M. Maaza

In vitro cytotoxicity effect and antibacterial performance of human lung epithelial cells A549 activity of Zinc oxide doped TiO2 nanocrystals: Investigation of bio-medical application by chemical method

We report the synthesis of high quality ZnO doped TiO2 nanocrystals by chemical method at room temperature (RT), it can cause serious oxidative stress and DNA damage to human lung epithelial cells (A549) lines. Our aim in this study, to reduce the cytotoxicity effect of ZnO doped TiO2 nanocrystals are widely in biological fields. Several studies have been performed to understand the influence of ZnO doped titanium dioxide (TiO2-NPs) on cell function; however the effects of nanoparticle against to exposure on the cell membrane have been duly addressed fascinatingly so far. However, In this interaction, which may alter cell metabolism and integrity, it is one of the importance to understand the modifications of the cell membrane, mechanisms of pulmonary A549 cell lines nanoparticles were uptake and the molecular pathway during the initial cell responses are still unclear and much more investigative efforts are need to properly characterize the ZnO doped titanium dioxide nanoparticles were reported successfully. In particular of the epithelial cells, upon particles are exposed human pulmonary epithelial cells (A549) to various concentrations of composition, structure and morphology of the nanocrystals were analyzed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). XRD assessed the crystal structure of the nanocrystals which identified peaks associated with (002), (100) and (101) planes of hexagonal wurtzite-type ZnO with lattice constants of a=b=3.249Å and c=5.219Å. The IR results showed high purity of products and indicated that the nanocrystals are made up of TiO and ZnO bonds. The Photoluminescence (PL) spectra are dominated by a strong narrow band edge emission tunable in the blue region of the visible spectra indicating a narrow size distribution of ZnO/TiO2 nanocrystals which exhibits antibacterial activity over a broad range of bacterial species and in particular against Stre. Mut where it out competes four other commonly used E.coli, Pse. Aug, Stre. Mut and Salm. sps, well as testing four different appropriate concentration from the results showed a significant gain in viable cell numbers of all four bacteria species, with 5mM and 10mM being the most effective and 2mM being the worst, where it provided an effective improvement from the growth mechanism has been also proposed to the current interest of these nanocrystals will discussed in detail.

Elucidation of photocatalysis, photoluminescence and antibacterial studies of ZnO thin films by spin coating method

The ZnO thin films have been prepared by spin coating followed by annealing at different temperatures like 300°C, 350°C, 400°C, 450°C, 500°C & 550°C and ZnO nanoparticles have been used for photocatalytic and antibacterial applications. The morphological investigation and phase analysis of synthesized thin films well characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence (PL), Transmission Electron Microscopy (TEM) and Raman studies. The luminescence peaks detected in the noticeable region between 350nm to 550nm for all synthesized nanosamples are associated to the existence of defects of oxygen sites. The luminescence emission bands are observed at 487nm (blue emission), and 530nm (green emission) at the RT. It is observed that there are no modification positions of PL peaks in all ZnO nanoparticles. In the current attempt, the synthesized ZnO particles have been used photocatalytic and antibacterial applications. The antibacterial activity of characterized samples was regulated using different concentrations of synthesized ZnO particles (100μg/ml, 200μg/ml, 300μg/ml, 400μg/ml, 500μg/ml and 600μg/ml) against gram positive and gram negative bacteria (S. pnemoniae, S. aureus, E. coli and E. hermannii) using agar well diffusion assay. The increase in concentration, decrease in zone of inhibition. The prepared ZnO morphologies showed photocatalytic activity under the sunlight enhancing the degradation rate of Rhodamine-B (RhB), which is one of the common water pollutant released by textile and paper industries.

Antiproliferative effects on human lung cell lines A549 activity of cadmium selenide nanoparticles extracted from cytotoxic effects: Investigation of bio-electronic application

Cadmium selenide (CdSe) nanoparticles make necessary to acquire more information against the cytotoxic effects on human lung epithelial cells A549 potential adverse to health effects. More biological studies highlighted their cytotoxic potential like pulmonary or respiratory diseases were focused on toxicity nanoparticles mechanisms are involved. The aim of our research, is the comparison of cytotoxicity effect between cells-particle interactions, viability test, membrane integrity and oxidative stress were investigated. XRD showed a strong peak associated with (111) plane of hexagonal CdSe suggesting formation of highly orientated nanoparticles. The longitudinal optical phonon shifted slightly due to strain whereas strong low-energy shoulder shift can be explained within a model for surface optical phonons. Photocatalytic activity of CdSe nanoparticles were investigated by exploiting photocatalytic degradation of Rhodamine B (RhB). The typical UV-vis absorption spectra of RhB solution at different time intervals it can be clearly seen that the relative intensity of the absorption peak corresponding to RhB, with the catalyst for different concentration time intervals (0mM, 2mM, 5mM & 10mM) of the prepared CdSe nanoparticles. After completion of 5mM % the dye was completely degraded and the absorption spectra act as a photocatalyst. CdSe nanoparticles exhibits antibacterial activity over a broad range of bacterial species and in particular against P. vulgaris where it out competes four other commonly used S. aureus, E.coli, P. vulgaris and E. hermannii, well as testing four different appropriate concentration from the results showed a significant gain in viable cell numbers of all four bacteria species, with 5mM and 10mM being the most effective and 2mM being the worst, where it provided only a slight improvement from the control in detail.

