Showing papers on "Surface plasmon resonance published in 1991"
TL;DR: The biospecific interaction of the immobilized ligand with its biological counterpart is illustrated by the effects on the interaction of immunoglobulins with immobilized Staphylococcus aureus protein A for various amounts of protein A.
1,368 citations
TL;DR: An automated biosensor system for measuring molecular interactions has been used to study the kinetics of monoclonal antibody-antigen reactions and found differences in affinity and reaction rates are immediately apparent.
1,114 citations
TL;DR: In this article, a methodology to correlate the absolute surface concentration of protein to the surface plasmon resonance (SPR) response is described, and the thickness and the optical constants for each layer on the sensor chip used were determined with different optical techniques.
1,079 citations
Journal Article•
TL;DR: The development and application of a biosensor-based technology that employs surface plasmon resonance for label-free studies of molecular interactions in real time and the ability to monitor multi-molecular complexes as they form are reported on.
Abstract: We report here the development and application of a biosensor-based technology that employs surface plasmon resonance for label-free studies of molecular interactions in real time. The sensor chip interface, comprising a thin layer of gold deposited on a glass support, is derivatized with a flexible hydrophilic polymer to facilitate the attachment of specific ligands to the surface and to increase the dynamic range for surface concentration measurements. The sensor can be used to measure surface concentrations down to 10 pg/mm2. Typical coefficients of variation are from two to five percent. We anticipate that the ability to monitor multi-molecular complexes as they form will greatly contribute to the understanding of biorecognition and the structural basis of molecular function.
1,012 citations
TL;DR: An integrated fluid handling system used for multichannel biomolecular interaction analysis is described, and experimental results obtained with a theophylline monoclonal antibody as the analyte are compared with a theoretical model.
Abstract: An integrated fluid handling system used for multichannel biomolecular interaction analysis is described. Reactions between biological molecules are monitored in real time by measuring changes in the angular position where surface plasmon resonance occurs at a biospecific active surface. The adsorption efficiency of the analyte onto the biospecific active surface is up to approximately 3%, due to the low channel height, 50 microns, in the flow cell. When a large part of the total biospecific active surface for surface plasmon resonance probing (approximately 0.15 mm2) is used, the sensitivity is high. Sample sizes in the order of 1-50 microL can be injected. The sample zone dispersion is minimized by the low dead volume in the system (approximately 0.4 microL) accomplished by using integrated sample loops and thin conduits. An asset of this integration is the low reagent consumption. The sensor chip with the biospecific active surface is reusable and easily exchanged. Experimental results obtained with a theophylline monoclonal antibody as the analyte are compared with a theoretical model. The standard deviation for the repeatability is approximately 5% typically with 50 microL of 250 pM analyte, and the assay time is 10 min. The detection limit is approximately 10 pg of the analyte on the probed spot of the surface. Possible improvements of the sensitivity and detection limit are discussed.
345 citations
TL;DR: In this article, the use of a dextran layer on the surface of the thin metal film (gold) used for surface plasmon resonance (SPR) is discussed.
Abstract: Research and development work has made surface plasmon resonance (SPR) into an accurate, sensitive and fast method with several bioanalytical applications. The first commercial instrument has also recently been introduced on the market. The present contribution reviews the use of SPR for biospecific interaction analysis and describes a recently developed SPR instrument. Special attention is paid to the use of a dextran layer on the surface of the thin metal film (gold) used for SPR. It is shown that with such a matrix on the surface, the evanescent electric field outside the metal surface is used more efficiently, which improves the analytical performance of the method. Furthermore, the matrix provides a convenient way of covalently binding biomolecules to the sensing surface, thus providing its necessary biospecificity. The chemistry of the coupling matrix is described as well as the optical and liquid-handling systems used. Finally, a few applications of the SPR instrument are demonstrated.
338 citations
TL;DR: In this article, the authors discussed the determination of the thickness and dielectric constant of thin layers by means of surface plasmon resonance and showed that it appears to be impossible to determine these parameters from one single surface-plasmon response experiment.
155 citations
TL;DR: In this article, an indirect surface plasmon resonance (SPR) is used to boost the emission from a fluorescently labelled immunoassay complex at a metal surface, and the potential of the method is demonstrated by assaying for human Chorionic Gonadotrophin (hCG) in serum.
146 citations
Patent•
08 Jun 1991TL;DR: In this paper, a method and apparatus for detecting the presence and/or concentration of biomolecules, in particular DNA, by providing a boundary surface between an optically denser medium and a optically rarer medium is presented.
