Semi-Polycrystalline Polyaniline-Activated Carbon Composite for Supercapacitor Application.

We report on the synthesis of activated carbon-semi-polycrystalline polyaniline (SPani-AC) composite material using in-situ oxidative polymerization of aniline on the carbon surface in an aqueous HCl medium at an elevated temperature of 60 °C. The electroactive polymeric composite material exhibits a uniformly distributed spindle-shaped morphology in scanning electron microscopy (SEM) and well-defined crystallographic lattices in the high-resolution transmission electron microscopy (TEM) images. The X-ray diffraction (XRD) spectrum reveals sharp peaks characteristic of crystalline polyaniline. The characteristic chemical properties of polyaniline are recorded using laser Raman spectroscopy. The cyclic voltammetry curves exhibit features of surface-redox pseudocapacitance. The specific capacitance calculated for the material is 507 F g-1 at the scan rate of 10 mV s-1. The symmetrical two-electrodes device exhibits a specific capacitance of 45 F g-1 at a current density of 5 A g-1. The capacitive retention calculated was found to be 96% up to 4500 continuous charge-discharge cycles and observed to be gradually declining at the end of 10,000 cycles. On the other hand, Coulombic efficiency was observed to be retained up to 85% until 4500 continuous charge-discharge cycles which declines up to 72% at the end of 10,000 cycles. The article also presents a detailed description of material synthesis, the formation of polyaniline (Pani) chains, and the role of material architecture in the performance as surface redox supercapacitor electrode.

Good use of fruit wastes: eco-friendly synthesis of silver nanoparticles, characterization, BSA protein binding studies.

A simple and eco-friendly methodology for the green synthesis of silver nanoparticles (AgNPs) using a mango seed extract was evaluated. The AgNPs were characterized by ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The interaction between the green synthesized AgNPs and bovine serum albumin (BSA) in an aqueous solution at physiological pH was examined by fluorescence spectroscopy. The results confirmed that the AgNPs quenched the fluorophore of BSA by forming a ground state complex in aqueous solution. This fluorescence quenching data were also used to determine the binding sites and binding constants at different temperatures. The calculated thermodynamic parameters (ΔG°, ΔH° and ΔS°) suggest that the binding process occurs spontaneously through the involvement of electrostatic interactions. The synchronous fluorescence spectra showed a blue shift, indicating increasing hydrophobicity. Copyright © 2015 John Wiley & Sons, Ltd.

Interaction Studies of Greenly Synthesized Gold Nanoparticles with Bovine Serum Albumin (BSA) Using Fluorescence Spectroscopy.

In the present study, gold nanoparticles (AuNPs) with an average particle size of -41.23 nm were synthesized using eco-friendly reducing material (i.e., aqueous Nelumbo nucifera root extract). Rapid reduction results in the formation of polydispersed nanoparticles. The formation of AuNPs was characterized by surface plasmon resonance (SPR) which was determined by UV-Vis spectra (band at 544 nm), FTIR, SEM-EDX, TEM, HR-TEM, and XRD. This study aims to investigate the interaction between AuNPs and Bovine Serum Albumin (BSA) using fluorescence spectroscopy. The analysis of fluorescence spectra and intensity at physiological pH in an aqueous solution indicates that AuNPs have a potent ability to quench the BSA fluorescence by both quenching mechanisms. Resonance light scattering spectra indicated the formation of BSA-AuNPs complex. The number of binding sites and binding constants were determined based on fluorescence quenching at different temperatures. The thermodynamic parameters were also calculated at various temperatures that indicate that hydrophobic forces are abundant in the AuNPs-BSA complex. Negative ΔG degrees values suggest that the binding process is spontaneous. Synchronous fluorescence spectra showed a blue shift and CD spectra showed an increase in a-helicity content which is an indication of increasing hydrophobicity.

Characterization, antibacterial, antioxidant, and cytotoxic activities of ZnO nanoparticles using Coptidis Rhizoma.

