of I. pes-caprae show promising activity of cancer cell lines and antimicrobial agents; hence, further detailed study may lead to develop at a novel phytomedicine for the anticancer and antimicrobial drugs.

In-situ fabrication of ZnO thin film electrode using spent Zn–C battery and its electrochemical performance for supercapacitance

In consideration of effective supercapacitors which are also affordable and lightweight, metal oxides can be considered because of the higher charge storage capability. This work establishes the in situ fabrication of a supercapacitor electrode, employing spent Zn–C batteries as precursor. Every year, extensive number of waste batteries including Zn–C battery end up in landfill, which prolonged the compulsion of waste disposal in landfill and creates environmental and health threat. The transformation of waste battery materials into fabricating components for energy applications, is of great significance for sustainable strategies but it is a challenging work to produce nanomaterials with purity by green methods. The present study proposes the in situ fabrication of ZnO NPs as ultra-thin film on a porous silicon (P-Si) substrate from spent Zn–C battery at 900 °C in the horizontal tube furnace under argon atmosphere. The particles were around 45 nm size and semi-spherical in morphology and showed uniform distributions all over the substrate as a discrete ultra-thin film. The ZnO ultra-thin film basically comprised of several ZnO film layer which stacked with each other periodically and made one thin layer of ~ 390 nm, where the single layer was ~ 45 nm. Formation of ZnO NPs were detected by the analysis of XRD, EDS and XPS. Using cyclic voltammetry as well as impedance spectroscopy in 0.6 M KOH as electrolyte, electrochemical properties of developed electrodes and supercapacitor have also been examined. The ZnO/P-Si electrode demonstrated a highest value of specific capacitance 547 F g−1 at 5 mV s−1 scan rate. Obtained results demonstrate that spent Zn–C battery can be selected to fabricate the energy storage devices which can offer economical, technological and environmental advantages.

Photocatalytic degradation of methylene blue using biosynthesized zinc oxide nanoparticles from bark extract of Kalopanax septemlobus

In this study, we applied Kalopanax septemlobus-ZnO nanoparticles (Ks-ZnO NPs) with green approach one-pot synthesis. Further, the extracts were used as capping agent and Zn (OAc)2 as the metal precursor to synthesize ZnO nanoparticles. The formation of ZnO NPs, the surface plasmon resonance were observed at 372 nm in UV–vis spectroscopy. The presence of functional groups which as a capping agent and formation of ZnO nanoparticles were confirmed in Fourier Transform Infrared Spectroscopy (FTIR) result. The crystallization, elemental mapping and morphology showed by X-ray diffraction (XRD), Field-Emission Transmission Electron Microscopy (FE-TEM), and Energy dispersive X-ray spectroscopy (EDX) respectively. The photocatalytic activity of Ks-ZnO nanoparticles, was determined using methylene blue dye degradation percentage under UV light irradiation (365 nm), which resulted rate constant (k) was found 0.1215 with 97.5% of degradation in 30 min. In summary, phytochemicals in K. septemlobus extract have a potential as a reducing agent to form Ks-ZnO nanoparticles. The Ks-ZnO NPs are capable to degrade Methylene blue in brief time due to its extract-capped zinc oxide nanoparticles. Accordingly, the use of K. septemlobus for biosynthesis of nanoparticles may have an advance for many applications as a cost-effective and eco-friendly photocatalyst.