Abstract: A method and apparatus for detecting the presence and/or concentration of biomolecules, in particular DNA, by providing a boundary surface between an optically denser medium and an optically rarer medium. Biomolecules adsorb to the boundary surface and alter the characteristics of impinging light. The method and apparatus use surface plasmon resonance (SPR) to excite the biomolecules. The angle of incidence of the impinging light is maintained at the angle at which SPR occurs, thereby controlling the energy transferred to the biomolecules. The energy transferred to the biomolecules causes the biomolecules to generate excitation light which is reflected and monitored at the boundary surface. The angle of incidence is controlled by rotating a desk such that the intensity of the reflected light is always maintained at a minimum which ensures that the angle of incidence is equal to the angle at which SPR occurs.
125 citations
TL;DR: In this article, the angular-dependent reflectivity of light falling on a silver-coated prism onto which antibodies are immobilized provides information on the refractive index profile in the immediate vicinity ∼(100 nm) of the interface, which can be interpreted in terms of the coverage of antibodies.
Abstract: In the past few years, much scientific and industrial effort has been put in the development of immunosensors. The utilization of surface plasmon resonance (SPR) has been shown to be a promising method to be implemented in the development of these types of immunosensors. Generally, the angular-dependent reflectivity of light falling on a silver-coated prism onto which antibodies are immobilized provides information on the refractive index profile in the immediate vicinity ∼(100 nm) of the interface, which can be interpreted in terms of the coverage of antibodies; for our purposes, it suffices to mention that in the present context the main experimental parameter of a SPR experiment is the rate of change of angular position of the reflectivity minimum. We focus on the experimental determination of this parameter
72 citations
Patent•
30 Aug 1991TL;DR: A sensor based on the technique of surface plasmon resonance (SPR) comprises an SPR device, a source of electromagnetic radiation from which radiation can be directed onto the device, and a detector to measure the intensity of radiation reflected from the SPR device as mentioned in this paper.
Abstract: A sensor based on the technique of surface plasmon resonance (SPR) comprises an SPR device, a source of electromagnetic radiation from which radiation can be directed onto the device, and a detector to measure the intensity of radiation reflected from the SPR device. The electromagnetic radiation directed onto the SPR device contains both Transverse Electric-polarized and Transverse Electric-polarized components. A polarization analyzer is interposed between the device and the detector such that, at angles away from resonance, little or no light reaches the detector. The sensor is particularly useful in the qualitative and/or quantitative determination of biological, biochemical or chemical analytes.
Patent•
04 Jul 1991
TL;DR: In this article, a surface plasmon resonance (SPR) measurement is carried out at such a wavelength and angle of incidence of the radiation onto the surface that a change resulting from the material concentration accumulated on the opposite side of the material owing to the catalytic properties is detectable in the reflected radiation.
Abstract: In a method for carrying out a surface plasmon resonance (SPR) measurement a beam of electromagnetic radiation is directed through a part transparent to it onto a surface of a material layer having been brought on its opposite side in contact with a test material. A change in the intensity of the reflected radiation, caused by the resonance phenomenon, is utilized for analyzing the test material. The material layer is of catalytic material, for example palladium, having a negative real part of the dielectric constant at the used wavelength of the electromagnetic radiation and being capable of catalyzing chemical reactions in which the test material takes part. The measurement is carried out at such a wavelength and angle of incidence of the radiation onto the surface that a change resulting from the material concentration accumulated on the opposite side of the material owing to the catalytic properties is detectable in the intensity of the reflected radiation.
TL;DR: In this paper, a novel idea of utilizing transition metals in surface plasmon resonance detection has been verified both theoretically and experimentally, and it is shown that the sensitivity of the system depends on the first derivative of the resonance curve (steepness of the slope).
TL;DR: In this article, an inexpensive optical device is described, which is capable of measuring the optical reflectance at different angles, while keeping the laser spot stationary at one point of the surface.
Abstract: In this paper an inexpensive optical device is described, which is capable of measuring the optical reflectance at different angles, while keeping the laser spot stationary at one point of the surface. This is accomplished by applying cylindrical optics. Its use is demonstrated in a surface plasmon resonance (SPR) sensor. A coil-operated vibrating mirror is used to obtain an angle scan of about 4 degrees. The angle of minimum reflectance can be detected with an accuracy of approximately 2 × 10−3 degrees. Despite the use of simple optical components, disturbance of laser beam parallelism is no more than 0.02 degrees. Displacement of the laser spot at the surface during the angle scan is kept within 0.2 mm. The device eliminates disturbances due to surface irregularities in measurements.
TL;DR: In this paper, surface plasmon resonance is applied for sensing concentrations of ammonia in air, using a thin bromo-cresol purple layer as a chemo-optical interface.
