WO2019146692A1 - Substrat d'analyse - Google Patents

Substrat d'analyse Download PDF

Info

Publication number
WO2019146692A1
WO2019146692A1 PCT/JP2019/002253 JP2019002253W WO2019146692A1 WO 2019146692 A1 WO2019146692 A1 WO 2019146692A1 JP 2019002253 W JP2019002253 W JP 2019002253W WO 2019146692 A1 WO2019146692 A1 WO 2019146692A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal
film
particles
substrate
metal film
Prior art date
Application number
PCT/JP2019/002253
Other languages
English (en)
Japanese (ja)
Inventor
啓 篠塚
紘太郎 大
匠悟 三浦
Original Assignee
王子ホールディングス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 王子ホールディングス株式会社 filed Critical 王子ホールディングス株式会社
Publication of WO2019146692A1 publication Critical patent/WO2019146692A1/fr

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/65—Raman scattering
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64—Fluorescence; Phosphorescence

Definitions

  • the present invention relates to a substrate for analysis.
  • Priority is claimed on Japanese Patent Application No. 2018-010683, filed January 25, 2018, the content of which is incorporated herein by reference.
  • Raman spectroscopy has a very low intensity of Raman scattered light. It is considered to use surface enhanced Raman scattering (SERS) for the improvement.
  • SERS is a phenomenon in which the intensity of Raman scattered light of a molecule to be measured adsorbed is significantly enhanced by the electric field enhancement by surface plasmon resonance on a metal surface such as Au or Ag.
  • the use of electric field enhancement by surface plasmon resonance is also considered in optical analysis methods other than Raman spectroscopy and infrared absorption spectroscopy and fluorescence spectroscopy.
  • the signal amplification apparatus for Raman spectroscopy analysis provided with a metal film provided with a metal film (patent document 1).
  • An electric field enhancing element including a metal layer, a dielectric layer provided on the metal layer, and a plurality of metal particles provided on the dielectric layer, wherein the plurality of metal particles are It has a periodic arrangement capable of exciting propagating surface plasmons propagating through the interface between the metal layer and the dielectric layer, and the propagating surface plasmons and localized surface plasmons excited by the metal particles are electromagnetic. Interact with each other, and the resonance wavelength of each surface plasmon is different, and in the spectrum of the reflected light when the electric field enhancing element is irradiated with white light, the half bandwidths of the first absorption region and the second absorption region satisfy a specific relationship.
  • An electric field enhancing element in which the wavelength of excitation light of the electric field enhancing element is included in the range of the second absorption region Patent Document 2.
  • the device of Patent Document 1 utilizes propagating surface plasmons, and thus has the advantage that the variation of the electric field distribution on the nano-periodic structure is small, but the enhancement effect is due to the electric field enhancement solely by the propagating surface plasmons. Has the disadvantage of being low.
  • the electric field enhancing element of Patent Document 2 the propagating surface plasmon and the localized surface plasmon are combined, the electric field distribution is homogenized by the propagating surface plasmon, and the localized electric surface plasmon is enhanced. By doing this, it is a configuration that combines the advantages of the propagation type and the localized type, and it is possible to achieve both uniformity and strength to some extent.
  • the molecule to be measured of the sample can not approach the metal film surface with the highest electric field enhancing effect of the propagating surface plasmon.
  • the metal particles are arranged in the arrangement necessary for exciting the propagating surface plasmon, the distance between the particles is required to utilize the electric field enhancement utilizing the gap between the metal particles having a large effect as the localized surface plasmon. Too large is also mentioned as a disadvantage.
  • An object of the present invention is to provide a substrate for analysis which can carry out optical analysis with high sensitivity utilizing electric field enhancement by surface plasmon resonance.
  • An analytical substrate comprising: [2] The analytical substrate of [1], wherein the two-dimensional lattice structure is a triangular lattice structure or a square lattice structure.
  • a plurality of the metal films are provided in the form of island-like gaps having a length of 1 ⁇ m or less in the major axis direction in the metal film, and a plurality of metal is not present and the first surface of the substrate is exposed
  • the present invention it is possible to provide an analytical substrate capable of highly sensitively performing optical analysis utilizing electric field enhancement by surface plasmon resonance.
  • the clear difference from Patent Document 2 is that, in the present invention, the measurement target molecule of the sample can approach the metal film surface with the highest electric field enhancing effect of the propagating surface plasmon. Because of this difference, the present invention is superior to the prior art in the enhancement effect of Raman scattered light.
  • FIG. 5 is a partial cross-sectional view schematically showing a IV-IV cross-section in FIG. 4 (however, illustration of metal nanoparticles is omitted). It is a scanning electron microscope image of the board
  • FIG. 1 is a cross-sectional view schematically showing an analysis substrate according to a first embodiment of the present invention.
  • FIG. 2 is a top view schematically showing an analysis substrate according to an example of the present embodiment.
  • FIG. 3 is a perspective view of the analysis substrate shown in FIG. However, the illustration of the metal nanoparticles is omitted in FIGS.
  • the analysis substrate 10 of the present embodiment includes a substrate 1, a metal film 3 provided on the first surface 1 a of the substrate 1, and a plurality of metal nanoparticles 5 dispersed on the metal film 3.
  • the first surface 1a of the substrate 1 has a two-dimensional lattice structure.
  • the metal film 3 is formed along the first surface 1a. Therefore, the surface of the metal film 3 provided on the first surface 1a also has a two-dimensional lattice structure.
  • the metal film 3 and the plurality of metal nanoparticles 5 are in contact with each other.
