JP2008181114A - Laminate comprising metal nanoparticle-polymer composite and optical waveguide material - Google Patents

Abstract

To effectively use the plasmon resonance effect of metal nanoparticles, it is necessary to sufficiently combine light and metal nanoparticles. However, in the conventional method, since light passes through the metal nanoparticle layer only once, light is not sufficiently bonded to the metal nanoparticle, so that a signal due to sufficient LPR absorption cannot be obtained.
A laminate comprising a metal nanoparticle-polymer composite and an optical waveguide material, in which a metal nanoparticle-polymer composite layer is laminated on the surface of the optical waveguide material layer, is constructed.
[Selection] Figure 1

Description

  The present invention relates to a laminate comprising a metal nanoparticle-polymer composite and an optical waveguide material, a method for producing the laminate, and a measuring apparatus using the laminate.

With the development of social and economic activities, the importance of optoelectronics that enables large-capacity communication in the fields of information communication and information processing is becoming increasingly important. On the other hand, with further increase in information capacity and speed, information communication / information processing using only existing optical / electronic technology is approaching its limit. Since there is a possibility of overcoming such limitations, surface plasmon resonance technology using metal nanoparticles has attracted attention.

Plasmon is a term of quantum mechanics, which is a plasma wave caused by free electrons in a metal. The plasma wave localized on the surface is called metal surface plasmon. This surface plasmon is a hybrid state of plasma waves and electromagnetic waves, and the wave number is determined by the type of metal, the refractive index near the metal surface, and the like. Normally, surface plasmons on a metal surface do not resonate with light propagating in space, but plasmons on the surface of noble metal nanoparticles cause resonance localized plasmon resonance (LPR) with visible light.

Localized plasmon resonance (LPR) means that plasmons on the surface of metal nanoparticles resonate with light. In the case of a noble metal nanoparticle, resonance occurs in the visible light region, so that transmitted light is colored. The plasmon resonance effect depending on the size of the metal particles is known and described in Non-Patent Document 1 below. For example, in the case of a gold nanoparticle having a particle diameter of 20 nm, an absorption peak appears at 520 nm and is colored red. LPR absorption by metal particles is determined by the type and particle size of metal particles and the dielectric constant in the vicinity of the metal surface. That is, when the refractive index near the metal surface changes, the dielectric constant changes, and the absorption wavelength, absorbance, etc. change. Therefore, it is possible to detect a phenomenon accompanied by a change in refractive index.

An LPR sensor using this fact is proposed in Patent Document 1. By irradiating the substrate on which the metal fine particles are fixed with light and measuring the absorbance of the light transmitted through the metal fine particles, a change in the medium in the vicinity of the metal fine particles is detected. As the metal particles, gold particles and silver particles that exhibit LPR absorption in visible light are mainly used.

LPR induces a strong electric field around the nanoparticles. Near-field optics using this electric field is attracting attention. Further, as a technique for utilizing the interference effect by plasmons, an “optical element and an optical head using the same” shown in Patent Document 2 are disclosed. Further, as a method of using an electric field induced by LPR, “Plasmon Resonance Structure” shown in Patent Document 4 and “Waveguide Element, Spatial Modulator and Time Modulator” shown in Patent Document 5 are disclosed. Yes.

The “optical element and optical head using the optical element” disclosed in Patent Document 3 is an efficient plasmon effect by inserting a layer having an effect of improving surface irregularities as an intermediate layer between conductive films. An amplified optical element with high efficiency and high resolution, and an optical read / write head that enables reading and writing at a scale below the wavelength on the optical disk using the optical element are obtained. As a result, it is possible to record / read linear data density much higher than the linear data density limited by the diffraction limit of light.

In the “plasmon resonance structure” shown in Patent Document 4, a plurality of metal particle layers including nanoparticles or metal domains are formed in a dielectric, and plasmon resonance is performed on the metal particle layer in the thickness direction of the dielectric film. The distance is controlled by the distance and the interval of the metal particles in the direction orthogonal to the thickness direction. For this reason, plasmon resonance control is performed well, and the electric field enhancement effect can be improved.

