Noble-metal nanoparticles embedded in dielectric matrices are considered to have practical applications in ultrafast all-optical switching devices owing to their enhanced third-order nonlinear susceptibility, especially near the surface-plasmon-resonance (SPR) frequency. Here we present the use of a microreactor approach to the fabrication of a self-organized photosensitive gold nanoparticle chain encapsulated in a dielectric nanowire. Such a hybrid nanowire shows pronounced SPR absorption. More remarkably, a strong wavelength-dependent and reversible photoresponse has been demonstrated in a two-terminal device using an ensemble of gold nanopeapodded silica nanowires under light illumination, whereas no photoresponse was observed for the plain silica nanowires. These results show the potential of using gold nanopeapodded silica nanowires as wavelength-controlled optical nanoswitches. The microreactor approach can be applied to the preparation of a range of hybrid metal-dielectric one-dimensional nanostructures that can be used as functional building blocks for nanoscale waveguiding devices, sensors and optoelectronics.

The sound level measured in the enclosed space was quieter than in the open space. The design of bed space should be taken into consideration when building a new NICU. Besides the design of NICU architecture, continuous monitoring of sound level in the NICU is important to maintain a quiet environment.

Silicon nanowires (SiNWs) have been used as the sensing layer in an extended gate field effect transistor (EGFET) for the measurement of pH solutions. The SiNWs were synthesized directly from the silicon substrates via a catalytic reaction under N 2 atmosphere at 955 o C without supplying any gaseous or liquid Si sources. Nickel catalyst was deposited on the silicon substrates by sputtering. The average diameter of the SiNWs was about 30 ~ 50 nm and a length of up to a few tens of micrometers. In this research, the silicon bulk materials and SiNWs were used respectively as the sensing layer in an extended gate field effect transistor to measure the sensitivity of the pH solutions. Experimental results showed that the pH sensitivity of silicon bulk materials is poor. However, a good pH sensing properties of SiNWs, with sensitivities in the range of 58.3mV/pH, was observed. Therefore, it was suggested that the pH sensitivity of silicon bulk materials was greatly improved by downsizing into nanoscale.

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