  • the substrate 1 At least the first surface 1a of the substrate 1 is made of a dielectric or a semiconductor.
  • the substrate 1 may be, for example, a substrate made of a dielectric or a semiconductor, and two or more of the conductor layer, the dielectric layer, and the semiconductor layer may be stacked such that the first surface is a dielectric or a semiconductor. It may be a multilayer substrate.
  • the dielectric or semiconductor is not particularly limited, and may be a known material in applications such as a substrate for analysis.
  • a substrate made of only a dielectric or a semiconductor is used as the substrate 1 and, for example, a quartz substrate, various glass substrates such as alkali glass and non-alkali glass, sapphire substrate, silicon (Si) substrate, silicon carbide Examples include substrates made of inorganic substances such as SiC), and substrates made of organic substances such as polymethyl methacrylate, polycarbonate, polystyrene, polyolefin resin, and polyester resin.
  • the thickness of the substrate 1 is not particularly limited, and may be, for example, 0.1 to 5.0 mm. The thickness of the substrate 1 is measured by a general caliper measurement method established in JIS B7507.
  • the two-dimensional lattice structure of the first surface 1 a is for providing a two-dimensional lattice structure on the surface of the metal film 3, and is set according to the desired two-dimensional lattice structure on the surface of the metal film 3.
  • the metal constituting the metal film 3 may be any metal that can generate electric field enhancement by surface plasmon resonance, and examples thereof include gold, silver, aluminum, copper, platinum, alloys of two or more of these, and the like.
  • the sheet resistance of the surface of the metal film 3 at 25 ° C. (hereinafter, “sheet resistance of the surface at 25 ° C.” may simply be referred to as “sheet resistance of the surface”) is 5000 ⁇ / ⁇ or less, and 3 to 5000 ⁇ . / ⁇ is preferable, 3 to 500 ⁇ / ⁇ is more preferable, and 3 to 300 ⁇ / ⁇ is the most preferable.
  • the sheet resistance of the surface of the metal film 3 being equal to or less than the upper limit value indicates that the metal film 3 is a continuous film. When the sheet resistance of the surface of the metal film 3 is within this range, the metal film 3 is not completely divided even though it has nanogaps due to the non-film formation region G described later.
  • the sheet resistance of the surface of the metal film 3 is less than or equal to the above upper limit value because the distance between the metal surfaces 3 a facing each other via the non-film formation region G is In the range of 1 to 20 nm, more specifically in the range of 1 to 10 nm, and more specifically in the range of 1 to 5 nm.
  • the metal film 3 is a discontinuous film (for example, one composed of a plurality of metal films dispersed in an island shape), the sheet resistance of the surface does not become 5000 ⁇ / ⁇ or less.
  • the sheet resistance ( ⁇ / ⁇ ) of the surface of the metal film 3 is a value at 25 ° C. Specifically, the sheet resistance is the electrical resistance ( ⁇ ) when current flows from one end to the opposite end of a square area of any size on the surface of the metal film 3 under the condition of 25 ° C. . The details are as shown in Examples described later.
  • the metal film 3 has a two-dimensional lattice structure that follows the first surface 1 a of the substrate 1.
  • “follow” means that the position of the convex portion or the concave portion in the two-dimensional lattice structure on the surface of the metal film 3 substantially coincides with the position of the convex portion or the concave portion in the two-dimensional lattice structure of the first surface 1 a of the substrate 1 Indicates that.
  • the “two-dimensional lattice structure” is a periodic uneven structure in which a plurality of convex portions or concave portions are periodically arranged in two dimensions. Two-dimensionally arranged indicates that the plurality of convex portions or concave portions are arranged in two or more directions. Note that a periodic uneven structure in which a plurality of projections or depressions are periodically arranged in one dimension is also referred to as a one-dimensional lattice structure. The arrangement in one dimension indicates that the arrangement direction of the plurality of projections or depressions is one direction.
  • the propagation type surface plasmon of the metal surface is a surface electromagnetic field accompanied by a compressional wave of free electrons generated by light (excitation light such as a laser used in Raman spectroscopy) incident on the metal surface.
  • light excitation light such as a laser used in Raman spectroscopy
  • the metal surface is flat, propagating surface plasmon resonance is not induced because the dispersion curve of the surface plasmon present on the metal surface does not cross the dispersion line of light.
  • the dispersion straight line of light (diffracted light) diffracted by this periodic uneven structure intersects with the dispersion curve of the surface plasmon, and the propagating surface plasmon resonance is induced .
  • the periodic uneven structure is a one-dimensional lattice structure (for example, a line and space structure in which a plurality of grooves (concave portions) or convex lines (convex portions) are arranged in parallel).
  • Optical analysis using electric field enhancement by surface plasmon resonance can be performed more sensitively than in some cases.
  • a tetragonal lattice structure in which the arrangement direction is two directions and the crossing angle is 90 °, and the arrangement direction is three directions and the crossing angle is 60 ° also referred to as a hexagonal lattice.
  • the shape of the convex portion constituting the two-dimensional lattice structure is, for example, a cylindrical shape, a conical shape, a truncated cone shape, a sine wave shape, a hemispherical shape, a substantially hemispherical shape, an ellipsoidal shape, or a derivative shape based on them It may be.
  • the shape of the concave portion constituting the two-dimensional lattice structure may be, for example, a shape obtained by inverting the shape of the convex portion mentioned above.
  • a triangular lattice structure is preferable because it can induce propagating surface plasmon resonance with higher efficiency.
  • the two-dimensional lattice structure of the surface of the metal film 3 is a triangular lattice structure constituted of a plurality of truncated cone-shaped convex portions 3c as shown in FIGS.