The waveguide element disclosed in Patent Document 5 includes a waveguide structure in which metal nanoparticles having a uniform size are linearly arranged at equal intervals on a smooth substrate, and metal nanoparticles having different sizes are linearly spaced at equal intervals. The waveguide structures are arranged in multiple stages. The spatial modulation element constituted by this waveguide element selectively couples to the waveguide of metal nanoparticles having different sizes with respect to the frequency of incident light, and propagates plasmons. The time modulation element constituted by the waveguide element uses a fact that the propagation speed of plasmon differs depending on the size of the metal nanoparticle, and gives a time delay to each frequency component of the plasmon.

In order to utilize the LPR of such metal nanoparticles, it is necessary to efficiently couple the metal nanoparticles with light. As in the present invention, as a technique for propagating plasmon energy to the nanometer region, a “near-field light generator and generation method” shown in Patent Document 1, a plasmon propagation mode converter shown in Non-Patent Document 1, There is a plasmon concentrator disclosed in Patent Document 2.

Here, the plasmon propagation mode converter shown in Non-Patent Document 2 is formed on one slope F1 and the upper end of an edge by processing Si into a triangular prism edge structure and coating an Au film. A two-dimensional metal waveguide is used to convert a propagation mode accompanying excitation of a surface plasmon and coupling to a one-dimensional waveguide.

The plasmon concentrator shown in Non-Patent Document 3 has a structure in which minute protrusions are formed in an arc shape on a substrate and are coated with metal. By injecting light into this structure at an angle smaller than the total reflection angle, surface plasmons are excited on the metal surface, and by diffracting and scattering from the metal microstructure, the surface plasmon energy is concentrated locally in the metal waveguide. Combined.

The “near-field light generating device and generating method” disclosed in Patent Document 2 is for thin-line metal, a dielectric disposed on both sides of the metal, a laser device serving as a light source, and laser light irradiation on both sides. Beam splitter and reflector. Then, by exciting surface plasmons on both sides of the fine metal wires by this apparatus, plasmons or Fano modes that are propagated when the fine metal wires are sufficiently thin are generated.

On the other hand, research on optical waveguides has attracted attention as a method for controlling light. The optical waveguide has a structure in which a layer having a high refractive index (core layer) is sandwiched between layers having a low refractive index (cladding layer), and propagates the light confined in the core layer. An example is an optical fiber. A slab optical waveguide (hereinafter sometimes referred to as SOWG) is a flat-type optical waveguide, and a structure using glass or a transparent polymer as a core layer and air as a cladding layer has been studied. ing. In application as a conventional sensor or the like, information on an interface is obtained from intensity change of transmitted light using light of a specific wavelength such as laser light as propagation light. As shown in Patent Document 6, attention is focused on SOWG spectroscopy that simultaneously propagates (white) light in a wide wavelength range from ultraviolet to visible. Features of SOWG spectroscopy include: 1. To selectively measure substances existing near the interface in order to use an electric field (evanescent wave) generated at the interface due to total reflection of light. Because it uses multiple reflection of light, it can be mentioned that it has high sensitivity. The above characteristics make it suitable for in-situ measurement of the absorption spectrum of a substance adsorbed in a trace amount on the interface. Specifically, determination of the adsorption species of the dye on the glass surface, measurement of adsorption isotherm and kinetic investigation, electrode surface The change of the adsorbed species with respect to the electric potential is studied.

JP 2000-356587 A (Patent 3452837) Japanese Patent Application Laid-Open No. 2004-20281 JP 2003-287656 A JP 2006-208057 A JP 2006-293023 A JP-A-8-75639 (Patent 2807777) Fukui and Otsu, “Basics of Optical Nanotechnology” (Ohm) T.A. Yatsui, M .; Kourogi, and M.K. Ohtsu: Appl. Phys. Lett. 79 (2001) 4583 Nomura, Yai, Hoki, Otsu: Proceedings of the 64th JSAP Scientific Meeting, 1p-Q-4

In order to effectively use the plasmon resonance effect of metal nanoparticles, it is necessary to sufficiently combine light and metal nanoparticles. However, in the conventional technique, light passes through the metal nanoparticle layer only once, so that the light is not sufficiently bonded to the metal nanoparticle, so that a signal due to sufficient LPR absorption cannot be obtained.
In Patent Document 2, means such as sputtering and dry etching are used as a method for preparing a sample for utilizing the plasmon resonance effect. The sample of Patent Document 3 is formed by using an ion beam in a vacuum. As a method shown in Patent Document 4, film formation by sputtering is performed. Examples of the production of the waveguide material disclosed in Patent Document 5 include etching using an electron beam, optical lithography, and the like. In these means, a large vacuum device or the like is required. Therefore, it has been demanded that a sample for using the plasmon resonance effect can be easily produced.