Here, we report a simple, eco-friendly and inexpensive approach for the synthesis of zinc oxide nanoparticles (ZnO NPs) using Coptidis Rhizoma. The ZnO NPs were characterized by UV-visible absorption spectroscopy, FTIR, SEM-EDX, TGA, TEM, SAED and XRD. TEM images confirmed the presence of spherical and rod shaped ZnO NPs in the range of 2.90-25.20 nm. Green synthesized ZnO NPS exhibited moderate antibacterial activity against Gram-positive and Gram-negative bacteria and excellent DPPH free radical scavenging activity. Synthesized ZnO NPs had no toxic effects on the RAW 264.7 cell line.

Anti-melanoma, tyrosinase inhibitory and anti-microbial activities of gold nanoparticles synthesized from aqueous leaf extracts of Teraxacum officinale.

There has been a tenacious search for pharmaceuticals of natural origin, as they are cost-effective and are noted for having little or no side effects. The rate at which diseases are developing resistance to synthetic drugs is quite alarming, and the side effects of these drugs remain an excruciating agony to the pharmaceutical industry. Gold nanoparticles (AuNPs) have wide applications in current technology. However, their use in medicine has not been adequately explored. Chemical methods for the synthesis are associated with environmental benignity and tissue toxicity on in vivo administration. For the first time, we have synthesized AuNPs from leaf extracts of Teraxacum officinale that were found to have significant anti-melanoma, tyrosinase inhibitory and anti-microbial effects, and hence stand as promising candidates for use in cosmetics medical and food industries.

Novel approach to synthesize NiCo2S4 composite for high-performance supercapacitor application with different molar ratio of Ni and Co.

Here, we developed a new approach to synthesize NiCo2S4 thin films for supercapacitor application using the successive ionic layer adsorption and reaction (SILAR) method on Ni mesh with different molar ratios of Ni and Co precursors. The five different NiCo2S4 electrodes affect the electrochemical performance of the supercapacitor. The NiCo2S4 thin films demonstrate superior supercapacitance performance with a significantly higher specific capacitance of 1427 F g-1 at a scan rate of 20 mV s-1. These results indicate that ternary NiCo2S4 thin films are more effective electrodes compared to binary metal oxides and metal sulfides.

Determination of surface properties and Gutmann's Lewis acidity-basicity parameters of thiourea and melamine polymerized graphitic carbon nitride sheets by inverse gas chromatography.

Melamine and thiourea-derived graphitic carbon nitrides (M-GCN/T-GCN) were synthesized and characterized. The surface properties were investigated using inverse gas chromatography (IGC) and compared. Net retention volumes of M-GCN and T-GCN were measured with n-alkanes (C5-C10) and polar probes. The London dispersive surface free energies (γsd), calculated using Schultz and Dorris-Gray methods, decreased linearly with increasing temperature. The specific components of the enthalpy and entropy of adsorption for the polar probes were obtained using the Schultz, Dong, and Sawyer-Brookman methods. The Gutmann's Lewis acid-base parameters, Ka and Kb, were determined using the surface free energy (ΔGaS) via these methods. The surface character 'S' values (Kb/Ka) of M-GCN and T-GCN using the respective methods are 4.04, 3.78, and 5.08 and 4.11, 5.27, and 2.86. Hence, the surfaces contain more basic than acidic sites and could interact strongly with acidic media. Thus, IGC elucidates the surface charges of the GCN matrix resulting from surface chemical modification.

Ultra-sonication-assisted silver nanoparticles using Panax ginseng root extract and their anti-cancer and antiviral activities.