  • the height of the convex portion 3c is preferably 15 to 150 nm, and more preferably 30 to 80 nm. If the height of the convex portion 3c is equal to or more than the lower limit value of the above range, the two-dimensional lattice structure on the surface of the metal film 3 sufficiently functions as a diffraction grating, and propagation type surface plasmon resonance can be induced.
  • the metal film 3 tends to be a continuous film. Also in the case where the convex portion 3c has another shape, the preferable height is approximately the same.
  • the two-dimensional lattice structure on the surface of the metal film 3 is composed of a plurality of recesses, the preferred depth of the recesses is approximately the same as the preferred height of the protrusions 3c. Precisely, the optimum value of the height of the convex portion 3c is determined by the volume fraction and the dielectric constant of the convex portion 3c which interacts with the electromagnetic field by the surface plasmon.
  • the height of the convex portion 3c is the distance in the vertical direction to the average value of the top surfaces of the truncated cones of the three convex portions starting from the central point equidistant from the adjacent three convex portions as AFM (atomic force microscope Measured by) etc.
  • AFM atomic force microscope Measured by
  • AFM images of 5 ⁇ m ⁇ 5 ⁇ m are acquired for these five measurement regions, and the above-mentioned three-point center depths of nine locations randomly measured for each AFM image are measured. Since the AFM probe may generate anisotropy in the image depending on the scan direction, as shown in Fig.
  • the length measurement is performed by creating profile images in three directions D M1 to D M3 and in each direction Perform at three measurement points, for a total of nine measurement points.
  • the average value of the measured values obtained at the nine measurement points is taken as the measured value of one measurement area, the measured values of the five measurement areas are similarly determined, and the average of the measured values of the five measurement areas is calculated.
  • the height of the projection 3c is obtained.
  • Each of D M1 to D M3 is a direction substantially orthogonal to each of the three arrangement directions E M1 to E M3 of the convex portions 3 c on the main surface of the metal film 3 (Because the actual lattice arrangement has some distortion, Not necessarily orthogonal).
  • the heights of the projections of the other shapes and the depths of the recesses are also measured by the same measurement method.
  • the pitch ⁇ of the convex portions 3c in the arrangement direction of the convex portions 3c is designed to correspond to the wavelength ⁇ i of the incident light (excitation light).
  • the real part of the relative dielectric constant of metal at k i is ⁇ 1
  • the real part of the relative dielectric constant of the specimen is ⁇ 2 .
  • the metal forming the convex portion 3c is gold (Au)
  • the sample is a dried organic substance ( ⁇ 2 2.22.25)
  • k spp 16.6 ⁇ m ⁇ 1
  • ⁇ 438 nm It is.
  • the convex portions 3c may be fabricated as close as possible to the pitch ⁇ .
  • the two-dimensional lattice arrangement is a square lattice or one-dimensional lattice arrangement (line and space)
  • the following equation 3 may be used instead of the equation 2.
  • Laser light sources used as incident light include ones corresponding to various wavelengths such as 785, 633, 532, 515, 488, and 470 nm.
  • gold Au
  • a light source larger than the wavelength of about 500 nm and a light source smaller than the wavelength about 500 nm or so as a metal species constituting the sea-island structure, metal nanoparticles and periodic uneven structure.
  • silver Au
  • metal enhanced species other than gold (Au) and silver (Ag) may be able to obtain the surface enhanced Raman scattering effect, which is not necessarily limited to the above.
  • the preferred pitch is the same as in the case where the projections 3c have other shapes.
  • the preferred pitch of the recesses in the arrangement direction of the recesses is the same as the preferred pitch of the protrusions 3c.
  • the pitch of the convex portions 3c is obtained by measuring the horizontal distance between the center points of two adjacent truncated conical projections by AFM (atomic force microscope) or the like. For measurement, five two-dimensional lattice structure surfaces separated by 100 ⁇ m or more are used. AFM images of 5 ⁇ m ⁇ 5 ⁇ m are acquired for these five measurement regions, and the distance between the two points of nine locations randomly extracted for each AFM image is measured. Since the AFM probe may cause anisotropy in the image depending on the scan direction, as shown in Fig. 2, the profile image is created in three directions E M1 to E M3 as shown in FIG. Perform at 9 points in total.
  • AFM atomic force microscope
  • the average value of the measurement values obtained at the nine measurement points is taken as the measurement value of one measurement area, and the average of the measurement values of the five measurement areas is determined to obtain the pitch of the convex 3c.
  • the pitches of convex portions of other shapes and the pitches of concave portions are also measured by the same measurement method.
  • Aspect A A plurality of non-film-forming areas provided as an island-like gap shape having a length of 1 ⁇ m or less in the major axis direction in the metal film and the first surface 1a of the substrate 1 is exposed without metal Metal film with.
  • Aspect B a metal film not having the non-film formation region.
  • the metal film 3 is a metal film of aspect A (hereinafter, also referred to as a metal film 3A), the combined use of the propagating surface plasmon and the enhanced electric field by the localized surface plasmon, or the propagating surface plasmon and the localized surface Optical analysis can be performed more sensitively by utilizing resonance coupling (coupling) of enhanced electric fields by plasmons.
  • the metal film 3 is a metal film of aspect B (hereinafter, also referred to as a metal film 3B)
  • optical analysis can be performed with higher sensitivity by utilizing an enhanced electric field by propagating surface plasmons.