In order to achieve the above object, the present inventors have conducted various studies, and as a result, a metal nanoparticle-polymer composite, wherein the metal nanoparticle-polymer composite is immobilized on the surface of the optical waveguide material, and The inventors have reached the invention of a laminate made of an optical waveguide material. That is, the present invention is characterized by constructing a laminate in which metal nanoparticle-polymer composites are laminated on the surface of a slab optical waveguide material.

The present invention relates to a laminate comprising a metal nanoparticle-polymer composite and an optical waveguide material in which a metal nanoparticle-polymer composite layer is laminated on the surface of an optical waveguide material layer.

  In addition, the present invention is characterized in that the metal nanoparticle-polymer composite solution composition is coated on the surface of the optical waveguide material layer, and then laminated by at least drying. The present invention relates to a method for manufacturing a laminate including a molecular complex and an optical waveguide material.

Furthermore, the present invention provides at least a laminate comprising the metal nanoparticle-polymer composite and an optical waveguide material, a light source, means for causing light from the light source to enter the laminate, incident light and / or output. A spectroscopic analyzer for analyzing incident light, and means for introducing light from the laminate into the spectroanalyzer, and analyzing the light emitted from the laminate with the spectroanalyzer, thereby forming metal nanoparticles. It is related with the method of measuring the light absorbency by.

Furthermore, the present invention provides at least a laminate comprising the metal nanoparticle-polymer composite and an optical waveguide material, a light source, means for causing light from the light source to enter the laminate, incident light and / or output. The present invention relates to a spectroscopic analyzer for analyzing incident light and an apparatus for measuring the absorbance of gold nanoparticles, characterized by comprising means for introducing light from the laminate into the spectroscopic analyzer.

A laminate comprising the metal nanoparticle-polymer composite of the present invention and an optical waveguide material can be prepared by a simple technique. By laminating the metal nanoparticle-polymer composite layer on the surface of the slab optical waveguide material, the electric field generated at the interface due to total reflection of SOWG (1) is used, so the substance present near the interface is selected. (2) It is possible to measure the absorption of the metal nanoparticles by LPR with high sensitivity by using the feature that the sensitivity is high because multiple reflection of light is used.
In addition, the energy of incident light can be transmitted to the metal nanoparticles with high efficiency via evanescent light by total reflection.

The outline of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. FIG. 1 shows a laminate comprising a metal nanoparticle-polymer composite and an optical waveguide material, a light source for making light incident on the laminate, and light detection for detecting the intensity of incident light and / or outgoing light. 1 shows an example of a measuring device comprising a measuring instrument and a peripheral electric circuit. FIG. 2 shows an example of a laminate composed of a metal nanoparticle-polymer composite and an optical waveguide material.

The light emitted from the light source 1 is collected by the incident light side condensing optical system 2 and is incident on the laminate 4 made of the metal nanoparticle-polymer composite and the optical waveguide material through the incident light side optical fiber 3. .

An example of the laminate 4 is shown in FIG. A metal nanoparticle-polymer composite 12 is laminated on the surface (bottom surface) of the optical waveguide 11. Incident light 15 is guided into the optical waveguide 11 by the coupling prism 13 and totally reflected at the interface between the optical waveguide 11 and the metal nanoparticle-polymer composite 12. The evanescent light generated at that time is combined with the plasmon resonance of the metal nanoparticles. Outgoing light 16 is emitted by the coupling prism 14.

The light emitted from the laminate 4 is spectroscopically measured by a spectroscope 7 connected by an outgoing light side optical fiber 6. The measured absorption spectrum data of the sample is edited by a computer 8 connected to the spectrometer 7 and displayed as an image.

FIG. 3 shows another example of a laminate 4 made of a metal nanoparticle-polymer composite and an optical waveguide material. Incident light is directly incident on the optical waveguide 11 using the incident light side optical fiber 3. The emitted light is also directly collected by the outgoing light side optical fiber 6 without passing through the coupling prism and connected to the spectrometer 7.

