Showing papers on "Surface plasmon resonance published in 1989"
Patent•
10 May 1989
TL;DR: A surface plasmon resonance (SPR) sensor is adapted for biochemical and similar testing on large area samples such as the gel of an electrophoresis apparatus as mentioned in this paper.
Abstract: A surface plasmon resonance (SPR) sensor is adapted for biochemical and similar testing on large area samples such as the gel of an electrophoresis apparatus. The gel is sandwiched between a pair of plates. One of the plates is of transparent material and, sandwiched between itself and the gel is a metal layer of a mosaic of silver dots. Light from a source is directed via a reflector and undergoes total internal reflection at the interfacce between the transparent plate and metal layer. The reflected light is passed via another reflector to a light detector. The equipment is arranged so that SPR occurs at the metal layer, which resonance is critically dependent upon the refractive index of the gel. The structure including the light source and detector, together with reflectors is caused to scan across the gel surface to enable a two-dimensional representation of the changes in refractive index across the gel to be built up. This enables the progress of sequencing to be monitored.
327 citations
Patent•
09 Nov 1989
TL;DR: In this article, the authors describe methods for the production, on metal surfaces, of surface layers which are capable of selective biomolecular interactions; sensing surfaces produced by means of these methods; and the use thereof in biosensors, especially in surface plasmon resonance systems.
Abstract: Methods for the production, on metal surfaces, of surface layers which are capable of selective biomolecular interactions; sensing surfaces produced by means of these methods; and the use thereof in biosensors, especially in surface plasmon resonance systems.
237 citations
TL;DR: In this article, a light is absorbed by the surface plasmon which is not decayed by surface scattering, and the relation between polarizability of a particle and electrical susceptibility does not hold.
Abstract: In an extremely small metallic particle in which electron energies take discrete values, a light is absorbed by the surface plasmon which is not decayed by the surface scattering. The usually used relation between polarizability of a particle and electrical susceptibility does not hold.
100 citations
TL;DR: In this paper, a new type of spatial light modulator has been demonstrated, operating by the surface plasmon resonance effect, using nematic liquid crystal as the active material, and the operation of these devices is 50 times faster than the bulk switching of the liquid-crystal cells.
Abstract: A new type of spatial light modulator has been demonstrated, operating by the surface plasmon resonance effect. Devices have been constructed using nematic liquid crystal as the active material, and the operation of these devices is 50 times faster than the bulk switching of the liquid‐crystal cells. We have obtained resolution of 10–20 μm and contrast ratios better than 100:1.
39 citations
TL;DR: A polarization detector based on the excitation of surface plasmon polaritons on the periodically corrugated metal surface of Schottky structures is presented and by use of two detectors with different grating orientations the polarization of the light can be determined unambiguously.
Abstract: A polarization detector based on the excitation of surface plasmon polaritons on the periodically corrugated metal surface of Schottky structures is presented. The surface modes are only excited by light having the appropriate polarization; they are leaky at the metal-semiconductor interface and are thus radiated into the semiconductor, where they generate charge carriers. By this mechanism the photocurrent of the device is enhanced and depends strongly on the polarization angle of the incident light. By use of two detectors with different grating orientations the polarization of the light can be determined unambiguously.
38 citations
TL;DR: In this paper, a general method to exactly solve the particle-substrate coupling system was presented, and applied to the case of a metallic spherical particle on a thin carbon film.
32 citations
TL;DR: In this article, surface plasmon microscopy (SPM) is used to image external samples with a surface relief structure, which is demonstrated in an experimental coupling setup which combines elements of both the Otto and the Kretschmann configuration.
Abstract: Surface plasmon microscopy (SPM) is used, for the first time, to image external samples with a surface relief structure. This is demonstrated in an experimental coupling setup which combines elements of both the Otto and the Kretschmann configuration. The contrast is shown to be generated between areas of different surface plasmon excitation efficiencies. It is shown that periodic surface structures also can be read‐out in Fourier‐space by surface plasmon diffraction. Finally, Fresnel calculations are presented that demonstrate the contrast improvement achievable by immersion SPM using a suitable liquid.
29 citations
TL;DR: In this article, the authors demonstrate that ultrathin metal coatings can be imaged with high contrast by surface plasmon microscopy, achieving lateral resolution better than 5 μm.
22 citations
TL;DR: In this paper, the results obtained by detecting the bioresponse of the α-Feto protein system and cyclic experiments show that this technique has potential application in the field of biosensing.
Abstract: Biosensing using surface plasmon resonance is experimentally studied. The results obtained by detecting the bioresponse of the α-Feto protein system and cyclic experiments show that this technique has potential application in the field of biosensing. The effects of an organic layer on detecting sensitivity and restoration of sensors are also discussed.
19 citations
TL;DR: In this paper, the deposition and characterization of Langmuir-blodgett films containing the organic semiconductor perylene are described, using a number of techniques, including absorption and fluorescence spectroscopy, surface plasmon resonance and ellipsometry.