  • FIG. 4 is an enlarged top view schematically showing the surface on the metal film 3 side of the analysis substrate 10 when the metal film 3 is the metal film 3A
  • FIG. 5 is an IV in FIG. 4 of this analysis substrate.
  • FIG. 4 is a partial cross-sectional view schematically showing a cross-section of FIG. However, in FIGS. 4 to 5, the illustration of the metal nanoparticles is omitted.
  • the metal film 3A has a plurality of non-film formation regions G.
  • the plurality of non-film formation regions G are dispersedly provided in the metal film 3A as an island-like gap shape whose length in the long axis direction is 1 ⁇ m or less.
  • a region other than the non-film formation region G of the metal film 3 is a film formation region.
  • the non-film formation region G is a region in which the first surface 1 a is exposed without the presence of metal. That is, it is a gap (gap) penetrating the metal film 3A in the thickness direction.
  • a region (for example, a region S in FIG. 5) which is not a void penetrating the metal film 3A even if metal does not exist in a part in the thickness direction does not correspond to the non-film formation region G. It is a film formation area.
  • the non-film formation area G is an island-shaped gap in a top view, and the plurality of non-film formation areas G may be independent of one another or may be several in number. Absent. Therefore, as shown in FIG. 5, the non-film formation area G is surrounded by the metal surface 3a, and the metal surfaces 3a face each other through the non-film formation area G.
  • the distance between the metal surfaces facing each other through the non-film formation area G, that is, the width of the non-film formation area G is usually extremely small, for example, on the order of several nanometers to several tens of nanometers. Between such metal surfaces 3a, electric field enhancement can be generated by superposition of electric fields by localized surface plasmons. In particular, when the width of the non-film formation region G is one digit nanometer, extremely strong electric field enhancement is obtained.
  • the distance between the metal surfaces 3a facing each other through the non-film formation region G is preferably 1 to 20 nm, more preferably 1 to 10 nm, and still more preferably 1 to 5 nm. If the distance between the metal surfaces 3a is within the above range, the electric field enhancing effect by localized surface plasmon resonance is more excellent.
  • the metal surface surrounding the non-film formation region G is an inclined surface inclined with respect to the thickness direction of the metal film 3 as shown in FIG. 5, there is a distribution in the distance between the metal surfaces 3a.
  • the maximum value of the distance between the metal surfaces 3a is below the said preferable upper limit.
  • the minimum value of the distance between the metal surfaces 3a is more than the said preferable lower limit.
  • the distance between the metal surfaces 3a is measured by the method described in the examples to be described later.
  • the thickness of the metal film 3A is preferably 3 to 40 nm, more preferably 4 to 30 nm, and most preferably 5 to 20 nm as the average thickness of the region other than the non-film formation region G, ie, the film formation region. If the thickness of the metal film 3A is within the above range, the non-film formation region G is provided, and the distance between the metal surfaces opposed via the non-film formation region G, the non-film formation region with respect to the total area of the metal film 3A It tends to become the metal film 3A in which the ratio of the area of G is within the above preferable range. If the thickness of the metal film 3A is equal to or more than the lower limit value, the sheet resistance of the surface of the metal film 3A is likely to be equal to or less than the upper limit value.
  • the thickness of the metal film 3A (average thickness of the film formation region) is a value calculated from the film formation rate obtained by the following method. First, a flat substrate such as a single crystal silicon substrate or the like and having a center line average roughness Ra of 1 nm or less obtained by atomic force microscope (AFM) is prepared, and is masked with a tape etc. After forming a film for a fixed time of about several tens of nm and removing the mask, the film thickness is measured by AFM. From the above information, the deposition rate (deposition thickness per unit time (nm / min)) is determined. Once the film formation rate is determined, the thickness of the metal film 3A can be calculated from the film formation rate and the film formation time for forming the metal film 3A.
  • AFM atomic force microscope
  • the thickness of the film may be measured using a stylus type profilometer instead of AFM. In this case, similar results can be obtained, but in the case where the measurement values by the AFM and the stylus type profilometer differ, in the present invention, the measurement values by the AFM are adopted.
  • the thickness of the metal film 3A for convenience, a microscopic image of a cross-sectional sample of the substrate including the metal film 3A is acquired using a transmission electron microscope (TEM), and the thickness of the metal film 3A is measured in the image. It may be measured by a method. Similar results are obtained in this case as well. Since this method does not need to measure information such as the film formation rate in advance, this method is an effective means for samples whose manufacturing conditions and the like are unknown.
  • an extremely thin scratch is formed on the surface of the metal film 3A using a knife or the like, and the depth of the scratch is measured by AFM.
  • the method of lengthening is effective. Since the metal film 3A is extremely thin, it is possible to form a scratch in which the substrate is exposed with a relatively weak force.
  • the thickness of the metal film 3B is more preferably 40 to 400 nm or less, further preferably 50 to 200 nm. If the thickness of the metal film 3B is equal to or more than the above lower limit value, it tends to be a metal film having no non-film formation region. If the thickness of the metal film 3BA is within the above range, the sheet resistance of the surface of the metal film 3A is likely to be within the range. The thickness of the metal film 3B is measured in the same manner as the thickness of the metal film 3A.
  • the metal constituting the metal nanoparticles 5 may be any metal as long as it can generate electric field enhancement by surface plasmon resonance, and examples thereof include gold, silver, aluminum, copper, platinum, alloys of two or more of these, and the like.
  • the shape of the metal nanoparticles 5 is not particularly limited, and may be, for example, spherical, needle-like (rod-like), flake-like, polyhedral-like, ring-like, hollow (in the center part, a cavity or a dielectric exists), dendritic crystals, Other irregular shapes are also included. At least a part of the plurality of metal nanoparticles 5 may be aggregated to form a secondary particle.
