High-resolution separation of DNA/proteins through nanorod sieving matrix.

In this paper, we report on an integrated nanorod array as a novel sieving matrix for high-resolution separation of biomolecules. A wide size range of DNA (100 bp-166 kbp) and proteins (11.4 kDa-205 kDa) are resolved into sharp peaks within several minutes using devices with various pore apertures, either in a reptation mode or Ogston mechanism.

Dielectrophoresis-Based Protein Enrichment for a Highly Sensitive Immunoassay Using Ag/SiO Nanorod Arrays.

A nanoscale insulator-based dielectrophoresis (iDEP) technique is developed for rapid enrichment of proteins and highly sensitive immunoassays. Dense arrays of nanorods (NDs) by oblique angle deposition create a super high electric field gradient of 2.6 × 10 V m and the concomitant strong dielectrophoresis force successfully traps small proteins at a bias as low as 5 V.

Metal enhanced fluorescence improved protein and DNA detection by zigzag Ag nanorod arrays.

As metal nano-arrays show great potential on metal enhanced fluorescence (MEF) than random nanostructures, MEF of Ag zigzag nanorod (ZNR) arrays made by oblique angle deposition has been studied for biomolecule-protein interaction and DNA hybridization. By changing the folding number and the deposition substrate temperature, a 14-fold enhancement factor (EF) is obtained for biotin-neutravidin detection. The optimal folding number is decided as Z=7, owing to the high scattering intensity of Ag ZNRs.

Two chiroptical modes of silver nanospirals.

As an emerging three-dimensional chiral metamaterial, plasmonic nanospirals (NSs) possess inherent chiroptical activity that has attracted increasing attention for developing potential photonic applications. However, the study of chiroptical activity of plasmonic NSs is still in its infancy, especially for NSs made of silver, which is a typical plasmonic material with high plasmonic quality. Herein, we present a systematic study of circular dichroism (CD) of silver NSs (AgNSs) that are fabricated and engineered in helical lengths by glancing-angle deposition (GLAD) and dispersed in ethanol.

Tailorable chiroptical activity of metallic nanospiral arrays.

The engineering of the chiroptical activity of the emerging chiral metamaterial, metallic nanospirals, is in its infancy. We utilize glancing angle deposition (GLAD) to facilely sculpture the helical structure of silver nanospirals (AgNSs), so that the scope of chiroptical engineering factors is broadened to include the spiral growth of homochiral AgNSs, the combination of left- and right-handed helical chirality to create heterochiral AgNSs, and the coil-axis alignment of the heterochiral AgNSs. It leads to flexible control over the chiroptical activity of AgNS arrays with respect to the sign, resonance wavelength and amplitude of circular dichroism (CD) in the UV and visible regime.

Microfluidic-based metal enhanced fluorescence for capillary electrophoresis by Ag nanorod arrays.

As metal nanorods show much higher metal enhanced fluorescence (MEF) than metal nanospheres, microfluidic-based MEF is first explored with Ag nanorod (ND) arrays made by oblique angle deposition. By measuring the fluorescein isothiocyanate (FITC) solution sandwiched between the Ag NDs and a piece of cover slip, the enhancement factors (EFs) are found as 3.7 ± 0.

Porosification-reduced optical trapping of silicon nanostructures.

Metal-assisted chemical etching (MACE) was carried out to fabricate solid silicon nanowires (s-SiNWs) and mesoporous silicon nanowires (mp-SiNWs). Total reflection and transmission were measured using an integrated sphere to study optical properties of the MACE-generated silicon nanostructures. Without NW aggregation, mp-SiNWs vertically standing on a mesoporous silicon layer trap less light than s-SiNWs over a wavelength range of 400-800 nm, owing to porosification-enhanced optical scattering from the rough inner surfaces of the mesoporous silicon skeletons.

Au nanoparticle based localized surface plasmon resonance substrates fabricated by dynamic shadowing growth.

Au nanoparticle (NP) substrates, Au NP/TiO(2)/Au NP sandwich structures, and Ti coated Au NP substrates are fabricated by glancing angle deposition (GLAD) and oblique angle deposition (OAD) methods. Under the same deposition condition, the Au NP substrates produced by GLAD are more uniform and reproducible compared to those fabricated by OAD. The localized surface plasmon resonance (LSPR) wavelength of Au NP substrates can be easily tuned by changing the film thickness, the deposition angle, and the coating of the dielectric layer (TiO(2)) and metallic layer (Ti).

Nanorod-mediated surface plasmon resonance sensor based on effective medium theory.

We investigate a nanorod-mediated surface plasmon resonance (SPR) sensor for sensitivity enhancement. The theoretical model containing an anisotropic layer of nanorod is investigated using four-layer Fresnel equations and the effective medium theory. The properties of the nanorod-mediated SPR curves versus the metal thin film thickness d(f), length l, and diameter D of the nanorod are studied in the environment with refractive indices of 1.

An Au/Si hetero-nanorod-based biosensor for Salmonella detection.

We present a novel and effective food-borne bacteria detection method. A hetero-structured silicon/gold nanorod array fabricated by the glancing angle deposition method is functionalized with anti-Salmonella antibodies and organic dye molecules. Due to the high aspect ratio nature of the Si nanorods, dye molecules attached to the Si nanorods produce an enhanced fluorescence upon capture and detection of Salmonella.

Multilayered Si/Ni nanosprings and their magnetic properties.

A two-turn, eight-armed, rectangular Si/Ni heterogeneous nanospring structure on Si(100) has been fabricated using a multilayer glancing-angle deposition technique. The multilayered nanosprings with a height of approximately 1.98 mum were composed of alternating layers of amorphous Si nanorods approximately 580 nm in length and face-centered cubic Ni nanorods approximately 420 nm in length, both with a diameter of approximately 35 nm.