A simple, inexpensive ultra-sonication method was used to synthesize quasi spherical silver nanoparticles (AgNPs) with an aqueous extract from Panax ginseng roots. This method has the advantages of being completely eco-friendly and allows increased reaction rates, uniform dispersal of the nanoparticles in liquids, and effective breaking of aggregates. Biomolecules present in plant extracts are often used to reduce metal ions to nanoparticles in a single-step green synthesis route. The formation of the AgNPs was characterized using UV-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy- dispersive X-ray analysis (EDX), Fast Fourier Transform (FFT), and high-resolution transmission electron microscopy (HR-TEM). The formation of AgNPs (456 nm) was confirmed by UV-vis spectroscopy. HR-TEM analysis revealed that most of the AgNPs were quasi spherical with sizes ranging from approximately 5 to 15 nm. The crystalline nature of the AgNPs was confirmed by XRD, and the presence of elemental silver was confirmed by energy-dispersive X -ray analysis. The AgNPs showed dose-dependent cytotoxicity towards HeLa cells in vitro (3.88% at 0.005 M, 5.11% at 0.01 M, 7.52% at 0.015 M, 11.19% at 0.02 M, and 19.45% at 0.025 M) as revealed by sulforhodamine B assay. They were also shown to be virucidal against the influenza A virus (strain A/PR/8). Hence, the present facile, eco-friendly, and efficient method results in the synthesis of AgNPs that can act as an alternative biomaterial for future biomedical applications.

Degradation of organic pollutants by bio-inspired rectangular and hexagonal titanium dioxide nanostructures.

Dyes are used in textile, printing, leather, pharmaceutical, food and cosmetic industries. Dyes add color and pattern to materials. The presence of even very low concentration of dyes/dyes degradation products in effluent is highly toxic to humans and aquatic organisms. It is important to remove these dye degradation pollutants from the industrial effluents before their disposal. In recent years nanoparticles have been used for the removal of dyes from industrial waste water. Titanium dioxide nanostructures (TiO2 NS) were synthesized via a one-step facile green process. The formation of TiO2 NS was confirmed by Fourier transform infrared (FTIR) and Raman spectroscopy. Anatase (~76%) and rutile (~24%) phases were present, as determined by X-ray diffraction (XRD) analysis. X-ray photoelectron spectroscopy (XPS) was used to study the surface oxidation states of the TiO2 NS. High resolution transmission electron microscopy (HR-TEM) images revealed that the samples had hexagonal and rectangular morphologies, with diameters of ~24-32nm. The TiO2 NS were used to evaluate the photocatalytic activities of methylene blue (MB) and malachite green (MG) dyes under UV light and in dark conditions. After 60min of UV irradiation, nearly 71% of the MB and 78% of the MG was decolorized in the presence of as-synthesized TiO2 NPs.

In vitro anticancer potential of BaCO3 nanoparticles synthesized via green route.

Green synthesis of nanoparticles is a growing research area because of their potential applications in nanomedicine. Barium carbonate nanoparticles (BaCO3 NPs) were synthesized using an aqueous extract of Mangifera indica seed as a reducing agent. These particles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), selected area electron diffraction (SAED), Energy-dispersive-X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analysis. HR-TEM images are confirmed that green synthesized BaCO3 NPs have spherical, triangular and uneven shapes. EDX analysis confirmed the presence of Ba, C and O. The peaks at 2θ of 19.45, 23.90, 24.29, 27.72, 33.71, 34.08, 34.60, 41.98, 42.95, 44.18, 44.85, and 46.78 corresponding to (110), (111), (021), (002), (200), (112), (130), (221), (041), (202), (132) and (113) showed that BaCO3 NPs average size was ~18.3 nm. SAED pattern confirmed that BaCO3 NPs are crystalline nature. BaCO3 NPs significantly inhibited cervical carcinoma cells, as evidenced by cytotoxicity assay. Immunofluorescence and fluorescence assays showed that BaCO3 NPs increased the expression and activity of caspase-3, an autocatalytic enzyme that promotes apoptosis. According to the results, green synthesis route has great potential for easy, rapid, inexpensive, eco-friendly and efficient development of novel multifunctional nanoparticles for the treatment of cancer.