Abstract: Surface plasmon resonance is applied for sensing concentrations of ammonia in air, using a thin bromo-cresol purple layer as a chemo-optical interface. The sensor shows a dynamic range of 0.5–15 mbar, a resolution of about 5% and a response time smaller than 1 min.
TL;DR: In this article, the line shape of the plasmon resonance in a cold, small sodium cluster (Na8) is calculated taking into account its coupling to the quantal quadrupole fluctuations of the cluster shape.
Abstract: The line shape of the plasmon resonance in a cold, small sodium cluster (Na8) is calculated taking into account its coupling to the quantal quadrupole fluctuations of the cluster shape. This coupling is found to give rise to a small damping factor (Γ/ħω1∼0.03, where ħω1 denotes the energy centroid and Γ the full width at half maximum of the resonance), and to an asymmetric line shape with Gaussian behaviour in the wings.
TL;DR: Epitaxial CoSi2 particles in a single-crystal silicon matrix are grown by molecular-beam epitaxy using a technique that allows nanometer control over particle size in three dimensions and exhibit resonant absorption predicted by effective-medium theory.
Abstract: Epitaxial CoSi2 particles in a single-crystal silicon matrix are grown by molecular-beam epitaxy using a technique that allows nanometer control over particle size in three dimensions. These composite layers exhibit resonant absorption predicted by effective-medium theory. Selection of the height and diameter of disklike particles through a choice of growth conditions allows tailoring of the depolarization factor and hence of the surface-plasmon resonance energy. Resonant absorption from 0.49 to 1.04 eV (2.5 to 1.2 micron) is demonstrated and shown to agree well with values predicted by the Garnett (1904, 1906) theory using the bulk dielectric constants for CoSi2 and Si.
TL;DR: In this paper, an optically addressed light valve operating on the surface plasmon resonance effect has been developed and tested, which consists of a thin amorphous silicon/liquid crystal sandwich, with an integral silver film to support the surface resonance effect.
Abstract: An optically addressed light valve operating on the surface plasmon resonance effect has been developed and tested. The structure consists of a thin amorphous silicon/liquid crystal sandwich, with an integral silver film to support the surface plasmon mode. The performance characteristics have been measured, and compare favourably with those of conventional liquid crystal light valves.
TL;DR: In this article, the surface plasmon field enhancement through the Kretchmann configuration was exploited to improve the surface sensitivity of the Raman process and achieved a signal-to-noise ratio in excess of 400 with a 600 channel integration time of 400 s in Raman scattering from para-nitrosodimethylaniline at monolayer coverage.
Patent•
06 Nov 1991TL;DR: The transducers for surface plasmon resonance have a support made of gold on whose surface a two-dimensional matrix is produced in the form of a monomolecular organic interlayer and of a ligand or antiligand layer immobilised thereon.
Abstract: The transducer for surface plasmon resonance has a support made of gold on whose surface a two-dimensional matrix is produced in the form of a monomolecular organic interlayer and of a ligand or antiligand layer immobilised thereon. Compared with known transducers with a three-dimensional matrix, the transducer according to the invention can be produced considerably more straightforwardly. For production, a monomolecular layer of alkyl derivatives with sulphur-containing groups is applied to the gold surface by spontaneous chemisorption and subsequently a ligand or antiligand suitable for the required immunological test is immobilised on this layer.
TL;DR: In this paper, it was shown that if the average power per unit area dissipated on the metal film exceeds approximately 1 mW mm−2, then the coupling gap and the surface plasmon resonance are noticeably altered.
Abstract: Using the Otto (prism-air gap-sample) configuration p-polarized light of wavelength 632·8 nm has been coupled with greater than 80% efficiency to surface plasmons on the aluminium electrode of silicon-silicon dioxide-aluminium structures. The results show that if the average power per unit area dissipated on the metal film exceeds approximately 1 mW mm−2, then the coupling gap and thus the characteristics of the surface plasmon resonance are noticeably altered. In modelling the optical response of such systems the inclusion of both a non-uniform air coupling gap and a thin cermet layer at the aluminium surface may be necessary.
TL;DR: The optical extinction spectra of ETA-coated silver bromide nanoparticles have been shown to shift to shorter wavelengths with longer exposure times, consistent with theory so long as the coat thickness increases as discussed by the authors.
