Continuous and uniform graphene films were directly grown on SiO 2 substrates using a chemical vapor deposition system with two-temperature zones assembled. The carbon species from the high temperature zone nucleate in the low temperature zone, initiating the growing process of graphene. The films are

A novel and efficient surface enhanced Raman scattering (SERS) substrate has been presented based on Gold@silver/pyramidal silicon 3D substrate (Au@Ag/3D-Si). By combining the SERS activity of Ag, the chemical stability of Au and the large field enhancement of 3D-Si, the Au@Ag/3D-Si substrate possesses perfect sensitivity, homogeneity, reproducibility and chemical stability. Using R6G as probe molecule, the SERS results imply that the Au@Ag/3D-Si substrate is superior to the 3D-Si, Ag/3D-Si and Au/3D-Si substrate. We also confirmed these excellent behaviors in theory via a commercial COMSOL software. The corresponding experimental and theoretical results indicate that our proposed Au@Ag/3D-Si substrate is expected to develop new opportunities for label-free SERS detections in biological sensors, biomedical diagnostics and food safety.

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In this work, the dynamic change of the absorbance for aqueous ethanol detection based on a graphene oxide coated U-bent optical fiber sensor was investigated.

We present a novel surface-enhanced Raman scattering (SERS) substrate based on graphene oxide/silver nanoparticles/copper film covered silicon pyramid arrays (GO/AgNPs/PCu@Si) by a low-cost and simple method. The GO/AgNPs/PCu@Si substrate presents high sensitivity, good homogeneity and well stability with R6G molecules as a probe. The detected concentration of Rhodamine 6 G (R6G) is as low as 10−15 M. These sensitive SERS behaviors are also confirmed in theory via a commercial COMSOL software, the electric field enhancement is not only formed between the AgNPs, but also formed between the AgNPs and Cu film. And the GO/AgNPs/PCu@Si substrates also present good property on practical application for the detection of methylene blue (MB) and crystal violet (CV). This work may offer a novel and practical method to facilitate the SERS applications in areas of medicine, food safety and biotechnology.

A series of Co-doped ZnO thin films were prepared under various deposition conditions using the pulsed laser deposition method. X-ray photoelectron spectroscopy (XPS) and XPS depth profiling were used to detect the elemental valence states of Zn, Co and O. It was found that the films deposited under low temperature and high oxygen pressure exhibited intrinsic ferromagnetic properties due to oxidation of Co (Co2+) from the material. However, when the films were deposited under high temperature and low oxygen pressure, metallic cobalt (Co0) appeared and the ferromagnetism was greatly enhanced

c-axis preferential orientated ZnO:Co thin films were synthesized onc-plane sapphire substrates by using pulsed laser deposition (PLD) technique in an oxygen-deficient ambient. X-ray diffraction spectra, scanning electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, UV-vis transmittance spectra, and Raman spectra were used for characterization. Ferromagnetic behavior was clearly observed at room temperature and verified to be the intrinsic property of the material. The presence of second phase was ruled out.

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