The laminate comprising the metal nanoparticle-polymer composite and the optical waveguide material in the present invention will be described. First, the metal nanoparticle-polymer composite will be described.
The metal nanoparticle-polymer composite in the present invention means a material in which metal nanoparticles having a particle diameter of 1 to 1000 nm are dispersed substantially uniformly in a transparent polymer.

The metal nanoparticle-polymer complex is preferably composed of metal nanoparticles, a polymer that has a function of stabilizing metal particles, and a polymer that interacts.

In the metal nanoparticles, the metal is preferably a metal that causes LPR in the visible light region. Specific examples include noble metals such as gold, silver, copper, and an alloy of gold and silver. Gold is particularly preferable from the viewpoint of ease of production as a nanoparticle and stability.

The particle size of the metal nanoparticles is preferably 1 nm or more, more preferably 2 nm or more, and further preferably 3 nm or more. Moreover, 1000 nm or less is preferable, 100 nm or less is more preferable, and 50 nm or less is more preferable. A particle size smaller than 1 nm is inappropriate because plasmon resonance does not occur. When the particle diameter is larger than 1000 nm, it is difficult to uniformly disperse the metal nanoparticles in the polymer, and plasmon resonance does not occur, which is inappropriate. The particle size is preferably 5 to 20 nm.

The polymer having the function of stabilizing the metal particles is preferably a nitrogen-containing polymer. Specific examples include polyethyleneimine, polyallylamine, polyvinyl pyridine, polyaniline and the like. Of these, polyethyleneimine is particularly preferred.

As a method for producing metal fine particles stabilized by a polymer, there is a method of converting a protective group of a metal colloid protected with a low molecule such as citric acid or tannic acid. Furthermore, metal-containing ions can be produced by reducing metal-containing ions using a reducing agent such as sodium borohydride in the presence of nitrogen-containing polymers, or metal-containing ions can be increased in the presence of nitrogen-containing polymers. There is also a method of reducing by the reducing power of molecules. Among them, by heating the solution containing the nitrogen-containing polymer and the metal-containing ions, using the function of both the polymer having a function of stabilizing the nitrogen-containing polymer and the reducing agent, It is preferable to produce metal fine particles stabilized by a polymer.

The polymer that performs the above-described interaction is preferably a transparent polymer that includes a site that performs the interaction and a site that exhibits hydrophobic properties. Specific examples of the site exhibiting interaction include polyacrylic acid and polymethacrylic acid. Specific examples of the site exhibiting hydrophobic properties include polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate, polystyrene, polyvinyl acetate and the like. Preferably, it is comprised as a copolymer of the site | part which shows interaction, and the site | part which shows a hydrophobic property. For example, polyacrylic acid-polymethyl methacrylate copolymer, polymethacrylic acid-polymethyl methacrylate copolymer and the like can be suitably used.

The solvent of the solution composition containing the metal nanoparticle-polymer composite of the present invention is preferably an aprotic polar organic solvent. In particular, an organic solvent having a donor number of 25 or more is preferable. Specifically, N, N-dimethylformamide (26.6), N, N-dimethylacetamide (27.8), dimethyl sulfoxide (29.8), pyridine (33.1), N-methyl-2 -Pyrrolidone (27.3), ethylenediamine (55), piperidine (51) and the like.

The number of donors is one of the scales representing electron pair donating properties when solvent molecules act as Lewis bases. It is an absolute value when the enthalpy when 10 ⁻³ mol / l of SbCl ₅ reacts with solvent molecules in 1,2-dichloroethane is expressed in units of kcal / mol.

The metal nanoparticle-polymer composite is prepared by a known means, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 2006-8969. Specifically, first, a solution composition containing metal nanoparticles stabilized with a polymer by dissolving a metal salt and a polymer that stabilizes metal particles in a solvent and reducing the metal salt is prepared. Prepare. Next, by mixing the solution composition containing the metal nanoparticles and the polymer solution that interacts, the metal nanoparticles having a structure in which the metal nanoparticles are incorporated into the polymer that interacts with the A solution composition of molecular complex is formed.

In the present invention, the laminate composed of the metal nanoparticle-polymer composite and the optical waveguide material needs to have a layer composed of the metal nanoparticle-polymer composite laminated on the surface of the optical waveguide material. The means for laminating the layer composed of the metal nanoparticle-polymer composite on the optical waveguide material is not particularly limited, but at least after applying the solution composition containing the metal nanoparticle-polymer composite to the surface of the optical waveguide material, It is preferable to laminate the metal nanoparticle-polymer composite on the surface of the optical waveguide material by drying.

