Polarized Surface Enhanced Raman and Absorbance Spectra of Aligned Silver Nanorod Arrays

Zhao, Yiping; Chaney, S. B.; Shanmukh, Saratchandra; Dluhy, Richard A.

doi:10.1021/jp057406o

Cited by 142 publications

(159 citation statements)

References 18 publications

Supporting

Mentioning

152

Contrasting

Unclassified

Order By: Relevance

“…7 Polarization dependence of SERS has been investigated for various nanostructures, including nanoparticles, dimers and aggregates of nanoparticles, aligned NWs, and nanorod arrays. [6][7][8][9] Whereas the classical electromagnetic field (EM) theory predicts cos 4 θ dependence, cos 2 θ dependence has been reported in several cases. 7a,9c In summary, we showed that free-standing single-crystalline metal NWs can be synthesized in the vapor phase by an extremely simple method of using a single precursor.…”

mentioning

confidence: 99%

Simple Vapor-Phase Synthesis of Single-Crystalline Ag Nanowires and Single-Nanowire Surface-Enhanced Raman Scattering

et al. 2007

View full text Add to dashboard Cite

We report vapor-phase synthesis of single-crystalline freestanding Ag nanowires (NWs) and polarized surface-enhanced Raman scattering (SERS) of a single NW. To the best of our knowledge, vapor-phase synthesis of single-crystalline Ag NWs and polarized SERS on an individual NW have not yet been reported.Silver has the highest electrical and thermal conductivity among all metals. In addition, because of the nature of its optical constants, silver shows the most effective SERS among all metals in the visible region. 1 Since the intensity of the SERS signal depends strongly on the detailed morphology of the Ag nanostructures, it is most important to have a well-defined and well-characterized system with a clean surface for the preparation of reliable sensors based on SERS detection. Current fabrication processes for the production of SERSactive substrates, however, are often irreproducible to a certain degree, thereby leading to inconsistent optical properties and, thus, significantly fluctuating enhancement factors for substrates prepared by apparently the same procedure. Irreproducible SERS enhancement would be detrimental to quantitative and reliable sensing, which would be most critical for medical diagnosis.As a first step toward fabrication of well-controlled nanobiosensors employing SERS technique, we searched for a method to synthesize well-characterized free-standing single-crystalline Ag NWs with a clean surface. This led us to the adoption of vaporphase synthesis rather than solution phase. While vapor-phase synthesis is one of the most widely used methods for the synthesis of 1D nanostructures, it has been used mainly for the synthesis of semiconductor NWs and nanotubes. Only a few metallic NWs have been synthesized through vapor phase, 2 and most of the reported methods for the synthesis of Ag NWs are wet chemical methods involving templates, surfactants, or capping agents. 3 Our synthetic method is unique in that it uses only a single reactant, Ag 2 O, without using any templates or catalysts. In a typical synthesis, 0.2 g of Ag 2 O powder was placed in an alumina boat in the middle of a 1 in. diameter horizontal quartz tube furnace. The NWs were grown at a few centimeters downstream from the precursor on a Si substrate. At high temperature (T 1 ) 900-1000°C ), the precursor vapor was carried downstream by the flow of 500 sccm of Ar at 5-10 Torr to a lower temperature zone (T 2 ) 500°C), where Ag NWs were grown. The noncatalytic growth of the NWs and the preferred formation of large particles over NWs at higher precursor temperatures demonstrated that the Ag NWs were formed by a vapor-solid mechanism. 2a A representative SEM image in Figure 1a shows good density of straight NWs tens of micrometers long on a Si substrate. The insets are SEM and TEM images of Ag NWs, showing that the tips of NWs are round, and NWs have clean surfaces and diameters of 80-150 nm.The XRD patterns of as-grown NW ensembles (Supporting Information Figure S1) are indexed perfectly to the face-centered cubic (fcc) crystal str...

show abstract

mentioning

confidence: 99%

Simple Vapor-Phase Synthesis of Single-Crystalline Ag Nanowires and Single-Nanowire Surface-Enhanced Raman Scattering

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Here the Raman enhancement was attributed to the high aspect ratio and anisotropic nature of substrate. 11,12 Furthermore, the comb nanostructures Cu lines were etching removed by HNO 3 solution and only low-k dielectrics remained. Comparing to stronger intensities of low-k dielectrics with Cu nanostructures (blue line), the intensities of low-k dielectrics without Cu nanostructures declines by about 80% (red line).…”

