Polymer-encapsulated gold or silver nanoparticles were synthesized and sterically stabilized by a shell layer of poly(4-vinylpyridine) (P4VP) grafted on SiO(2) nanoparticles that acts as a scaffold for the synthesis of hybrid noble metal nanomaterials. The grafting P4VP shell was synthesized via surface reversible addition-fragmentation chain transfer (RAFT) polymerization of 4-vinylpyridine (4VP) using SiO(2)-supported benzyl 9H-carbazole-9-carbodithioate (SiO(2)-BCBD) as the RAFT agent. The covalently tethered P4VP shell can coordinate with various transition metal ions such as Au(3+) or Ag(+) and therefore stabilize the corresponding Au or Ag nanoparticles reduced in situ by sodium borohydride (NaBH(4)) or trisodium citrate. The SiO(2)-supported RAFT agent and the Au or Ag nanoparticles embedded in the P4VP shell layer were characterized by UV-vis spectrophotometer, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and surface-enhanced Raman spectroscopy (SERS).

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Over the last two decades, remarkable progress has been made in use of computational methods for understanding 2D materials growth. The aim of this Review is to provide an overview of several state-of-the-art computational methods for the modelling and simulation of 2D materials growth. First, the current status of 2D materials, and their major growth methods are addressed. Next, the applications of the ab initio method in 2D materials growth is discussed, focusing on reaction of precursors, diffusion of adatoms, energetics and kinetics of growth fronts, and effects of substrates. Then, the applications of the molecular dynamics approach in 2D materials growth is discussed, with emphasis on the growth of graphene on various substrates and the growth of boron nitride and silicene. Furthermore, the applications of the kinetic Monte Carlo method in 2D materials growth are discussed. The parametrization of the method and its application in dimer distribution, and nonlinear edge growth of graphene are discussed. Subsequently, the applications of the phase-field method in 2D materials growth are discussed, focusing on the growth rate and morphological evolution of 2D domains. Finally, perspectives and conclusions are presented.

A novel and highly sensitive immunoassay method based on surface enhanced Raman spectroscopy (SERS) and magnetic particles has been developed. This method exhibits great potential application in bio-separation and immunoassay.

It is well documented that orientation discrimination is poorer for stimuli oriented obliquely than for those that are vertical or horizontal. Buchanan-Smith and Heeley recently reported that in the absence of a spatial reference this anisotropy follows gravitational rather than retinal coordinates, suggesting a high-level basis for the anisotropy in unreferenced orientation discrimination tasks. In the present study, unlike the previous one, the effects of body tilt on orientation discrimination have been examined in the presence of explicit simultaneous spatial references. The thresholds for discrimination of two parallel or two perpendicular lines were estimated for the retinally principal and oblique orientations, with the body either erect or tilted 45 degrees with respect to gravity. In agreement with previous studies, meridional anisotropy for both parallelism and perpendicularity discrimination was found when observers were seated upright. When the observer's body was tilted, the anisotropy for the parallelism task was mapped to retinal and not to gravitational coordinates after compensating for countertorsion. Initially, the anisotropy for the perpendicularity task was not mapped to retinal coordinates, but after extensive practice for both the erect and the tilted body conditions it eventually followed retinal coordinates. The results reported here suggest that contrary to orientation discrimination without a spatial reference, the ultimate limits for both parallelism and perpendicularity discriminations are located at orientation-sensitive cortical neurons. However, the effect of perceptual learning in the perpendicularity task suggests that the internal frame of reference (gravity cues and body axis) also plays an important role.

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A femtogram level and specific surface enhanced Raman spectroscopy (SERS) based competitive immunoassay was developed to detect Hg(II) in aqueous solution for the first time. This novel approach provides an alternative, ultrasensitive and specific analytical method for the detection of Hg(II).