  • the average primary particle diameter of the metal nanoparticles 5 is 5 to 100 nm, preferably 5 to 80 nm, and more preferably 5 to 40 nm. If the average primary particle diameter of the metal nanoparticles 5 is within the above range, the electric field enhancing effect by localized surface plasmon resonance is excellent.
  • TEM transmission electron microscope
  • AFM atomic force microscope
  • the average primary particle size of the metal nanoparticles 5 may be conveniently measured by a particle size distribution analyzer by a dynamic light scattering method.
  • a particle size distribution analyzer by a dynamic light scattering method.
  • secondary particles aggregates in which primary particles are aggregated
  • a plurality of peaks are generated in the particle size distribution curve, and therefore the peak with the smallest particle diameter is the target particle diameter.
  • the same result as the measurement method using the above SEM can be obtained.
  • a measuring method using a microscopic means such as SEM is useful when analyzing the surface of a substrate for analysis as a product later, and a measuring method by dynamic light scattering method is useful for producing an analytical substrate .
  • the shortest distance between two adjacent metal nanoparticles 5 arranged on the metal film 3 at a distance is preferably 1 to 20 nm, more preferably 1 to 10 nm, and still more preferably 1 to 5 nm. If the shortest distance is within the above range, electric field enhancement occurs by localized surface plasmon resonance between the metal nanoparticles 5, and high sensitivity Raman spectroscopy of the measurement target molecules adsorbed between the metal nanoparticles 5 Analysis is possible. In addition, even if the metal nanoparticles 5 are grounded to the metal film 3, minute gaps between the metal film 3 and the metal nanoparticles 5 are generated in the vicinity of the contact points, so here also by localized surface plasmon resonance. Electric field enhancement occurs to enable highly sensitive Raman spectroscopy.
  • the said shortest distance acquires the microscopic image of the surface sample of the board
  • SEM scanning electron microscope
  • TEM transmission electron microscope
  • AFM atomic force microscope
  • Examples of the method for producing the analysis substrate 10 include the following production method (I).
  • step I-1 a plurality of regions where metal is not deposited remain on the first surface 1a as island-like gaps having a length of 1 ⁇ m or less in the long axis direction, and sheet resistance on the surface of the metal film
  • the metal film 3A is obtained. If the deposition of metal is continued without completion, the non-film formation region G disappears, and the unevenness of the film surface becomes small, and the metal film 3B having a flat surface is formed.
  • an original plate having a two-dimensional lattice structure formed on the surface or a transferred product thereof can be used as the substrate 1.
  • Such an original plate or a transferred product thereof may be one produced by a known production method or a commercially available one.
  • the original plate is obtained by forming a two-dimensional lattice structure on the surface of the original plate.
  • the original plate is the same as the substrate 1 except that the original plate does not have a predetermined two-dimensional lattice structure on the surface.
  • a method of forming a two-dimensional lattice structure on the surface of the original plate for example, dry etching (colloidal lithography) using a single particle film as an etching mask, electron beam lithography, mechanical cutting, laser thermal lithography, Nanoimprint method from a transfer master having a two-dimensional lattice structure on the surface, which is manufactured by the interference exposure method, more specifically, the two-beam interference exposure method, the reduction exposure method, the anodic oxidation method of alumina, and any of them. Etc.
  • a method of forming a two-dimensional lattice structure various methods can be applied, such as a photolithography method combining electron beam drawing and dry etching, a nanoporous alumina anodic oxidation method, or a nanoimprint method using a master obtained therefrom.
  • a dry etching method (colloidal lithography method) using a single particle film as an etching mask is preferable in that a microstructure can be produced with a large area and low cost.
  • the colloidal lithography method can easily produce a plurality of structures with different pitches, and has an advantage that structure optimization and functional verification can be performed quickly.
  • a step of disposing a single particle film on an original plate (a substrate before forming a two-dimensional lattice structure on the surface) (a single particle film disposing step); It can carry out by the manufacturing method including the process (dry etching process) which dry-etches a single particle film and the said original plate.
  • the monoparticulate film and each step will be described in detail later.
  • the method of depositing the metal on the first surface 1a is not particularly limited, and examples thereof include dry methods such as vapor deposition, and wet methods such as electrolytic plating and electroless plating.
  • dry methods include various vacuum sputtering methods, physical vapor deposition methods (PVD) such as vacuum deposition methods, and various chemical vapor deposition methods (CVD).
  • PVD physical vapor deposition methods
  • CVD chemical vapor deposition methods
  • metal film deposition metal deposition
  • a plurality of metal particles adhere to the entire first surface 1a, and the metal particles are joined by growth to form fine particles.
  • Plural island-shaped metal films are formed.
  • adjacent metal films form larger clusters, and the area and thickness of the metal films increase.
  • the region where the metal is not deposited on the first surface 1a becomes narrower.
  • the film formation is completed in a state in which the area where the metal is not deposited remains like an island and the value of the surface sheet resistance of the formed metal film falls within the above range (the metal film becomes a continuous film).
  • the aforementioned metal film 3A is obtained.
  • An area in which the island remains and in which the metal is not deposited is a non-film formation area G. If the deposition of metal is continued without completion, the non-film formation region G disappears and it becomes the metal film 3B.
  • a catalyst When a catalyst is dispersedly disposed on the first surface 1a in advance and a metal film is formed by electroless plating in that state, first, metal adheres to the periphery of the catalyst, and a plurality of fine island-shaped metal films are formed. Be done. As the electroless plating progresses, as in the case of the dry method, the metal films form larger clusters, and the region on which the metal is not deposited on the first surface 1a is narrowed.
