International Journal of Nanoscience

This paper analyzes the effects of additives on the properties of Iron oxide. The Iron oxide was synthesized using the co-precipitation method. The X-ray diffraction (XRD) peaks of resultant Iron oxide perfectly matched with JCPDS #860550 ($\alpha$ phase of Iron oxide / Hematite). The additives like Cobalt oxide, Nickel metal, Indium oxide and Tin metal with diverse properties procured in readymade forms were mechanically mixed with Iron oxide in 1:99, 3:97, 5:95 and 7:93 weight ratios, respectively. The XRD peaks for additives were prominent for 7:93 (Additive: Base Material) weight % ratio samples. Therefore, for further studies, only these samples were used. In this study, variations in XRD intensity, lattice parameters, unit cell volume, grain size, micro-strains (W-H analysis), dislocation density and stacking fault probability were analyzed. The specific surface area of particles was calculated by scanning electron microscope analysis. The presence of additives was also confirmed by energy dispersive spectra (EDS). The M-H loops (Vibrating Sample Magnetometer analysis) for samples under investigation showed rare vertical shifts. The weak magnetic behavior of bare Hematite (1.0 emu/gm) sample improved to antiferromagnetic behavior due to the addition of Cobalt oxide (7.89 emu/gm) and Nickel metal (2.76 emu/gm). The addition of Indium oxide (0.65 emu/gm) and Tin metal (0.73 emu/gm) samples showed a decreased magnetic saturation.

Metal nanostructures and noble metal-based nanostructures, in particular, exhibit plasmonic resonance in the visible region. The resonance absorption can be tuned by varying the size of nanoparticle and the external matrix in which the plasmonic materials are embedded. Mie’s theory has been used to demonstrate the shift in the plasmonic resonance in gold nanoparticles embedded in different dielectric media. Two model systems, viz. Au–ZnO and Au–Al₂O₃, prepared by sputtering on quartz substrates were used to study the optical absorption. The plasmonic peaks were observed to be red shifted in Au–Al₂O₃ and Au–ZnO, as is also supported by Mie formalism. The dielectric constant of the external matrix viz., Al₂O₃ and ZnO, estimated using the experimental and the Mie simulations are 3.05 and 1.83, respectively.

Silver nanoparticles (AgNPs) have attracted a great deal of attention in the recent years. It is mostly due to their availability, chemical stability, catalytic activity, conductivity, biocompatibility and anticancer activity. There are three major approaches for AgNPs synthesis; i.e., chemical, physical, and biological methods. Today, many chemical and physical methods have become less popular due to usage of hazardous chemicals or their high costs, respectively. The green method has introduced an appropriate substitute synthesis strategy for the conventional physical and chemical approaches. The utilization of the plant extracts as reducing, stabilizing and coating agent of AgNPs is an interesting eco-friendly approach leading to high efficiency. The anticancer synergistic effects among the AgNPs and phytochemicals will enhance their therapeutic potentials. Surprisingly, although many studies have demonstrated the significant enhancement in cytotoxic activities of plant-mediated AgNPs toward cancerous cells, these nanoparticles (NPs) have been found nontoxic to normal human cells in their therapeutic concentrations. This paper provides a specific insight into the mechanism of plant-mediated AgNPs synthesis, their anticancer and cytotoxic activities in vitro cancer cells, in vivo model animals and clinical trials.

The copper oxide, CuO, and copper hydroxide, Cu(OH)₂ nanomaterials have been prepared by a simple copper salt aqueous solution reaction. The powder X-ray diffraction (XRD) analysis showed the successful formation of Cu(OH)₂ and CuO nanoparticles. The average crystallite size of these Cu(OH)₂ and CuO nanoparticles was estimated and found to be around 17nm (Cu(OH)₂) and 10nm (CuO). The surface morphology and size of the CuO particles were confirmed by Scanning Electron Microscope (SEM) and High-resolution transmission electron microscope (HRTEM). The Raman analysis, dielectric and conductivity of CuO nanoparticles have been performed. The frequency variation of the capacitance (real dielectric constant) and dielectric loss was studied. The capacitance of the CuO nanoparticles is high at low frequencies and decreases rapidly when the frequency is increased. The frequency dependent ac conductivity follows Johnscher’s power law.

Silver nanoparticles were synthesized by chemical reduction of silver nitrate using arabinogalactan polysaccharide as a reducing agent and a stabilizer. The average size of nanoparticles, obtained by analyzing TEM-images, was 10.8nm; zeta potential $-20$mV. A study of the sol by electron diffraction showed that silver in the sample is in metallic form. The resulting preparation of silver nanoparticles showed both antibacterial and antifungal activity. A pronounced antibacterial activity of silver nanoparticles was demonstrated both in relation to conditionally pathogenic gram-positive (Bacillus subtilis and B. coagulans) and gram-negative (Escherichia coli) bacteria. Silver nanoparticles also possess antifungal activity against macromycete Fomitopsis sp., as well as two strains of micromycetes Trichoderma citrinoviride and Fusarium sporotrichioides. Using the methods of light and fluorescence microscopy, MTT-analysis and Real-time cell analysis, the cytotoxic activity of silver nanoparticles was investigated on HepG2 human hepatocellular carcinoma cells. It was demonstrated that nanoparticles cause a suppression of cell metabolic and proliferative activity, as well as dose-dependent induction of cell death (average relative EC${}_{50}$ value was $9\pm 2.7\mu$g/ml). The preparation of silver nanoparticles stabilized by arabinogalactan can be used in medicine, as a potential antimicrobial and antitumor agent.

