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Cell viability is a crucial issue in biological research. We present label-free monitoring of adhesion cells viability by gold nanoslits-based Fano resonance biosensors. Plastic multiple wells with gold nanoslits substrate were made using a thermal nanoimprint method. Adhesion cells in the wells were treated with doxorubicin for inducing cell death and compared with conventional colorimetric assay. The nanoslits method shows better respones of viability tests under low concentration and short interaction time due to its high surface sensitivies. The vinculin labelling indicates that the measured signals are in good agreement with the adhesion abilities of cells.

A large-area and periodically patterned nanoporous aluminum grid with controlled pore size was fabricated by poly(ethylene oxide)-assisted self-assembly of polystyrene nanospheres. The grid layer was used as the shadow mask for the creation of nanochannels in a polymeric dielectric layer, as well as the base electrode in a space-charge limited transistor prepared thereafter. A high performance device with poly(3-hexylthiophene) as conducting semiconductor was achieved, yielding a high on-current output of ∼12 mA/cm2 and a high on-off ratio of ∼2 × 104 at a collector voltage of −2.0 V.

We study the optimal sensing condition for periodic gold nanoslits. The intensity sensitivities for various periods, from 400 to 900 nm, were measured. The experimental results show that 500-nm-period array has a maximum bulk sensitivity, three times larger than the sensitivities of 400 and 700 nm periods. The optimal period is attributed to the coincidence of the surface plasmon resonance (SPR) wavelength and lowest imaginary dielectric constant of gold film. The structure reaches a figure of merit of 23.9 and achieves a detection limit of 2.6 × 10−5 refractive index units at 0.2% stability, better than the grating-based SPR sensors using intensity interrogation.

By using femtosecond laser-ultrasonic, we demonstrate an approach to study the surface plasmon field optically excited in the interface between metal and a semiconductor thin film. By femtosecond impulsive excitation on gallium–nitride (GaN), different optical probe signals were observed when the impulse-excited nanoacoustic pulse propagated through the metal film and metal nanoslits. By analyzing the shape and temporal response of thus induced acousto-optical signals, our femtosecond laser-ultrasonic study not only reveals the plasmonic field distribution optically excited in the metal/substrate interface but also confirms that the penetration depth of surface plasmon field into the substrate agrees well with a simulation result.

We have developed an approach to prepare large array nanostructured thin films using polyethylene oxide assisted self-assembly of polystyrene nanospheres as a template. By tuning the antidot diameter in the cobalt thin films, we found a crossover behavior in the magnetization reversal process. In addition, the effective moment per cobalt atom turns out to drop with growing antidot diameter which effectively increases the surface to bulk volume fraction. Our results suggest a tendency of reduced saturation magnetization in a ferromagnet/normal metal interface, where the mixing of itinerant electrons with ferromagnetic d electrons can give rise to observable effect.

Large phase differences between transverse electric (TE) and transverse magnetic (TM) waves were investigated in plasmonic nanoslit arrays. The phase of the TE wave shifts ahead because of its low propagation constant. On the other hand, the phase of the TM wave is retarded due to the propagation of surface plasmons. The opposite phase shift forms a giant birefringence. Its magnitude was dependent on the width of nanoslits. The birefringence magnitude was ∼1 for 300-nm-wide nanoslits and up to ∼2.7 for 100 nm ones. The spectroscopic measurements indicate that waveplates made of gold nanoslits have large bandwidths.

The extraction efficiency of organic light emitting devices is enhanced by depositing metallic nanowires on the glass surface and indium tin oxide (ITO) anode. For the aluminum tris-(8-hydroxyquinoline) (Alq3) based devices, a 100nm-width and 450nm-period gold nanowire array increases light extraction up to 46% from glass substrate and 80% from the organic layer. Such metallic nanowire arrays double the brightness with small absorption, only 10% lower than ITO glass. In addition, colors of the devices can be selected by the period of nanowire array. We demonstrated blue to red light emission by using single Alq3-based device.

The detection sensitivity of small nanoparticles was studied using surface plasmons in a metallic nanoslit array. When 13nm gold nanoparticles were immobilized on the array, the resonant wavelength and intensity of surface plasmons are substantially changed. Spectroscopic measurements and finite-difference time-domain calculations identified that the surface plasmons in the slit gap had a greater sensitivity than those on the outside surface. Using a nanoslit array with a gap of 50nm, a thickness of 150nm, and a period of 600nm, the authors achieved a detection sensitivity of 1nanoparticle∕μm2 for a 0.2% intensity change.

Inspired by a well-known fact that the magnetic coercivity of a thin film has a strong dependence on its thickness, we have fabricated a 5×60μm and 30nm thick cobalt (Co) strip with thickness modulation along its long axis. The modulation period of 700nm with a depth of 8nm was prepared by a focused ion beam. From magnetic force microscope images, we observed an induced magnetic anisotropy along the short axis of the strip. By comparing out-of-plane magnetoresistance measurements in two magnetic remnant states, we extracted a positive domain wall resistance of 0.03Ω, corresponding to 0.14% magnetoresistance (MR) in a Co thin film.