Abstract: Silver bromide nanoparticles exposed briefly to intense UV light in the presence of ethylenediaminetetraacetic acid (EDTA) have optical extinction spectra similar to those computed for distributions of silver‐coated silver bromide nanoparticles. With longer exposure times the plasmon resonance maximum is shifted to shorter wavelengths, a result consistent with theory so long as the coat thickness increases with exposure to light. The resonance maximum of the distribution of coated particles can be controllably shifted from 400 up to 700 nm.
TL;DR: In this article, a surface plasmon immunosensor was developed to detect antibody and antigen immunoresponse, and the experimental results of sensor sensitivity, the real-time measurements and the problem of repeated utilization of the sensors are evaluated using α-Feto-protein (α-FP) and goat IgG.
Abstract: A surface plasmon is a charge density wave propagating along the interface between a metal on dielectric medium. Since the energy is concentrated at the interface, sensors that utilize the surface plasmon are extremely sensitive to both the charges in the dielectric properties and the geometry of the interface.
A surface plasmon immunosensor to detect antibody and antigen immunoresponse has been developed. Here the sensitivity of the sensor is theoretically investigated and the experimental results of sensor sensitivity, the real-time measurements and the problem of repeated utilization of the sensors are evaluated using α-Feto-protein (α-FP) and goat IgG. In addition, the problem of deciding whether to use antibody or antigen as immobilized sensing medium is discussed based on the characteristics of surface plasmon and biomolecules. As a result, it is concluded that with an antigen immobilized sensor, the sensitivity is higher and the real-time response can be detected.
Patent•
30 Aug 1991TL;DR: A sensor based on the technique of surface plasmon resonance (SPR) comprises a SPR device (1, 2, 3), a source (4) of electromagnetic radiation from which radiation can be directed onto the device, and a detector (9) to measure the intensity of radiation reflected from the SPR device as discussed by the authors.
Abstract: A sensor based on the technique of surface plasmon resonance (SPR) comprises a) an SPR device (1, 2, 3), b) a source (4) of electromagnetic radiation from which radiation can be directed onto the device, and c) a detector (9) to measure the intensity of radiation reflected from the SPR device. The electromagnetic radiation directed onto the SPR device contains both TE-polarised and TM-polarised components and a polarisation analyser (8) is interposed between the device and the detector such that, at angles away from resonance, little or no light reaches the detector. The sensor is particularly useful in the qualitative and/or quantitative determination of biological, biochemical or chemical analytes.
TL;DR: The optical absorption spectrum around the surface plasmon peak for K21+ was presented in this article, where hot, charged potassium clusters were produced by an adapted liquid metal ion source.
Abstract: The optical absorption spectrum around the surface plasmon peak is presented for K21+. Hot, charged potassium clusters are produced by an adapted liquid metal ion source. The plasmon is found to be slightly red shifted from and distinctly broader than the one reported in an experiment on colder clusters by Brechignac et al. [3]. Mechanisms responsible for the temperature dependence of the width and position of the surface plasmon in small metal clusters are discussed.
01 Jan 1991
TL;DR: This chapter on surface effect immunoassays is written with a (slightly) futuristic view on what the authors consider will be the next generation of technology to be applied successfully to the measurement of antibodies or antigens for clinical purposes.
Abstract: This chapter on surface effect immunoassays is written with a (slightly) futuristic view on what we consider will be the next generation of technology to be applied successfully to the measurement of antibodies or antigens for clinical purposes. This is a relatively new field based on well established physical principles ( for a general review of this area see reference 1).
08 Mar 1991
TL;DR: In this article, the authors proposed a method to provide a device having a wide dynamic range by magnifying a polarized light flux, converging the magnified light flux and projecting it on the surface of a sample coming into contact with a light wave connector through a metallic thin film, and detecting the reflected light spatially.
Abstract: PURPOSE: To provide a device having a wide dynamic range by magnifying a polarized light flux, converging the magnified light flux, projecting it on the surface of a sample coming into contact with a light wave connector through a metallic thin film, and detecting the reflected light spatially. CONSTITUTION: The light from a laser 1 is magnified once in a diameter of a light flux by means of the first, the second and the third lenses 5, 11 and 12, and next, it is converged on a sample 10, and thereby, a small spot diameter or a wide incident angle range can be obtained. Surface plasmon is excited on the interface between the sample 10 and a metallic thin film 3 due to incidence of the light. The reflected light is received as it is by means of an image sensor 8, and a position of a spatial incident light beam on the sensor 8 shows an incident angle upon the surface of the sample 10. An output from the sensor 8 is converted digitally, and is taken into a calculator, and a resonance angle is found. The sample 10 is moved by means of an X-Y stage 9, and a refraction factor or two-dimensional distribution of the film thickness can be also determined. COPYRIGHT: (C)1993,JPO&Japio