The toxic impacts of zinc oxide nanoparticles (ZnO NPs) on reproductive potential of the earthworm, Eisenia fetida were studied in relation to varying temperature and pH in natural (NS) and artificial substrate (AS). The ZnO NPs decreased cocoon production, hatching and rate of reproduction as a function of increasing concentration, temperature and exposure period. The gradation of temperature and pH to get a better reproductive potential was found to be $25^{\circ }\mathrm{\text{C}}>20^{\circ }\mathrm{\text{C}}>30^{\circ }$C and $6.5>7.5>5.5$, respectively. Cocoon production was higher in NS than the AS. It may be due to sufficient food availability in NS. Survival of adult worms was decreased with increase in ZnO NPs and exposure period. The rate of reproduction was significantly higher in NS as compared to AS at $25^{\circ }$C. The present findings suggested that ZnO NPs retard the reproductive potential of E. fetida and may also be hazardous to pedoecosystem and fauna living there in. Temperature of $25^{\circ }$C, pH 6.5 and NS as vermibed were the most suitable conditions to maintain worthy rate of reproduction and reduce ZnO NPs toxicity.

One-step preparation method of metal-carbon nanocomposites based on bimetallic Co–Ru nanoparticles supported and IR carbonized polyacrylonitrile was proposed. IR pyrolysis of the precursor based on joint solution of polyacrylonitrile and metal compounds leads to the simultaneous formation of carbon support and bimetallic metal nanoparticles. The metal reduction occures due to the release of hydrogen during decomposition of backbone polymer chain. Furthermore, IR radiation shortens fabrication time significantly. It was shown that the presence of cobalt and ruthenium in the system provides the creation of alloy Co–Ru nanoparticles. In addition, cobalt provides a formation of structured carbon shells around bimetallic nanoparticles. The nanocomposites were tested as catalysts for the hydrogen production through ethanol steam reforming. The dependence of structural and functional properties on the metal loading was demonstrated. The high yield of hydrogen was recorded for all three samples, whereas the by-product yield was relatively low.

The Cs${}_{0.3}$WO₃/WO₃ composite with near-infrared shielding properties was synthesized by the solvothermal method using tungstic acid and cesium salt as raw materials. The as-prepared composites were tested by X-ray powder diffraction, scanning electron microscopy, energy spectrum analysis, transmission electron microscopy, electron energy loss spectroscopy, and ultraviolet-visible near-infrared spectroscopy. The effects of different reaction conditions on the structure and near-infrared shielding properties of the synthesized composites were investigated. The best near-infrared light transmittance of as-prepared composites can reach up to 9%, which provides a feasible solution for the near-infrared shielding material. The new homogeneous composites of cesium tungsten bronze and tungsten oxide are good candidates for solar filters.

The convenient nanotransdermal delivery system is always likely to have some ideal and unique characteristics, predominantly for safety, desired actions, clinical efficacy, enriched with a therapeutic index with minimal adverse occurrence. One of the most challenging tasks for the formulators is to transfer the medicament, especially macromolecules, through the skin. Some of the ways to achieve this is the use of a painful needle or some other methods which also have economical constraints. A new technology has been developed, that is ultradeformable liposomes, also called as transfersomes. These are an elastic type of lipid vesicle aggregates capable of delivering wide range of active moieties including various biomolecules. It can be manufactured by evaporation, vortexing, reverse-phase evaporation, ethanol injection or freeze-thaw methods, where phospholipids and edge activators are the major ingredients that contribute the main role in their unique mechanism of permeation through less permeable stratum corneum. This review mainly focuses on the clinical trial studies and patents accessible on transfersomal products worldwide, highlights the recent work on transfersomes with various therapeutic agents. An effort to explain the deeper penetration of transfersomes across the epidermis layer by its pharmacokinetics and dynamic properties has been taken.

In this study, ZnO–Fe₂O₃ nanocomposites were prepared by high-energy ball milling technique and characterized through X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), UV–visible spectroscopy and dielectric spectroscopy. The amount of Fe₂O₃ in the ZnO–Fe₂O₃ nanocomposites was varied at the rates of 1wt.%, 3wt.% and 5wt.% in order to investigate its influence on the structural, optical and dielectric properties of the nanocomposites. XRD patterns of nanocomposites revealed no shift in peak positions and hence confirmed the formation of composites after ball milling. Further, it was observed from FESEM analysis that Fe₂O₃ particles were distributed randomly on the ZnO matrix of the nanocomposites. ZnO–Fe₂O₃ nanocomposites reveal extended optical absorption in the range of 400–600nm from UV studies. The dielectric constant and loss of the nanocomposites decrease exponentially with increase in frequency. The composition and frequency dependences of the dielectric constant, dielectric loss and AC conductivity are explained based on the Maxwell–Wagner effect and Koop’s theory.