Advanced Materials Research Vol. 1086

Abstract: Green chemical approach is adopted for the synthesis of silver nanoparticles (Ag NPs). Since the nanoparticles tend to aggregate during the course of the catalytic reaction, they need to be stabilized by employing a suitable template or a support. Hence the prepared nanoparticles were loaded on titania support and used as a photocatalyst. Silver loaded titania (Ag-TiO₂) is characterized by UV-visible spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic absorption spectroscopy (AAS). Prepared composite was also tested for its photocatalytic activity against the degradation of an industrial pollutant Rhodamine B dye. Effect of pH, ratio between the catalyst and the substrate and also the role of free radical generator in the degradation have been tested and summarized in this work.Keywords: Silver nanoparticles, Phytochemical preparation, Green chemical approach, Photocatalysis, Rhodamine B

Abstract: Green synthesis of silver nanoparticles using banana sap as a solvent, reducing agent and capping agent is reported in this work. Banana sap has also been used as a binder to incorporate silver nanoparticles into cotton fabric. UV-Visible spectroscopy was used to monitor the quantitative formation of silver nanoparticles. Silver nanoparticle coated fabric showed high antimicrobial activity against gram negative bacteria such as Pseudomonas aureginosa and Escherichia coli, and gram positive bacteria such as Bacillus subtilis and Staphylococcus aureus.KeywordsGreen synthesis, Silver nanoparticles, banana sap, antimicrobial activity

Abstract: Metallic nanoparticles have received great attention from chemists, physicists, biologists and engineers who wish to use them for the development of a new generation of nanodevices. In the present Communication, a completely “green” chemistry method for producing silver nanoparticles is introduced. The process is simple, environmentally benign, and quite efficient. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and ecofriendly reducing and capping agents. In particular, silver nanoparticles are proved to have potential antibacterial, antifungal and antiplasmodial and antimicrobial properties. The present study was aimed to identify the antiplasmodial activity of green synthesised silver nanoparticles (AgNPs) using aqueous extract of plant Euphorbia hirta against P.falciparum. Nanoparticles are being used in many commercial applications. It was found that aqueous silver ions can be reduced by aqueous extract of plant to generate extremely stable silver nanoparticles in water. The bio-reduced silver nanoparticles were appropriately characterized by UV–vis spectrum, Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The formation of the AgNPs synthesized from the XRD spectrum compared with the standard confirmed spectrum of silver particles formed in the present experiments were in the form of nanocrystals, as evidenced by the peaks at 2θ values of =28.01°, 32.41°, 46.44°, 55.05° and 57.75°. The scanning electron micrograph (SEM) showed structures of spherical, cubic shape, and the size range was found to be 30–60 nm. The EDX spectra showed the purity of the material and the complete chemical composition of the synthesized AgNPs. The parasitic inhibition was dose-dependent. The synthesized AgNPs showed considerable antiplasmodial activity than the crude methanol and aqueous leaf extract of E.hirta. The maximum efficacy was

Abstract: The prospective of the use of the silver nanoparticle complexes of glycyrrhizic acid in combating drug induced oxidative stress was studied by using three different model systems; paracetamol induced acute hepatotoxicity, doxorubicin induced acute cardiotoxicity and cisplatin induced acute renal toxicity in Swiss albino mice. The animals were administered with silver nanoparticle complexes of glycyrrhizic acid prior to the induction of paracetamol/doxorubicin/cisplatin toxicity and various parameters such as serum marker enzymes, tissue antioxidants and hisopathological analyses were performed. The results on the serum marker enzymes, tissue antioxidants and hisopathological analyses established the ability the complexes to offer protection to various organ systems against the oxidative damage induced by the respective drug treatments.Keywords Silver Nanoparticle, histopathology, paracetamol, doxorubicin, cisplatin

Abstract: The present study aims to target a cytotoxic drug, Berberine to tumor tissues specifically by the use of iron oxide nanoparticles and a nitro triazole compound, Sanazole which gets accumulated in hypoxic tumor tissue. Under in vitro conditions the nanoparticles complexed with Berberine and Sanazole showed higher cytotoxicity to tumor cells than either of the drugs and complexes of single individual compounds. The tumor-bearing animals treated with these nanoparticle-drug complexes increased the regression in tumor volume and survival of the animals. The present work thus revealed the potential applications of Berberine and Sanazole in cancer therapy.