Examples of the method for applying the metal nanoparticle-polymer composite solution composition to the surface of the optical waveguide material include a casting method, a dip method, and a spin coating method. Of these, the spin coating method is particularly preferable.

In the lamination of the metal nanoparticle-polymer composite layer, the thickness of the metal nanoparticle-polymer layer can be easily controlled by repeating the coating-drying process a plurality of times and laminating a plurality of layers. It is preferable to laminate two or more times, more preferably four or more times. Stacking a plurality of times is preferable because the thickness of the metal nanoparticle-polymer composite layer is increased and the number of metal nanoparticles combined with evanescent light can be increased. From an economical viewpoint, the number of lamination is preferably 100 times or less, and preferably 50 times or less.

The thickness of the metal nanoparticle-polymer composite layer is preferably 0.01 μm to 100 μm, particularly preferably 0.05 μm to 10 μm.
When the thickness is less than 0.01 μm, there arises a problem that the metal particles in the metal nanoparticle-polymer composite layer cannot be uniformly dispersed. On the other hand, when the thickness exceeds 100 μm, evanescent light does not reach the surface, which causes a problem that there are metal nanoparticles that cannot be used effectively.

The optical waveguide material used in the present invention is not particularly limited as long as it is transparent to incident light. For example, organic or inorganic glass can be used. Although there is no restriction | limiting in particular as thickness of a slab optical waveguide, It is preferable that it is 0.1 micrometer-10 mm. If the thickness of the optical waveguide layer is thinner than 0.1 μm, it does not function as a waveguide, which is not preferable. If the thickness of the optical waveguide layer is greater than 10 mm, multiple reflections in the optical waveguide are small and sufficient evanescent waves are not generated, which is not preferable.

In the present invention, as the coupler for the optical waveguide layer, any type of coupler can be used as long as it can couple light to the slab type optical waveguide. For example, a prism coupler, a grating coupler, or a fiber coupler can be used. Further, as long as light can be coupled to the slab type optical waveguide without using a coupler, a configuration without a coupler may be used.

In the present invention, in addition to the laminate composed of the metal nanoparticle-polymer composite and the optical waveguide material, at least a light source, a means for causing light from the light source to enter the laminate, incident light and / or A measuring apparatus is constructed that includes a spectroscopic analyzer for analyzing the emitted light and a means for introducing light from the laminate into the spectroscopic analyzer.

The light source is not particularly limited as long as it has an intensity that generates an evanescent wave and can be detected by a detector. For example, a semiconductor laser, a solid state laser such as an Nd: YAG laser, a gas laser such as a He—Ne laser, a dye laser, a light emitting diode, a xenon lamp, a halogen lamp, a mercury lamp, or the like can be used. A condensing optical system such as a lens can be used as necessary to make the light from the light source parallel light or to focus the light.

The spectroscopic analyzer is not particularly limited as long as it can spectroscopically analyze light from the light source and absorption due to plasmon resonance. In order to perform the measurement in a short time, a spectroscopic analyzer using a diffraction grating and a photodiode array is particularly preferably used.
If necessary, an incidental electric circuit is installed to control the spectroscopic analyzer and / or record / visualize the measurement result.

The means for causing the light from the light source to enter the laminated body and the means for introducing the light from the laminated body into the spectroscopic analyzer are preferably optical fibers. The use of an optical fiber is preferable because it is easy to make light incident on the optical waveguide material at a specific angle, and the entire apparatus becomes simple.

The present invention also detects the refractive index of a medium in the vicinity of the surface of the metal nanoparticle in the metal nanoparticle-polymer composite immobilized on the surface of the optical waveguide material, for example, up to a distance about the diameter of the metal nanoparticle. Making things possible. Therefore, when the metal nanoparticle-polymer complex is brought into contact with a liquid, the refractive index of the liquid can be measured.

When light is incident on metal nanoparticles such as gold and silver, scattered light and absorption increase at a certain wavelength due to localized plasmon resonance. The resonance wavelength for scattering and absorption depends on the refractive index of the surrounding medium. As the refractive index of the medium around the metal nanoparticles increases, the absorbance at the resonance peak increases and shifts to the longer wavelength side. Therefore, it is possible to detect a change in the refractive index of the medium using the change in absorbance of the metal nanoparticles as a transducer.