18 citations
TL;DR: In this paper, the feasibility of surface plasmon resonance (SPR) for ion sensing has been investigated and a simulation-based optimization of the SP carrying structure is presented.
TL;DR: In this paper, a new theory for the surface plasmon frequency ωSP (k|) dependence on the charge of the electrode was elaborated, and the bending point of the electromodulation plot near p.z.c.
Patent•
05 May 1989
TL;DR: A surface plasmon resonance (SPR) sensor for biochemical and similar testing on large area samples such as the gel of an electrophoresis apparatus is described in this article.
Abstract: A surface plasmon resonance (SPR) sensor for biochemical and similar testing on large area samples such as the gel (10) of an electrophoresis apparatus (13). The gel is sandwiched between a pair of plates (11, 12). Plate (11) is of transparent material and, sandwiched between itself and the gel is a metal layer comprising a mosaic (21) of silver dots. Light from a source (14) is directed via a reflector (16) and undergoes total internal reflection at the interface between plate (11) and metal layer (21). The reflected light is passed via reflector (17) to a light detector (15). The equipment is arranged so that SPR occurs at the metal layer, which resonance is critically dependent upon the refractive index of the gel (10). The structure comprising the light source 14 and detector 15, together with reflectors 16 and 17 is caused to scan across the gel surface to enable a two-dimensional representation of the changes in refractive index across the gel to be built up. This enables the progress of sequencing to be monitored.
TL;DR: In this paper, the surface plasmon resonance in silver particles evaporated onto a dielectric wedge coating a semiconductor substrate layer was studied experimentally and theoretically, and it was shown that the relative enhancement of the second harmonic intensity due to the surface resonance is ∼ 150, what gives an estimate ∼ 2·104 for the analogous contribution to surface enhancement of Raman scattering.
TL;DR: In this paper, Wang et al. used the modified multislice theory to calculate the electron reflection intensity with and without considering the plasmon diffuse scattering in the geometry of reflection high-energy electron diffraction (RHEED).
Abstract: The modified multislice theory [Wang (1989). Acta Cryst. A45, 193-199] has been employed to calculate the electron reflection intensity with and without considering the plasmon diffuse scattering in the geometry of reflection high-energy electron diffraction (RHEED). It has been shown that the inelastic scattering can greatly enhance the reflectance of a surface, depending critically on the incident conditions of the electrons. At some incidences, the inelastic resonance reflection is enhanced, which is considered as the 'true' surface resonance state. This happens within a very narrow angular range (<1 mrad). For 'true' resonance states, the inelastic intensity is much stronger than for other conditions as shown both theoretically and experimentally. The enhancement of the reflection intensity may not be the proper criterion for identifying the 'true' surface resonance. Besides the surface plasmon peaks, an 'extra' peak, located at 4.5 eV, is observed in the reflection electron energy-loss spectroscopy (REELS) study of the 'true' resonance of GaAs (110) surface. This is considered as a characteristic of the resonance propagations of the electrons along the surface and may result from the generation of resonance radiation.
TL;DR: In this paper, the authors derived an expression for the second harmonic generation from metal surfaces under the modified Kretschmann geometry (or Sarid's geometry) based on the hydrodynamic theory of a free electron gas.
TL;DR: The observation of the spatial decay of the long range surface plasmon mode using optical second harmonic generation with asymmetry in the reflected second harmonic profile is reported.
Abstract: We report the observation of the spatial decay of the long range surface plasmon mode using optical second harmonic generation. The surface wave is excited at 1.06 μm with prism coupling in a multilayer geometry consisting of a quartz crystal substrate, a thin silver film, and an index-matched liquid. From the asymmetry in the reflected second harmonic profile a decay length of 0.8 mm is determined. This value is a factor of 3 smaller than that predicted due to the effect of surface roughness scattering on the propagation of the long range surface plasmon mode.
TL;DR: In this article, the self-polarizing contributions to the absorption and elastic scattering properties of a coated sphere are obtained in the large wavelength limit, or dipole approximation, in which the coating is treated as a polarizable, uniaxially anisotropic, shell with the local optic axis directed radially.
Abstract: This project was inspired by the widespread use of the properties of coated spheres in modeling the dielectric and spectroscopic behavior, including surface enhanced Raman spectroscopy, of a variety of dispersed systems. In this paper the self‐polarizing contributions to the absorption and elastic scattering properties of a coated sphere are obtained in the large wavelength limit, or dipole approximation, in which the coating is treated as a polarizable, uniaxially anisotropic, shell with the local optic axis directed radially. Numerical calculations for CO on Ag are provided to illustrate some of the phenomena predicted by the equations. Of particular interest are the dependence of the absorption band for CO stretch upon particle size, surface coverage, and molecular orientation, and the dependence of the surface plasmon resonance absorption on particle size and coverage. Some limitations of the model are examined.