  • the above-described metal film 3A is obtained by completing the film formation in a state where the region where metal is not deposited remains in an island shape and the surface sheet resistance value of the formed metal film is in the above range. An area in which the island remains and in which the metal is not deposited is a non-film formation area G. If the deposition of metal is continued without completion, the non-film formation region G disappears and it becomes the metal film 3B.
  • the metal film 3 is preferably a film formed by sputtering.
  • the fact that a plurality of regions where metal is not deposited remains in the form of islands on the first surface 1a is 100,000 times as large as with a high magnification microscope such as atomic force microscope (AFM) or scanning electron microscope (SEM) This can be confirmed by surface observation of the degree.
  • the sheet resistance of the surface of the metal film 3 at the end of the deposition is preferably 3 to 500 ⁇ / ⁇ , and most preferably 3 to 300 ⁇ / ⁇ .
  • the dispersion medium of the metal nanoparticle dispersion liquid may be any one as long as the metal nanoparticles 5 can be dispersed, and examples thereof include water, ethanol, and other organic solvents.
  • the content of the metal nanoparticles 5 in the metal nanoparticle dispersion may be, for example, 0.01 to 10.0 mass% with respect to the total mass of the metal nanoparticle dispersion, and further 0.1 to 1 It may be 0 mass%.
  • the metal nanoparticle dispersion may further contain citric acid, various inorganic salts, and the like as a dispersion stabilizer, as needed, as long as the effects of the invention are not impaired.
  • a coating method of a metal nanoparticle dispersion liquid it can select suitably from well-known coating methods, such as a spray method, a drop cast method, a dip coating method, a spin coat method, an inkjet printing method.
  • the spray method or the inkjet printing method is preferable in that metal nanoparticles can be densely and uniformly arranged on the substrate surface by metal nanoparticle dispersion.
  • step I-1 or after step I-2 when stored for a long time under normal environment (in air), contaminants in the air adhere to the metal structure on the substrate surface, and the effect of the present invention It may decrease. Therefore, storage is preferably performed in a vacuum vessel or an inert gas such as nitrogen or argon. If the effect of the present invention is reduced due to contaminants in the air, the substrate may be subjected to surface treatment such as ultraviolet (UV) / ozone to restore its function, if necessary. Good.
  • UV ultraviolet
  • the “single particle film” is a single layer film in which a plurality of particles are two-dimensionally arranged.
  • the material of the particles constituting the single particle film is not particularly limited, and may be an organic material, an inorganic material, or a composite material of an organic material and an inorganic material.
  • the organic material include thermoplastic resins such as polystyrene and polymethyl methacrylate (PMMA); thermosetting resins such as phenol resin and epoxy resin; and the like.
  • the inorganic material include carbon allotropes, inorganic carbides, inorganic oxides, inorganic nitrides, inorganic borides, inorganic sulfides, inorganic selenides and the like.
  • Examples of the carbon allotrope include diamond, graphite, fullerenes and the like.
  • Examples of inorganic carbides include silicon carbide and boron carbide.
  • Examples of the inorganic oxide include silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, zinc oxide, tin oxide, yttrium aluminum garnet (YAG) and the like.
  • Examples of the inorganic nitride include silicon nitride, aluminum nitride, boron nitride and the like.
  • Examples of inorganic borides include ZrB 2 and CrB 2 .
  • inorganic sulfides include zinc sulfide, calcium sulfide, cadmium sulfide, strontium sulfide and the like.
  • inorganic selenides include zinc selenide and cadmium selenide.
  • the material constituting the particles may be one kind or two or more kinds.
  • the average particle diameter of the particles constituting the single particle film corresponds to the pitch of the periodic uneven structure calculated by the above-mentioned method in accordance with the excitation wavelength used for the spectral analysis. If the average particle diameter of the particles is the above calculated value, propagation surface plasmons are easily induced.
  • the average particle diameter of the particles in a slurry state not constituting the single particle film can be determined by a conventional method from the peak obtained by fitting the particle size distribution determined by the particle dynamic light scattering method to a Gaussian curve It is the diameter.
  • the coefficient of variation (the value obtained by dividing the standard deviation by the average value) of the particle diameter of the particles constituting the single particle film is preferably 20% or less 10% or less is more preferable, and 5% or less is more preferable.
  • the coefficient of variation coefficient of particle diameter that is, small variation of particle diameter
  • misalignment D of the arrangement of particles is 10%. It is possible to obtain a highly accurate single particle film which is as follows.
  • a single particle film in which the misalignment D is 10% or less each particle is two-dimensionally close-packed, the particle spacing is controlled, and the accuracy of the alignment is high. Therefore, if such a single particle film is disposed on the original plate and dry etching is performed, a highly accurate two-dimensional lattice structure can be formed on the surface of the original plate.
  • the present invention is not limited to this, and a single particle film may be composed of particles having a large variation coefficient of particle diameter.
  • a single particle film may be configured using a mixture of a plurality of particle groups having different average particle sizes.
  • the deviation D of the arrangement of particles is defined by the following formula (1).
  • D [%]
  • A is an average particle diameter of particles constituting a single particle film
  • B is an average pitch between particles in the single particle film.
  • indicates the absolute value of the difference between A and B.
  • the average particle size of the particles is as defined above.
  • the pitch between particles is the distance between the apexes of two adjacent particles, and the average pitch is the average of these. If the particles are spherical, the distance between the apexes of two adjacent particles is equal to the distance between the centers of the two adjacent particles.