Biosynthesis, characterization, and antibacterial activity of zinc oxide nanoparticles derived from Bauhinia tomentosa leaf extract

A facile, eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) employing Bauhinia tomentosa leaf extract as bioreducing agent was reported. The green-synthesized ZnO NPs were characterized by UV–Vis, TEM, EDX, XRD, and FTIR analyses. The formation of ZnO NPs was confirmed by the appearance of characteristic SPR peak at 370 nm due to the collective oscillation of electrons in the conduction band in UV–Vis spectra. The hexagonal morphology exhibiting nanosized ZnO was observed from the TEM and XRD analyses. The chemical bonds present in the as-synthesized ZnO NPs were identified by FTIR analysis. ZnO NPs showed a significant antibacterial activity against Gram-negative bacteria P. aeruginosa and E. coli than Gram-positive bacteria. Results of this study demonstrated that B. tomentosa leaf extract containing phytochemicals such as alkaloids, terpenoids, flavonoids, tannins, carbohydrates, and sterols possess bioreducing property for ZnO synthesis and the obtained ZnO NPs could be employed effectively as a better bactericidal agent for biological applications.Graphical abstract

Preparation of Zinc Oxide Nanoparticles‐Based Starch Paste and its Antifungal Performance as a Paper Adhesive

Zinc oxide nanoparticles (ZnO NPs) are used as antifungal agents and imparted in starch paste. The zinc oxide nanoparticles are synthesized using starch as a stabilizing agent under sonochemical irradiation, and then used in the preparation of ZnO NPs‐based starch paste. The effects of starch and ultrasonic irradiation on the formation of ZnO NPs are subsequently investigated. Characterization by X‐ray diffraction and transmission electron microscopy reveals that ZnO NPs synthesized under an optimal condition are highly dispersed and well‐defined crystals with diameters of approximately 5 nm. The antifungal performance of ZnO NPs‐based starch paste is evaluated under a high temperature and humidity environment, and is compared with traditional fungicides, alum, and pure terephthalic acid (PTA). In addition, the paste shows negligible toxicity and deterioration to the mechanical properties of the mounted paper. Lastly, the paper mounted with ZnO NPs‐based starch paste shows superior antifungal performance, an essential property protecting paper documents from mold growth, compared to pristine starch paste.

Synthesis and characterization of zinc oxide nanoparticles using tuber extract of anchote (Coccinia abyssinica (Lam.) Cong.) for antimicrobial and antioxidant activity assessment

Coccinia abyssinica (C. abyssinica) tuber extract assisted biosynthesized Zinc oxide nanoparticles (ZnO Nps) were characterized using UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Blue shift of absorptional peak to 365 nm indicated formation of ZnO Nps. X-ray diffraction showed well defined peak characteristic of the Nps. FESEM and TEM image revealed the synthesized nanoparticles has a hexagonal shape and the average particle size was 10.4 nm. The antimicrobial activities of the synthesized ZnO Nps were tested using well diffusion assay and Staphylococcus aureus (MTCC-3160) was found to be the most sensitive against synthesized ZnO Nps whereas, least sensitivity was exhibited by Salmonella typhimurium (MTCC-1251).Free radical scavenging capacity of ZnO Nps were assessed using 2,2–diphenyl-1-picrylhydrazylhydrate (DPPH) assay, with varying ZnO Nps concentration, which showed scavenging activity with IC50 = 127.74 μg /mL.

Synergistic Antimicrobial and Cytotoxic Potential of Zinc Oxide Nanoparticles Synthesized Using Cassia auriculata Leaf Extract

The problem of microbial resistance is growing, and search for novel approaches to tackle the problem on multidrug resistance pathogens is the need of the hour. The present investigation involves green synthesis of zinc oxide nanoparticles (ZnO NPs) using Cassia auriculata leaf extract and evaluates its synergistic antimicrobial and cytotoxic effect. The results of various techniques confirmed the formation of ZnO NPs. UV-visible spectrum of ZnO NPs showed maximum peak at 370 nm. The crystalline nature of the ZnO NPs was confirmed by XRD analysis. The SEM analysis revealed that particles were spherical and irregular in shape, and average size of nanoparticles was 68.64 nm. The antimicrobial activity and synergistic antimicrobial activity were evaluated against pathogenic microorganisms. ZnO NPs showed broad spectrum of antimicrobial activity against tested pathogens and enhanced synergistic antimicrobial activity as compared to standard antibiotic. Cytotoxic effect of ZnO NPs was evaluated by MTT assay against HeLa cancer cell line, and ZnO NPs showed dose-dependent cytotoxic activity. The synthesized ZnO NPs possess significant antimicrobial and cytotoxic activity and hence can be used therapeutically as nanomedicine for diagnosis and drug therapy.