Photocatalytic degradation effect of malachite green and catalytic hydrogenation by UV–illuminated CeO2/CdO multilayered nanoplatelet arrays: Investigation of antifungal and antimicrobial activities

CeO2/CdO multi-layered nanoplatelet arrays have been synthesized by sol-gel method at two different temperatures using Citrus limonum fruit extract and the effect of particle size on the photocatalytic performance is studied. The particle size and phases was analysed by X-ray diffraction pattern (XRD) which brought out the formation of cubic phase in the synthesized samples. Field Emission Scanning electron microscopy (FESEM) revealed the surface morphology and made up of cumulative form of platelet shaped arrays with an average size of 10nm. The elemental composition and the purity of the nanomaterials were confirmed by Energy Dispersive X-ray spectroscopy (EDX). CeO2/CdO multilayered binary metal oxide nanoplatelet arrays were formed which was further explored with Fourier transform infrared spectroscopy (FTIR), it reveals that the nanocomposites contain CeO and CdO bonds. Determination of the direct and indirect bandgap energy of the nanoplatelet arrays was carried out by UV-Vis-DRS studies. In MG degradation, both the hole (h+) and hydroxyl radical (OH) played a major role than the superoxide radical (O2-). Possible photo degradation mechanisms are proposed and discussed in this article. CeO2/CdO multi-layered nanoplatelet arrays showed antibacterial activity and among the tested ones, it showed better growth inhibition towards P. aeruginosa MTCC73. Thus, this greener synthetic procedure was a highly effective method due to low-cost, highly effective UV light responsive material for environmental safety.

Punicalagin Green Functionalized Cu/Cu2O/ZnO/CuO Nanocomposite for Potential Electrochemical Transducer and Catalyst

A novel ternary Punica granatum L-Cu/Cu2O/CuO/ZnO nanocomposite was successfully synthesised via green route. In this work, we demonstrate that the green synthesis of metal oxides is more viable and facile compare to other methods, i.e., physical and chemical routes while presenting a potential electrode for energy applications. The prepared nanocomposite was characterised by both microscopic and spectroscopic techniques. High-resolution scanning electron microscopy (HRSEM) and X-ray diffraction (XRD) techniques revealed different transitional phases with an average nanocrystallite size of 29–20xa0mm. It was observed that the nanocomposites changed from amorphous-slightly crystalline Cu/Cu2O to polycrystalline Cu/Cu2O/CuO/ZnO at different calcination temperatures (room temperature-RT- 600xa0°C). The Cu/Cu2O/ZnO/CuO metal oxides proved to be highly crystalline and showed irregularly distributed particles with different sizes. Meanwhile, Fourier transform infrared (FTIR) spectroscopy confirmed the purity while together with ultraviolet-visible (UV-Vis) spectroscopy proved the proposed mechanism of the synthesised nanocomposite. UV-Vis showed improved catalytic activity of the prepared metal oxides, evident by narrow band gap energy. The redox and electrochemical properties of the prepared nanocomposite were achieved by cyclic voltammetry (CV), electrochemical impedance (EIS) and galvanostatic charge-discharge (GCD). The maximum specific capacitance (Cs) was calculated to be 241xa0Fxa0g−1 at 50xa0mVxa0s−1 for Cu/Cu2O/CuO/ZnO nanoplatelets structured electrode. Moreover, all the CuO nanostructures reveal better power performance, excellent rate as well as long term cycling stability. Such a study will encourages a new design for a wide spectrum of materials for smart electronic device applications.