TL;DR: In this paper, the optical absorption spectra of multilayers of the two dyes and of alternate-layer films are repeated, and surface plasmon resonance has also been used to study the linear and non-linear optical properties of these films.
TL;DR: A configuration for the excitation of surface plasmons in the infrared spectral region using ATR but without a coupling prism is presented in this paper, where experiments are performed using an aluminium layer as surface plasmon active material covered by a thin layer of quartz to realize the coupling in the reststrahlen region.
TL;DR: In this paper, the authors studied surface plasmon excitation properties of a mercury-platinum compound showing a negative surface-plasmon dispersion due to the virtual bound states which may exist in such materials.
TL;DR: In this article, the surface plasmon resonance from the metal dielectric constant that increases the local field in the core material was investigated and the frequency of the resonance and the enhancement depend upon the particle shape and the coating thickness, as well as on the specific materials.
Abstract: We study coated, nanometer-size, ellipsoidal particles that have a semiconductor or polymer core surrounded by a metal coating. We predict that composite materials containing these particles will have much larger enhancement of the nonlinear optical response than had previously been found by using semiconductor colloid suspensions or semiconductor - doped glasses. The enhancement is due to the surface plasmon resonance from the metal dielectric constant that increases the local field in the core material. The frequency of the resonance and the enhancement depend upon the particle shape and the coating thickness, as well as on the specific materials. Also, we predict intrinsic optical bistability in these new materials and show that the threshold intensity for optical bistability can be greatly reduced by using the coated particles. We predict a switching intensity of silver coated GaAs particles below 100W/cm2
Patent•
23 Feb 1989
TL;DR: A metal surface carries a coating comprising spacer units, to which haptens are linked as discussed by the authors, which are adapted for use in surface plasmon resonance (SPR) techniques.
Abstract: A metal surface carries a coating comprising spacer units, e.g. protein molecules, to which haptens are linked. These metal surfaces are useful for assays, e.g. in which dissolved haptens in a sample compete with immobilised haptens for binding to antibodies. The coated metal surfaces are adapted for use in surface plasmon resonance (SPR) techniques. Also included are immunoassays in which antibodies are immobilised on the metal surface with hapten conjugates reversibly bound to them, displacement of conjugate, as a result of addition of a sample containing the hapten, being monitored by SPR.
Patent•
13 Dec 1989
TL;DR: In this article, a metal layer with an adjustable selector having effect on the incident angle position of a resonance curve is applied to determine the concentration of one or more than one kind of component in a sample medium simultaneously by difference measurement.
Abstract: PURPOSE: To determine the concentration of one or more than one kind of component in a sample medium simultaneously by difference measurement by applying a metal layer with an adjustable selector having effect on the incident angle position of a resonance curve. CONSTITUTION: A polarized light beam impinges on an incident surface through a prism 2 and repeats total reflection and then the attenuated intensity of outgoing light beam is measured. Incident angle position of a resonance curve is then determined under the influence of variation in the dielectric constant of a test medium 3 near a metal layer 1 caused by the components thereof. More specifically, the metal layer 1 is applied with an adjustable selector having effect on the incident angle position of resonance curve. Since selective coupling can be made and the concentration of one component can be set higher than that of other component, concentration of one or more than one kind of component in the medium 3 can be determined simultaneously by difference measurement.
TL;DR: In this paper, the authors reported the dissociation of supported metal clusters after illumination with low intensity visible laser light and showed that the process is nonthermal and exhibits a resonant dependence on the laser frequency.
Abstract: This paper reports the dissociation of supported metal clusters after illumination with low intensity visible laser light The process is non-thermal and exhibits a resonant dependence on the laser frequency This indicates that a surface plasmon excitation preceeds the dissociation
TL;DR: It is found that plasma waves propagating parallel to the direction of polarization of the radiation fields may be amplified over a relatively narrow range of plasmon wave numbers.
Abstract: Plasmon scattering by electrons in the simultaneous presence of two laser fields is considered. A kinetic equation for the plasmon population is derived, and the rate of change of the plasmon population is calculated. We found that plasma waves propagating parallel to the direction of polarization of the radiation fields may be amplified over a relatively narrow range of plasmon wave numbers.
TL;DR: The optical constants n and k are required for the design of multilayer structures, but little data exist for MO materials, so a method to measure the constants using the surface plasmon resonance phenomenon is developed.
Abstract: Rare-earth–transition-metal thin films are extensively studied as materials for erasable magnetooptical (MO) data storage media. MO Kerr effects can be enhanced by interference effects using multilayer designs. The optical constants n and k are required for the design of multilayer structures, but little data exist for MO materials. We have developed a method to measure the constants using the surface plasmon resonance phenomenon. We measured the constants of TbFe films deposited by rf sputtering. The accuracy estimation was about ±0.005 and could be as good as ±0.001 for optimum conditions.