We present a study of the relation between the surface chemistry and nanocrystal shape of PbSe nanocrystals with a variable Pb-to-Se stoichiometry and density of oleate ligands. The oleate ligand density and binding configuration are monitored by nuclear magnetic resonance and Fourier transform infrared absorbance spectroscopy, allowing us to quantify the number of surface-attached ligands per ...

We investigate the evolution of copper phthalocyanine thin films as they are etched with argon plasma. Significant morphological changes occur as a result of the ion bombardment; a planar surface quickly becomes an array of nanopillars which are less than 20 nm in diameter. The changes in morphology are independent of plasma power, which controls the etch rate only. Analysis by X-ray photoelect...

A sensitive surface enhanced Raman scattering chemical sensor is demonstrated by using inexpensive gold-coated nanoporous anodic aluminum oxide substrates. To optimize the performance of the substrates for sensing by the Surface-enhanced Raman scattering (SERS) technique, the size of the nanopores is varied from 18 nm to 150 nm and the gold film thickness is varied from 30 nm to 120 nm. The sen...

Metal nanoparticles were utilized as heating elements within nanofibers to demonstrate an alternative approach to thermally process nanostructured polymeric materials. In the photothermal process, resonant light excites the surface plasmon of the nanoparticle and the absorbed energy is converted into heat due to electron-phonon collisions. This heating is efficient and strongly localized, gener...

Bacterial ferritin from Azotobacter vinelandii (AvBFJ has a function in H2 uptake. The Fe3+ reduction on the surface of the iron core from AvBF0 is accompanied simultaneously by H2 uptake, with a maximum activity of H2 uptake of 450 H2/AvBF0. A reduction potential of -402 mV for iron reduction on the surface of the core is found. A shift to the red the protein absorbance peaks ranging from 280 ...

Primitive photosynthetic microorganisms, either dormant or dead, may remain today on the martian surface, akin to terrestrial cyanobacteria surviving endolithically in martian analog sites on Earth such as the Antarctic Dry Valleys and the Atacama Desert. Potential markers of martian photoautotrophs include the red edge of chlorophyll reflectance spectra or fluorescence emission from systems of...

Pure and doped magnesium oxide (MgO) thin films were prepared with different volumetric ratios (0, 2, 4, 6, 8%) of zinc sulfide (ZnS) on glass substrates at (350 °C) by chemical spray pyrolysis technique. The surface topography, absorption spectrum, coefficient Urbach energy the studied. atomic force microscopy (AFM) results revealed that topography changes as percentage doping increases. absor...

Specific absorbance (A|) is the maximum absorbance of a 1% solution over a 1-cm path length as measured by a spectrophotometer. If a reliable A| determination is available for a drug, it provides an extremely useful tool for the quantitative verification of a stock drug solution. Zaleplon was introduced into the market in 1999, and although the drug has been available for 10 years, A| has not b...

Extraction of DNA is very important nowadays in bio-molecular researches. Extracted DNA should be purified and the quality of DNA should also be very high. The objective of the study was to develop a simple efficient method to isolate DNA from the rice varieties in an open laboratory environment, and to eliminate the usage of expensive chemicals and tools. The DNA extraction methods developed b...

in this paper we report an eco-friendly route for the synthesis of sliver nanoparticles using agaricus bisporus (white button mushroom) extract. the synthesized silver nanoparticles were confirmed and characterized by uv-visible spectrum of the aqueous solution containing silver ions showed a peak at 420 nm corresponding to the surface plasmon absorbance of silver nanoparticles. transmission el...