  • the average pitch B between particles in the single particle film is determined as follows. First, an atomic force microscope image or a scanning electron microscope image is obtained for a square region of 30 to 40 wavelengths of repeating units of a fine structure in a randomly selected region of a single particle film. For example, in the case of a single particle film using particles of 300 nm in particle diameter, an image of a region of 9 ⁇ m ⁇ 9 ⁇ m to 12 ⁇ m ⁇ 12 ⁇ m is obtained. Then, this image is waveform separated by two-dimensional Fourier transform to obtain an FFT image (fast Fourier transform image). Next, the distance from the zero-order peak to the first-order peak in the profile of the FFT image is determined.
  • FFT image fast Fourier transform image
  • the inverse of the calculated distance is the average pitch B 1 in this region.
  • Such processing is similarly performed on randomly selected areas of 25 areas or more having the same area in total, and average pitches B 1 to B 25 in each area are determined.
  • the average value of the average pitches B 1 to B 25 in the region of 25 or more places thus obtained is the average pitch B in the equation (1).
  • the respective regions are preferably selected to be separated by at least 1 mm, and more preferably selected to be separated by 5 mm to 1 cm. At this time, it is also possible to evaluate, for each image, the variation in pitch among particles in each image from the half width of the primary peak in the profile of the FFT image.
  • the single particle film disposing step is preferably performed by the Langmuir-Blodgett method (LB method).
  • LB method Langmuir-Blodgett method
  • This method combines the accuracy of single-layering, the simplicity of operation, the response to an increase in area, the reproducibility, etc., for example, the liquid thin film described in Nature, Vol. 361, 7 January, 26 (1993), etc. It is extremely superior to the so-called particle adsorption method described in U.S. Pat.
  • a water tank (trough) containing water as a liquid (hereinafter sometimes referred to as a lower layer liquid) for developing particles on the liquid surface is prepared, and the liquid Step of dropping a dispersion in which particles are dispersed in an organic solvent having a smaller specific gravity than water on a surface (dropping step) and step of forming a single particle film composed of particles by volatilizing the organic solvent (single particle A film formation process can be implemented by the method including the process (transfer process) which transfers the formed single particle film to a negative
  • particles having a hydrophobic surface are used as the particles so that the particles do not dip below the surface of the hydrophilic lower layer liquid.
  • a hydrophobic solvent is selected so that when the dispersion is dropped onto the liquid surface of the lower layer liquid, the dispersion will expand to the air-liquid interface of the air and the lower layer liquid without mixing with the lower layer liquid. Be done.
  • the particles having a hydrophobic surface and the organic solvent having a hydrophobic surface are selected, and the lower layer liquid is hydrophilic, but the particles having a hydrophilic surface and an organic solvent are used.
  • a hydrophilic solvent may be selected, and a hydrophobic liquid may be used as the lower layer liquid.
  • the organic solvent used for the dispersion is a hydrophobic one having a smaller specific gravity than water. It is also important that the organic solvent have high volatility.
  • organic solvents having a specific gravity smaller than water and being hydrophobic and having high volatility include chloroform, methanol (used as a material for mixing), ethanol (used as a material for mixing), isopropanol (used as a material for mixing), acetone (Used as a material for mixing) Volatile organic solvents comprising one or more kinds of methyl ethyl ketone, diethyl ketone, toluene, hexane, cyclohexane, ethyl acetate, butyl acetate and the like.
  • particles having an organic material such as polystyrene and having an originally hydrophobic surface may be used as the particles having a hydrophobic surface, and the particles having a hydrophilic surface are treated with a hydrophobicizing agent.
  • a hydrophobicizing agent for example, surfactants, metal alkoxides and the like can be used.
  • the method of using a surfactant as a hydrophobizing agent is effective for hydrophobization of a wide range of materials, and is suitable when the particles are made of an inorganic oxide or the like.
  • the method of using a metal alkoxide as a hydrophobizing agent is effective in hydrophobizing inorganic oxide particles such as aluminum oxide, silicon oxide and titanium oxide.
  • inorganic oxide particles such as aluminum oxide, silicon oxide and titanium oxide.
  • the present invention can be applied to particles having a hydroxyl group on the surface.
  • cationic surfactants such as hexadecyltrimethylammonium bromide and decyltrimethylammonium bromide
  • anionic surfactants such as sodium dodecyl sulfate and sodium 4-octylbenzene sulfonate
  • alkanethiols, disulfide compounds, tetradecanoic acid, octadecanoic acid and the like can be used.
  • an alkoxysilane is mentioned, for example.
  • the alkoxysilane monomethyltrimethoxysilane, monomethyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2 -(3,4-Epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane Silane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-meth
  • the hydrophobization treatment using a surfactant may be carried out by dispersing particles in a liquid such as an organic solvent or water, and may be carried out on particles in a dry state.
  • a liquid such as an organic solvent or water
  • particles to be hydrophobized may be added and dispersed in the above-mentioned volatile organic solvent, and then the surfactant may be mixed and dispersion may be continued.
  • the dispersion after such hydrophobization treatment can be used as it is as a dispersion for dropping onto the liquid surface of the lower layer liquid in the dropping step.
  • the particles to be hydrophobized are in the form of an aqueous dispersion
  • a surfactant is added to the aqueous dispersion to perform hydrophobization on the particle surface in the aqueous phase, and then an organic solvent is added to hydrophobize.
  • the method of oil phase extraction of the finished particles is also effective.