Abstract: Hydroxyapatite (HAP) Ca₁₀(PO)₆(OH)₂ is widely used as a bioactive ceramics since it forms a chemical bonding to bone. The dominant requirement for the development of HAP coatings on metallic implants is the preparation of stoichiometric material with required chemical and phase composition (Ca/P molar ratio 1.67). In this work the preparation of HAP films by sol-gel method on alumina and its characterization are described. The coating was done using dip-coating method, starting from a colloidal suspension of hydroxyapatite. Compound formation of HAP is confirmed using GIXRD. By Energy Dispersive X-Ray spectroscopy (EDX) analysis Ca/P ratio of the HAP was found to be 1.657 which is very close to the stoichiometric value of 1.67. The FTIR spectra of the coatings were used to determine the presence of chemical species of the coatings. Surface Characterization has been carried out using SEM & AFM techniques. Wettability study has been carried out using OCA and it was found that hydrophobicity decreases with the increase in HAP thickness. Corrosion studies have been carried out using electrochemical analyzer (ECA) in Ringer solution and best corrosion resistance was observed for the thickest sample. The paper discusses the variations in surface morphology using SEM, AFM & EDX and its effect on biocompatibility.

Abstract: Nanorobotics is the technology of creating robots at nanoscale. Specifically, nanorobotics refers to the hypothetical nanotechnology engineering discipline of designing and building nanorobots, devices ranging in size from 0.1-10 micrometers and constructed of molecular components. On this concept of artificial non-biological nanorobots, many research centers are performing the research activities. The names nanobots, nanoids, nanites or nanomites have also been used to describe these hypothetical devices. They are applied in advanced medical applications like diagnosis and treatment of diabetes, early detection and treatment of cancer, cellular nonosurgery and genetherapy. A few generations from now someone diagnosed with cancer might be offered a new alternative to chemotherapy. A doctor practicing nanomedicine of chemotherapy would offer the patient an injection of a special type of nanorobot that would seek out cancer cells and destroy them, dispelling the disease at the source, leaving healthy cells untouched unlike the traditional treatment of radiation that kills not only cancer cells but also healthy human cells. Radiation treatment may also cause hair loss, fatigue, nausea, depression, and a host of other symptoms. Thus in nanorobotics, the extent of the hardship to the patient would essentially be a prick to the arm. A person undergoing a nanorobotic treatment could expect to have no awareness of the molecular devices working inside them, other than rapid betterment of their health. A major advantage that nanorobots provide is durability, as they could last for years. The operation time would also be much lower because their displacements are smaller. Hence reduced material costs, accessibility to previously unreachable areas are the motivating factors. Thus our review explains that the designing and testing of primitive devices and their potential applications promise rich benefits for patients, medical personal, engineers, and scientists.

Abstract: In this study, we investigated the photovoltaic efficiency of DSSC (Dye Sensitized Solar Cell) using five different organic dyes extracted from natural sources namely Gomphrena globosa, Syzygium cumini (fruit and leaf), Crocus sativus, Caesalpinia sappan and Rubia cordifolia. Commercially obtained TiO₂ powder, coated over the conducting glass substrate was used as the photo anode and the same coated with carbon soot was used as the photo cathode. UV spectrophotometer and photoluminescence spectrophotometer were used to characterize the dyes to find their absorption and emission maxima respectively. X-Ray diffractometer was used to characterize the TiO₂ electrode film. SEM analysis was also carried out to study the surface morphology. The life and efficiency of DSSC can be improved by studying the dye absorption process and the thickness, size and shape of TiO₂ coating. Thus, low cost solar cells can be developed with significant power conversion efficiency.Key words: TiO_2, DSSC, natural dyes, ITO glass slides, carbon soot, sintering.

Abstract: Monodispersed polyvinylpyrrolidone capped nanostructures of zinc oxide are prepared through chemical precipitation technique. The prepared nanostructures are characterized by XRD, SEM and Photoluminescence spectroscopic techniques. X-ray diffraction studies confirm the hexagonal structure of zinc oxide nanostructures. Nanostructures of the prepared zinc oxide are confirmed by SEM. The emission wavelength of PVP capped zinc oxide is found to be 551 nm using photoluminescence spectra.