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Jensen, Traci R.; Kelly, Lance; Lazarides, Anne A.; Schatz, George C.

doi:10.1023/a:1021977613319

Cited by 558 publications

(459 citation statements)

References 15 publications

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“…Extensive theoretical modeling has been performed to provide insight into electromagnetic enhancement by noble-metal nanoparticles (18,19). The simple example of an isolated sphere, with a quasistatic description of the incident electromagnetic field, has been used to derive the proportionality in which E is the electric field magnitude at the surface of the sphere, E 0 is the incident field magnitude, m is the wavelength-dependent dielectric constant of the metal composing the sphere, and 0 is the dielectric constant of the local environment around the sphere (17 ).…”

Section: Fundamental Theorymentioning

confidence: 99%

Surface-Enhanced Raman Spectroscopy

Haynes¹,

McFarland²,

Duyne³

2005

Anal. Chem.

1,072

855

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mekal theoretically predicted inelastic light scattering in 1923 (1). Raman and Krishnan first experimentally observed the phenomenon and reported in their 1928 Nature paper that the inelastic scattering effect was characterized by "its feebleness in comparison with the ordinary scattering" (2). This "feeble" phenomenon is now known as Raman scattering. The change in wavelength that is observed when a photon undergoes Raman scattering is attributed to the excitation (or relaxation) of vibrational modes of a molecule. Because different functional groups have different characteristic vibrational energies, every molecule has a unique Raman spectrum. In accordance with the Raman selection rule, the molecular polarizability changes as the molecular vibrations displace the constituent atoms from their equilibrium positions. The intensity of Raman scattering is proportional to the magnitude of the change in molecular polarizability. Thus, aromatic molecules exhibit more intense Raman scattering than aliphatic molecules.Even so, Raman scattering cross sections are typically 14 orders of magnitude smaller than those of fluorescence; therefore, the Raman signal is still several orders of magnitude weaker than the fluorescence emission in most cases. Because of the inherently small intensity of the Raman signal, the sensitivity limits of available detectors, and the intensity of the excitation sources, the applicability of Raman scattering was restricted for many years. However, its utility as an analytical technique improved with the advent of the laser and the evolution of photon detection technology.In 1977, Jeanmaire and Van Duyne demonstrated that the magnitude of the Raman scattering signal can be greatly enhanced when the scatterer is placed on or near a roughened noble-metal substrate (3). Strong electromagnetic fields are generated when the localized surface plasmon resonance (LSPR) of nanoscale roughness features on a silver, gold, or copper substrate is excited by visible light. When the Raman scatterer is subjected to these intensified electromagnetic fields, the magnitude of the induced dipole increases, and accordingly, the intensity of the inelastic scattering increases. This enhanced scattering process is known as surface-enhanced Raman (SER) scattering-a term that emphasizes the key role of the noblemetal substrate in this phenomenon.

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Section: Fundamental Theorymentioning

confidence: 99%

Surface-Enhanced Raman Spectroscopy

Haynes¹,

McFarland²,

Duyne³

2005

Anal. Chem.

1,072

855

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“…The resonances of a cube have been computed by Fuchs in the electrostatic limit [10], while particles larger than 100 nm have been investigated numerically by different groups [11][12][13]. However, these calculations become very difficult when the particle size is smaller than 100 nm, as extremely rapid variations of the field occur on very short distances [14].…”

Section: Introductionmentioning

confidence: 99%

Influence of the cross section and the permittivity on the plasmon-resonance spectrum of silver nanowires

Kottmann

Martin

2001

Applied Physics B: Lasers and Optics

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We investigate the plasmon resonances for silver nanowires with a non-regular cross section. To study the relationship between the cross section and the spectrum of the plasmon resonances, we consider cross sections evolving from a rectangular shape to a triangular one. In particular, we study the influence of the sharpness of a corner on the near-field enhancement at the vicinity of a particle and discuss its implications for surface-enhanced Raman scattering. We also investigate the influence of the absorption on the plasmon-resonance spectrum and on the near-field enhancement.

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“…The computations were done using a FORTRAN implementation of DDA introduced by Draine and Flatau 21 that has been used for nanoplasmonics calculations by several groups. 7,16,23,24 We calculate the extinction, absorption, and scattering efficiencies, as well as the magnitude of electric field at the site of each dipole, details are given in Refs. 7 and 16.…”

Section: Methodsmentioning

confidence: 99%

“…5 The effects of size, 6 shape, 7 substrate, 8 and plasmon coupling within clusters 9 on the gold LSPR spectrum have been well studied. An excellent review of refractive index sensing using noble-metal NPs can be found in Ref.…”

Section: Introductionmentioning

confidence: 99%

Theoretical proposal for a biosensing approach based on a linear array of immobilized gold nanoparticles

Rafsanjani

Cheng

Mittler

et al. 2010

Journal of Applied Physics

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Non-destructive imaging of an individual protein Appl. Phys. Lett. 101, 093701 (2012) Ultrafast excited state dynamics of spirilloxanthin in solution and bound to core antenna complexes: Identification of the S and T1 states JCP: BioChem. Phys. 6, 08B610 (2012) Ultrafast excited state dynamics of spirilloxanthin in solution and bound to core antenna complexes: Identification of the S* and T1 states J. Chem. Phys. 137, 064505 (2012) Magneto-optic surface plasmon resonance optimum layers: Simulations for biological relevant refractive index changes J. Appl. Phys. 112, 034505 (2012) Additional information on J. Appl. Phys. We propose a sensing mechanism for detection of analytes that can specifically recognized. The sensor is based on closely-spaced chains of functionalized gold nanoparticles ͑NPs͒ immobilized on a waveguide surface, with the signal detected by evanescent waveguide absorption spectroscopy. The localized surface plasmon spectrum of a linear array of closely-spaced, hemispherical gold NPs is calculated using the discrete dipole approximation. The plasmon band is found to broaden to a nanowirelike spectrum when a dielectric coating is put on the particles, and the light polarization is along the NP chain. The origin of this broadening is shown to be the polarization-dependent overlap of the evanescent fields of adjacent NPs upon application of the dielectric coating. These features suggests a mechanism for biosensing with an improved sensitivity compared with traditional NP biosensor methods.

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Cited by 558 publications

References 15 publications

Surface-Enhanced Raman Spectroscopy

Surface-Enhanced Raman Spectroscopy

Influence of the cross section and the permittivity on the plasmon-resonance spectrum of silver nanowires

Theoretical proposal for a biosensing approach based on a linear array of immobilized gold nanoparticles

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