Absorbance of the metal nanoparticles is measured by separating the light emitted from the optical waveguide with a spectroscopic analyzer. When the vicinity of the metal nanoparticle-polymer complex is a substance having a high refractive index, the wavelength of LPR absorption by the metal nanoparticle is shifted to a longer wavelength and the absorbance is changed as compared with the case of air. Therefore, the refractive index in the vicinity of the metal nanoparticle-polymer complex can be measured by measuring the absorbance of the metal nanoparticle. Further, by monitoring the absorbance at a specific wavelength, it is possible to detect a change in the refractive index in the vicinity of the metal nanoparticle-polymer complex.
In addition, by entering light having a wavelength corresponding to the LPR of the metal nanoparticles into the optical waveguide, the metal nanoparticles can be excited and the electric field can be enhanced.

A dark red solution is obtained by refluxing a solution prepared by dissolving 1 g of chloroauric (III) acid and 1 g of polyethyleneimine in 1 L of water at 60 ° C. for 2 hours by the method disclosed in JP-A-2006-8969. A composition was prepared. By mixing 100 g of the solution composition with 100 g of a 1% by weight dimethylformamide solution of polymethyl methacrylate-polymethacrylic acid copolymer and further concentrating using a j9 rotary evaporator, gold nanoparticle-polymer composite Dimethylformamide solution composition (solid concentration: 10% by weight, gold concentration in solids: 2.5% by weight, stabilizing polymer: polyethyleneimine, interacting polymer: polymethyl methacrylate-polymethacrylic acid copolymer) Coalescence) was obtained. The above-mentioned solution composition is spin-coated (rotation number: 2500 rpm) once on a glass substrate having a thickness of 1 mm, and dried to form the metal nanoparticle-polymer composite and the optical waveguide material shown in FIG. A laminate was produced.

FIG. 5 shows a visible absorption spectrum when light is irradiated on the laminate composed of the metal nanoparticle-polymer composite and the optical waveguide material using the system shown in FIG. As shown in the figure, absorption due to plasmon resonance of gold nanoparticles was observed at 530 nm. Absorbance by the gold nanoparticles was 0.67.

Metal nanoparticle-polymer composite and light, in which gold nanoparticle-polymer composite solution is spin-coated and dried 1 to 4 times on a glass substrate, and gold nanoparticle-polymer composite layer is laminated several times. A laminate made of a waveguide material was produced. FIG. 7 shows a visible absorption spectrum when the laminated body laminated a plurality of times is irradiated with light in the system shown in FIG. Absorbance increased almost in proportion to the number of laminations, and the absorbance of the gold nanoparticles of the sample laminated four times was 1.7.

FIG. 9 shows the visible absorption spectrum when the laminate composed of the metal nanoparticle-polymer composite and the optical waveguide material is placed in air and in water. When contacted with water, the absorption peak wavelength shifted to the short wavelength side, reflecting the change in the refractive index near the gold nanoparticles on the contact surface.

After immersing a laminate made of a metal nanoparticle-polymer composite and an optical waveguide material in which a gold nanoparticle-polymer composite is formed in a 5 mm square on an optical waveguide material for 1 minute in a 1 M sodium hydroxide aqueous solution. When purified water was added dropwise, it swelled to 20 mm square. Then, the visible light absorption spectrum of the sample heat-treated at 115 ° C. for 10 minutes and dried and fixed on the optical waveguide material is shown in FIG. By performing the swelling-drying treatment, the absorption by the gold nanoparticles changed sharply.
(Comparative example)

As shown in FIG. 4, a visible light absorption spectrum is shown when a gold nanoparticle-polymer composite layer is irradiated with light perpendicularly to a laminate composed of a metal nanoparticle-polymer composite and an optical waveguide material. It is shown in FIG. The absorbance by the gold nanoparticles was 0.019, which was about 1/35 of the absorbance by the optical waveguide of the present invention.

Visible absorption spectrum when a metal nanoparticle-polymer composite and an optical waveguide material laminated multiple times are irradiated with light perpendicularly to the gold nanoparticle-polymer composite layer as shown in FIG. Is shown in FIG. Although the absorbance increases almost in proportion to the number of laminations. Also in the sample laminated four times, the absorbance of the gold nanoparticles was 0.065, which was about 1/26 of the absorbance by the optical waveguide of the present invention.