Section: Methodsmentioning

confidence: 99%

“…It is known that strong field enhancement generally occurs at the cavities or junction of the basis of nanostructures. 12 When the laser beam source is incident on the Cu comb nanostructure, plasmonic evanescent waves are generated. The evanescent waves propagating toward each other constructively interfere, and the fields within two neighbor Cu lines are enhanced as a result, as shown in Fig.…”

Section: -3 Huangmentioning

confidence: 99%

“…10 While for the aligned high-aspectratio nanowires or nanorods, the maximum enhanced Raman scattering intensity was observed in the polarization direction perpendicular to the long axis of the wires/rods. 11,12 In addition, the SP effect is highly geometry dependent. Generally, highly uniform and periodic nanostructures will greatly improve enhanced Raman scattering.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enhancement of Raman signals from low-k dielectrics with angle-resolved light scattering on nanostructure patterned Cu/low-k interconnects of IC devices

Huang

Liu

Tan

et al. 2015

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

This letter reports the enhancement of Raman signals from low-k dielectric materials in the Cu/low-k interconnects of nanoscale integrated circuit (IC) devices. The Cu nanostructure pattern of the IC device acted as an active substrate for light scattering by the surface plasmon effect, enhancing the Raman signals observed from the low-k dielectric material of the device. The enhancement of the Raman signal of the low-k material was found to be strongly dependent on the incident angle of the incident laser light. A maximally enhanced Raman intensity was achieved when this angle was approximately 45° relative to the surface normal. Our findings are significant to the characterization of low-k materials and the monitoring of low-k reliability in leading edge semiconductor technologies with nanometer-scale structures.

show abstract

“…Silver nanorod arrays were prepared for generating enhanced Raman signals as described previously (6,35). Individual 1-cm by 1-cm substrates or 1-in.…”

Section: Methodsmentioning

confidence: 99%

Detection and Differentiation of Avian Mycoplasmas by Surface-Enhanced Raman Spectroscopy Based on a Silver Nanorod Array

Hennigan

Driskell

Ferguson‐Noel

et al. 2012

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Mycoplasma gallisepticum is a bacterial pathogen of poultry that is estimated to cause annual losses exceeding $780 million. The National Poultry Improvement Plan guidelines recommend regular surveillance and intervention strategies to contain M. gallisepticum infections and ensure mycoplasma-free avian stocks, but several factors make detection of M. gallisepticum and diagnosis of M. gallisepticum infection a major challenge. Current techniques are laborious, require special expertise, and are typically plagued by false results. In this study, we describe a novel detection strategy which uses silver nanorod array-surfaceenhanced Raman spectroscopy (NA-SERS) for direct detection of avian mycoplasmas. As a proof of concept for use in avian diagnostics, we used NA-SERS to detect and differentiate multiple strains of avian mycoplasma species, including Acholeplasma laidlawii, Mycoplasma gallinarum, Mycoplasma gallinaceum, Mycoplasma synoviae, and M. gallisepticum, including vaccine strains 6/85, F, and ts-11. Chemometric multivariate analysis of spectral data was used to classify these species rapidly and accurately, with >93% sensitivity and specificity. Furthermore, NA-SERS had a lower limit of detection that was 100-fold greater than that of standard PCR and comparable to that of real-time quantitative PCR. Detection of M. gallisepticum in choanal cleft swabs from experimentally infected birds yielded good sensitivity and specificity, suggesting that NA-SERS is applicable for clinical detection.

show abstract

Polarized Surface Enhanced Raman and Absorbance Spectra of Aligned Silver Nanorod Arrays

Cited by 142 publications

References 18 publications

Simple Vapor-Phase Synthesis of Single-Crystalline Ag Nanowires and Single-Nanowire Surface-Enhanced Raman Scattering

Simple Vapor-Phase Synthesis of Single-Crystalline Ag Nanowires and Single-Nanowire Surface-Enhanced Raman Scattering

Enhancement of Raman signals from low-k dielectrics with angle-resolved light scattering on nanostructure patterned Cu/low-k interconnects of IC devices

Detection and Differentiation of Avian Mycoplasmas by Surface-Enhanced Raman Spectroscopy Based on a Silver Nanorod Array

Contact Info

Product

Resources

About