Novel synthesis and structural analysis of zinc oxide nanoparticles for the non enzymatic glucose biosensor

A non-enzymatic glucose biosensor was developed by utilizing the zinc oxide nanoparticles (ZnO NPs) synthesized by a novel green method using the leaf extract of Ocimum tenuiflorum. The structural, optical and morphological properties of ZnO NPs characterized by means of X-ray diffraction (XRD), ultraviolet-visible (UV–vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDAX) spectroscopy, and transmission electron microscopy (TEM). The XRD analysis revealed that the ZnO NPs were crystalline and had a hexagonal wurtzite structure. The crystallite size measured by XRD was the same as that measured using SEM and TEM. The UV–vis absorption spectrum estimates the band gap of ZnO NPs present in the range of 2.82 to 3.45eV. The reduction and formation of ZnO NPs mainly due to the involvement of leaf extract bio-molecular compounds analyzed from the FTIR spectra. The SEM result confirms the morphology of the NPs responsible from the various concentration of leaf extract in the synthesis process. HRTEM analysis depicts the spherical structure of ZnO NPs. The synthesized NPs have the average size ranges from 10 to 20nm. The fabricated GCE/ZnO glucose sensor represents superior electro catalytic activity that has been observed for ZnO NPs with a reproducible sensitivity of 631.30μAmM−1cm−2, correlation coefficient of R=0.998, linear dynamic range from 1–8.6mM, low detection limit of 0.043μM (S/N=3) and response time<4s.

Sargassum wightii-synthesized ZnO nanoparticles reduce the fitness and reproduction of the malaria vector Anopheles stephensi and cotton bollworm Helicoverpa armigera

Helicoverpa armigera Hubner is an important polyphagous agricultural insect pest, highly mobile, with a worldwide distribution. In India, it causes substantial losses to cotton, legumes, cereal and vegetable crops. Malaria is caused by parasites from the genus Plasmodium that are transmitted by female anopheline mosquitoes. Anopheles stephensi Liston is the leading vector of malaria in India, parts of Asia and the Middle East. In this research, we investigated the efficacy of green-synthesized zinc oxide nanoparticles (ZnO NPs) fabricated using the brown macroalga Sargassum wightii Greville ex J.Agardh. The formation of ZnO NPs was confirmed by surface Plasmon resonance band illustrated in UV–vis spectrophotometry. ZnO NP were characterized by XRD, SEM, EDX and FTIR analyses. Low doses of S. wightii extract and ZnO NP showed larvicidal and pupicidal toxicity on A. stephensi and H. armigera. LC50 of ZnO NP ranged from 4.330 (larva I) to 7.430 ppm (pupa) for An. stephensi, and from 12.278 (larva I) to 20.798 ppm (pupa) for H. armigera. Both S. wightii extract and ZnO NP strongly reduced longevity and fecundity of An. stephensi and H. armigera. In food utilization experiments, the S. wightii extract and ZnO NP reduced food consumption of H. armigera individuals. Nutritional indices declined significantly, while the larval approximate digestibility was significantly higher post-treatment with 25 ppm of ZnO NP and 250 ppm of S. wightii extract. Concerning non-target effects, in standard laboratory conditions the predation efficiency of guppy Poecilia reticulata was 66.28% and 55.36% against I and II instar larvae of An. stephensi, respectively. In a ZnO NP-contaminated environment, fish predation was boosted to 86.75% and 74.12%, respectively. Overall, the current approach adopted here contributes to control and adaptively manage resistance to other available insecticides in field populations of H. armigera and An. stephensi.