Synthesis and analytical applications of photoluminescent carbon nanosheet by exfoliation of graphite oxide without purification

We report synthesis and structural, chemical and optical properties of graphene nanosheet prepared by facile method. The surface morphology of the graphene nanosheet was revealed using AFM studies. Raman fingerprints for single-bilayer, and few-layer graphene reflect changes in the electronic structure and electron–phonon interactions and allow unambiguous, high throughput, identification of graphene layers. Strong blue shifts were absorbed in the PL spectra that attributed to the quantum confinement effect. FTIR and, XPS results confirm the formation of carbon sheets. The topological features, structural, optical properties of single sheet were closely match with predictions of first principles atomistic modeling. Furthermore facile method of material synthesis described in this article can be used to fabricate innovative 2D nanocrystalline materials with unique properties for broad range of applications.

Well-Aligned Graphene Oxide Nanosheets Decorated with Zinc Oxide Nanocrystals for High Performance Photocatalytic Application

Graphene oxide (GO) nanosheets modified with zinc oxide nanocrystals were achieved by a green wet-chemical approach. As-obtained products were characterized by XRD, Raman spectra, XPS, HR-TEM, EDS, PL and Photocatalytic studies. XRD studies indicate that the GO nanosheet have the same crystal structure found in hexagonal form of ZnO. The enhanced Raman spectrum of 2D bands confirmed formation of single layer graphene oxides. The gradual photocatalytic reduction of the GO nanosheet in the GO:ZnO suspension of ethanol was studied by using X-ray photoelectron (XPS) spectroscopy. The nanoscale structures were observed and confirmed using high resolution transmission electron microscopy (HR-TEM). The evolution of the elemental composition, especially the various numbers of layers were determined from energy dispersive X-ray spectra (EDS). PL properties of GO:ZnO nanosheet were found to be dependent on the growth condition and the resultant morphology revealed that GO nanosheet were highly transparent in the visible region. The photocatalytic performance of GO:ZnO nanocomposites was performed under UV irradiation. Therefore, the ZnO nanocrystals in the GO:ZnO composite could be applied in gradual chemical reduction and consequently tuning the electrical conductivity of the graphene oxide nanosheet.

Synthesis of silver nanoparticles (Ag NPs) for anticancer activities (MCF 7 breast and A549 lung cell lines) of the crude extract of Syzygium aromaticum

In the present report, silver nanoparticles were synthesized using Piper nigrum extract for in vitro cytotoxicity efficacy against MCF-7 and HEP-2 cells. The silver nanoparticles (AgNPs) were formed within 20min and after preliminarily confirmation by UV-Visible spectroscopy (strong peak observed at ~441nm), they were characterized by using FT-IR and HR-TEM. The TEM images show spherical shape of biosynthesized AgNPs with particle size in the range 5-40nm while as compositional analysis were observed by EDAX. MTT assays were carried out for cytotoxicity of various concentrations of biosynthesized silver nanoparticles and Piper nigrum extract ranging from 10 to 100μg. The biosynthesized silver nanoparticles showed a significant anticancer activity against both MCF-7 and Hep-2 cells compared to Piper nigrum extract which was dose dependent. Our study thus revealed an excellent application of greenly synthesized silver nanoparticles using Piper nigrum. The study further suggested the potential therapeutic use of these nanoparticles in cancer study.

Green synthesis of Co3O4 nanoparticles via Aspalathus linearis: Physical properties

ABSTRACT This study reports on the bio-synthesis and the main physical properties of p-type Co3O4 nanoparticles for the first time by a completely green chemistry process using Aspalathus lineariss natural extract as an effective chelating agent. Their surface/interface and optical properties are reported. In addition to the X-ray diffraction investigations, the Raman, and infrared as well as X-ray photoelectron spectroscopies confirmed the single phase of the Co3O4 nanoparticles. As their average size can be as low as ⟨φparticle⟩ ∼3.6u2005nm, the reticular atomic plans are under a slight compressive state.

Structural, Optical, Morphological and Microbial Studies on SnO2 Nanoparticles Prepared by Co-Precipitation Method

Nanoparticles of tin oxide (SnO2) powders were prepared by co-precipitation method at 500 °C, 700 °C and 900 °C temperature. The sintered SnO2 nanoparticles, structural, optical, magnetic, morphological properties and microbial activity have been studied. XRD studies reveals that sintered powder which exhibits tetragonal crystal structure and both crystallinity as well as crystal size increase with increase in temperature. The morphological studies reveal randomly arranged grains with compact nature grain size increases with sintering temperature. The compositional analyses of SnO2 nanoparticles have been studied using X-ray photoelectron spectroscopy analysis. The optical band gap values of SnO2 nanoparticles were calculated to be about 4.3 eV in the temperature 500 °C, comparing with that of the bulk SnO2 3.78 eV, by optical absorption measurement. Room temperature M-H curve for pure SnO2 nanoparticles exhibits ferromagnetic behaviour. The tin oxide nanoparticles are acted as potential candidate material for bacterial and fungal activity.