Toxicity and efficacy of CdO nanostructures on the MDCK and Caki-2 cells.

This article reports the toxicological effects of synthesized cadmium oxide (CdO) nanostructures via a simple green route using a Polygala tenuifolia root extract on normal and renal tumor cells. First, the formation of cadmium oxide nanostructures were confirmed structurally by Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). The powder was crystallized in a cubic structure with a space group of Fm-3m. The mean crystallize size was approximately 40 and 44nm from the Scherrer and size-strain plots, respectively. The surface states of the cadmium oxide nanostructure using the O 1s and Cd 3d spectra were analyzed by XPS. Transmission electron microscopy showed that the simple green route resulted in various morphologies of synthesized cadmium oxide, such as trigonal-, tetrahedron-, and sheet-like structures. Finally, the toxic effects of the cadmium oxide nanostructures on Madin-Darby canine kidney epithelial cells (MDCK cells), as well as the human renal cancer cell line (Caki-2 cells) were investigated using a SRB assay and two-color flow cytometry analysis. The cadmium oxide nanostructures showed significant cell growth inhibition in normal and also tumor cells in a dose-dependent manner. On the other hand, the inhibition was higher in the cancer cells compared to the normal cells.

Antioxidant and anti-inflammatory activities of zinc oxide nanoparticles synthesized using Polygala tenuifolia root extract.

The exploitation of various plant materials for the green synthesis of nanoparticles is considered an eco-friendly technology because it does not involve toxic chemicals. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using the root extract of Polygala tenuifolia. Synthesized ZnO NPs were characterized by UV-Vis spectroscopy, FTIR, TGA, TEM, SEM and EDX. Anti-inflammatory activity was investigated in LPS-stimulated RAW 264.7 macrophages, whereas antioxidant activity was examined using a DPPH free radical assay. ZnO NPs demonstrated moderate antioxidant activity by scavenging 45.47% DPPH at 1mg/mL and revealed excellent anti-inflammatory activity by dose-dependently suppressing both mRNA and protein expressions of iNOS, COX-2, IL-1ß, IL-6 and TNF-α.

Green synthesized silver nanoparticles using Nelumbonucifera root extract for efficient protein binding, antioxidant and cytotoxicity activities.

Silver nanoparticles (AgNPs) with a mean particle size of ∼ 16.7 nm were synthesized using an eco-friendly reducing material, aqueous Nelumbo nucifera root extract. Rapid reduction resulted in the formation of polydispersed nanoparticles. The formation of AgNPs was characterized by surface plasmon resonance, which was determined by ultraviolet-visible (UV-Vis) spectroscopy (band at 412 nm), Fourier transform infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy and X-ray diffraction. The interaction of the green synthesized AgNPs with Bovine Serum Albumin (BSA) at various temperatures was investigated. Fluorescence quenching, synchronous and resonance light scattering spectroscopy along with UV-Vis absorption studies revealed the efficient binding between BSA and the AgNPs. In addition, the AgNPs exhibited moderate antioxidant and cytotoxicity activities against HeLa cell lines.

Mycosynthesis: antibacterial, antioxidant and antiproliferative activities of silver nanoparticles synthesized from Inonotus obliquus (Chaga mushroom) extract.

In the present study, silver nanoparticles (AgNPs) were rapidly synthesized from silver nitrate solution at room temperature using Inonotus obliquus extract. The mycogenic synthesized AgNPs were characterized by UV-Visible absorption spectroscopy, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). SEM revealed mostly spherical nanoparticles ranging from 14.7 to 35.2nm in size. All AgNPs concentrations showed good ABT radical scavenging activity. Further, AgNPs showed effective antibacterial activity against both gram negative and gram positive bacteria and antiproliferative activity toward A549 human lung cancer (CCL-185) and MCF-7 human breast cancer (HTB-22) cell lines. The samples demonstrated considerably high antibacterial, and antiproliferative activities against bacterial strains and cell lines.