In this work, we experimentally investigated the surface-enhanced Raman spectroscopy (SERS) activity of faceted gold nanoparticles, which have been theoretically predicted to yield giant enhancements. Glycine was used to determine the SERS activity as a function of pH and ionic strength and to estimate the corresponding enhancement factor (EF). By optimizing the synthesis conditions of the flat prismatic nanoparticles, it was possible to control their size and shape. We demonstrate that the maximum SERS intensity increases with the edge length of the triangle, reaching a maximum EF of ∼10 13 for 1.9 µm triangles (the largest tested). The corresponding glycine detection limit was as low as 10 −12 M, close to the single-molecule threshold.

Controlled amounts of nanoparticles ranging in size and composition were embedded in the walls of carbon nanotubes during a template-assisted chemical vapour deposition (CVD) process. The encapsulation of gold nanoparticles enabled surface enhanced Raman spectroscopy (SERS) detection of glycine inside the cavity of the nanotubes. Iron oxide particles are partially reduced to metallic iron during the CVD process giving the nanotubes ferromagnetic behaviour. At high nanoparticle concentrations, particle agglomerates can form. These agglomerates or larger particles, which are only partially embedded in the walls of the nanotubes, are covered by additional carbon layers inside the hollow cavity of the tube producing hillocks inside the nanotubes, with sizes comparable to the bore of the tube.

Two competing effects at two vastly different scales may explain collagen's current translation length. The necessity to have long molecules for maintaining mechanical integrity at the organism and supraorganism scales may be limited by the need to have small molecules capable of robust self-assembly at the nanoscale. The triglycine repeat regions of all 556 currently cataloged organisms with collagen-like genes were ranked by length. This revealed a sharp boundary in the GXY transcript number at 1032 amino acids (344 GXY repeats). An anomalous exception, however, is the intron-free Trichodesmium erythraeum collagen gene. Immunogold atomic force microscopy reveals, for the first time, the presence of a collagen-like protein in T. erythraeum. A phylogenetic protein sequence analysis which includes vertebrates, nonvertebrates, shrimp white spot syndrome virus, Streptococcus equi, and Bacillus cereus predicts that the collagen-like sequence may have emerged shortly after the divergence of fibrillar and nonfibrillar collagens. The presence of this anomalously long collagen gene within a prokaryote may represent an interdomain transfer from eukaryotes into prokaryotes that gives T. erythraeum the ability to form blooms that cover hundreds of square kilometers of ocean. We propose that the collagen gene entered the prokaryote intron-free only after it had been molded by years of mechanical selective pressure in larger organisms and only after large, dense food sources such as marine vertebrates became available. This anomalously long collagen-like sequence may explain T. erythraeum's ability to aggregate and thus concentrate its toxin for foodsource procurement.

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Electrodeposition of tertiary Alumina/Yitria/carbon nanotube (Al 2 O 3 /Y 2 O 3 /CNT) nanocomposite by using pulsed current has been studied. Coating process has been performed in nickel sulphate bath and nanostructure of the obtained compound layer was examined with high precision figure analysis of SEM nanographs. The effects of process variables, i.e. Y 2 O 3 concentration, treatment time, current density and temperature of electrolyte have been experimentally studied. Statistical methods were used to achieve the minimum wear rate and average size of nanoparticles. Finally the contribution percentage of different effective factors was revealed and confirmation run showed the validity of the obtained results. Also it has been revealed that by changing the size of nanoparticles, wear properties of coatings will change significantly. Atomic force microscopy (AFM) and transmission electron microscope (TEM) analysis have confirmed smooth surface and average size of nanoparticles in the optimal coating. Key words: yitria, electrodeposition, tertiary nanocomposite coatings, wear, carbon nanotube.Nickel and nickel-based alloys are used widely for numerous applications, which most of them require corrosion, wear and heat resistances, including different turbine plants, nuclear power systems, and chemical and oil industries.Ceramic or metal matrix nanocomposite coatings usually have special properties such as dispersion hardening, self-lubricity, high temperature inertness, good wear and corrosion resistance, chemical and biological compatibility [1][2][3][4][5][6][7]. This accounts for the increased application of Ni-based nanocomposites in different industries. In order to meet the requirement for developing novel metal-based nanocomposites, many preparation techniques have been investigated. Considering a technique conducted at a normal pressure and ambient temperature and with low cost and high deposition rate, electrodeposition is considered to be one of the most important techniques for producing nanocomposites and nanocrystals [8][9][10][11].In this paper, tertiary nanocomposite coatings consisting of nanometric-sized Al 2 O 3 /Y 2 O 3 /CNT particles embedded in a Ni-matrix by pulsed electrodeposition method were studied. The nanostructure and wear resistance of obtained nanocomposites were investigated with respect to the different effective factors of coating process. Ni matrix composite coatings containing nano-sized Al 2 O 3 /Y 2 O 3 /CNT fine particles with different average sizes of nanoparticles were prepared in a nickel sulphate bath. The wear performance of these coatings and its relation to the distribution of nanopaticles has been analyzed in a systematical way.The design of experiment (Taguchi method) [12][13] took into account the influencing extent of individual process parameter. This consideration led to the selection of four influential factors, i.e. Y 2 O 3 concentration, time, current density and