A laminate comprising the metal nanoparticle-polymer composite of the present invention and an optical waveguide material can be prepared by a simple technique. By laminating the metal nanoparticle-polymer composite layer on the surface of the slab optical waveguide material, the electric field generated at the interface due to total reflection of SOWG (1) is used, so the substance present near the interface is selected. (2) It is possible to measure the absorption of the metal nanoparticles by LPR with high sensitivity by using the feature that the sensitivity is high because multiple reflection of light is used.
In addition, a device that transmits the energy of incident light to the metal nanoparticles with high efficiency via evanescent light by total reflection can be easily constructed.

It is a schematic diagram which shows the structure of the Example by the optical absorption spectrum measuring apparatus using the slab type | mold optical waveguide using the laminated body which consists of a metal nanoparticle-polymer composite of this invention and optical waveguide material. It is sectional drawing which shows an example of the slab type | mold optical waveguide using the laminated body which consists of a metal nanoparticle-polymer composite of this invention, and optical waveguide material. It is sectional drawing which shows an example of the slab type | mold optical waveguide using the laminated body which consists of a metal nanoparticle-polymer composite of this invention, and optical waveguide material. It is sectional drawing which shows an example of the transmitted light measurement which irradiated the light to the metal nanoparticle-polymer composite layer perpendicularly | vertically using the laminated body which consists of a metal nanoparticle-polymer composite and optical waveguide material of this invention. . It is a graph which shows the measurement result of the light absorption spectrum of the slab optical waveguide using the laminated body which consists of a metal nanoparticle-polymer composite of this invention, and optical waveguide material. It is a graph which shows the measurement result of a light absorption spectrum in the transmitted light measurement using the laminated body which consists of a metal nanoparticle-polymer composite of this invention, and an optical waveguide material. It is a graph which shows the measurement result of the light absorption spectrum of a slab optical waveguide in the laminated body which consists of the metal nanoparticle-polymer composite and optical waveguide material which laminated | stacked the metal nanoparticle-polymer composite of this invention in multiple times. . The numbers on the graph indicate the number of stacks. It is a graph which shows the measurement result of the light absorption spectrum in the transmitted light measurement in the laminated body which consists of the metal nanoparticle-polymer composite and optical waveguide material which laminated | stacked the metal nanoparticle-polymer composite of this invention in multiple times. . The numbers on the graph indicate the number of stacks. It is a graph which shows the measurement result of the light absorption spectrum in air | atmosphere and water in the slab optical waveguide using the laminated body which consists of a metal nanoparticle-polymer composite of this invention, and optical waveguide material. It is a graph which shows the measurement result of the light absorption spectrum at the time of performing a swelling-drying process in the slab optical waveguide using the laminated body which consists of a metal nanoparticle-polymer composite of this invention, and an optical waveguide material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Incident light side condensing optical system 3 Incident light side optical fiber 4 Composite which consists of metal nanoparticle-polymer composite and optical waveguide material 6 Outgoing light side optical fiber 7 Spectrometer 8 Computer 11 Optical waveguide material layer 12 Metal Nanoparticle-polymer composite layer 13 Incident light side prism 14 Output light side prism

Claims (4)

  A laminate comprising a metal nanoparticle-polymer composite and an optical waveguide material, wherein the metal nanoparticle-polymer composite layer is laminated on the surface of the optical waveguide material layer.   2. The metal nanoparticle-polymer composite according to claim 1, wherein the metal nanoparticle-polymer composite solution composition is applied on the surface of the optical waveguide material layer and then laminated by at least drying. And a method for producing a laminate comprising an optical waveguide material. A laminate comprising at least the metal nanoparticle-polymer composite according to claim 1 and an optical waveguide material, a light source, means for causing light from the light source to enter the laminate, incident light and / or outgoing light And a means for introducing light from the laminate into the spectrometer, and measuring the light emitted from the laminate to measure the absorbance of the gold nanoparticles. A laminate comprising at least the metal nanoparticle-polymer composite according to claim 1 and an optical waveguide material, a light source, means for causing light from the light source to enter the laminate, incident light and / or outgoing light A device for measuring the absorbance of gold nanoparticles, characterized in that it comprises a spectroscopic analyzer for analyzing the light and means for introducing light from the laminate into the spectroscopic analyzer.

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