  • the dispersion (dispersion in which the particles are dispersed in the organic solvent) thus obtained can be used as it is as a dispersion to be dropped onto the liquid surface of the lower layer liquid in the dropping step.
  • a dispersion having high particle dispersibility By using a dispersion having high particle dispersibility, it is possible to suppress aggregation of particles in the form of clusters, and it becomes easier to obtain a single particle film in which each particle is densely packed in two dimensions.
  • chloroform when chloroform is selected as the organic solvent, it is preferable to use decyltrimethylammonium bromide as the surfactant.
  • a combination of ethanol and sodium dodecyl sulfate, a combination of methanol and sodium 4-octylbenzene sulfonate, a combination of methyl ethyl ketone and octadecanoic acid, and the like can be preferably exemplified.
  • the ratio of the particles to be hydrophobized to the surfactant is preferably such that the mass of the surfactant is 1/3 to 1/15 times the mass of the particles to be hydrophobized. In the case of such hydrophobization treatment, it is also effective to stir the dispersion during treatment or to irradiate the dispersion with ultrasonic waves in terms of improvement of the particle dispersibility.
  • the alkoxy group bonded to the metal atom in the metal alkoxide is hydrolyzed to form a hydroxyl group.
  • the alkoxysilyl group is hydrolyzed to form a silanol group (Si-OH).
  • Hydrophobization is performed by dehydrating condensation of the generated hydroxyl groups with hydroxyl groups on the particle surface. Therefore, it is preferable to carry out the hydrophobization treatment using a metal alkoxide in water.
  • the hydrophobization treatment is carried out in water as described above, it is preferable to stabilize the dispersion state of the particles before hydrophobization by using, for example, a dispersing agent such as a surfactant, depending on the kind of the dispersing agent. Since the hydrophobization effect of the metal alkoxide may be reduced, the combination of the dispersant and the metal alkoxide is appropriately selected.
  • a dispersing agent such as a surfactant
  • the particles are dispersed in water, and this is mixed with a metal alkoxide-containing aqueous solution (an aqueous solution containing a hydrolyzate of metal alkoxide),
  • a metal alkoxide-containing aqueous solution an aqueous solution containing a hydrolyzate of metal alkoxide
  • the reaction is carried out for a predetermined time, preferably 6 to 12 hours, with appropriate stirring in the range of ° C.
  • the reaction proceeds moderately, and a dispersion liquid of sufficiently hydrophobized particles can be obtained.
  • the silanol groups react with each other to combine the particles with each other, the particle dispersibility of the dispersion decreases, and in the obtained single particle film, the particles partially aggregate in a cluster 2 It is easy to become more than a layer.
  • the reaction is insufficient, the hydrophobicization of the particle surface also becomes insufficient, and in the operation of developing the particles to be described later on the water surface, problems occur that the particles settle in water, or the strength of the obtained single particle film decreases. It is not preferable because wrinkle-like defects occur.
  • the alkoxysilanes other than amine based hydrolyze under acidic or alkaline conditions it is necessary to adjust the pH of the dispersion to be acidic or alkaline during the reaction.
  • There is no limitation on the method of adjusting the pH but according to the method of adding an aqueous acetic acid solution having a concentration of 0.1 to 2.0% by mass, in addition to the promotion of hydrolysis, the effect of stabilizing the silanol group is also obtained.
  • the ratio of the particles to be hydrophobized to the metal alkoxide is preferably such that the mass of the metal alkoxide is 1/3 to 1/100 times the mass of the particles to be hydrophobized.
  • the volume of the organic solvent to be added is preferably 0.3 to 3 times the volume of the dispersion before addition of the organic solvent.
  • the dispersion (dispersion in which the particles are dispersed in the organic solvent) thus obtained can be used as it is as a dispersion to be dropped onto the liquid surface of the lower layer liquid in the dropping step.
  • the concentration of particles in the dispersion to be dropped to the lower layer solution is preferably 1 to 10% by mass.
  • the dropping speed of the dispersion is preferably 0.001 to 0.01 mL / sec.
  • the dispersion before dropping onto the liquid surface is precision filtered with a membrane filter or the like, and aggregated particles (secondary particles consisting of a plurality of primary particles) present in the dispersion Is preferred to be removed.
  • aggregated particles secondary particles consisting of a plurality of primary particles
  • a surface pressure sensor that measures the surface pressure of the single particle film in the transition step described in detail later; Even if an LB trough apparatus provided with a movable barrier that compresses a single particle film in the liquid surface direction is used, such a defect is not detected as a difference in surface pressure, and a high accuracy single particle film can be obtained. It becomes difficult.
  • Single particle film formation process When the dispersion liquid is dropped onto the liquid surface of the lower layer liquid in the dropping step, the solvent as the dispersion medium is volatilized, and the particles are spread in a single layer on the liquid surface of the lower liquid layer, and the particles are two-dimensionally dense Can be formed.
  • this single particle film is due to the self-organization of the particles.
  • the principle is that when particles are concentrated, surface tension acts due to the dispersion medium present between the particles, and as a result, the particles are not separated from each other, but are concentrated on the liquid surface of the lower layer liquid Automatically forms a single layer structure.
  • the formation of a single layer structure by such surface tension can be said to be mutual adsorption of particles due to the lateral capillary force.
  • surface tension acts to minimize the total length of the waterline of the particle group, and the three particles are based on an equilateral triangle. Stabilize in place.
  • the lower layer liquid it is preferable to use water as described above, and when water is used, relatively large surface free energy acts to form a dense single layer structure of particles once generated on the liquid surface. It becomes stable and easy to sustain.
  • the single particle film forming step is preferably performed under ultrasonic irradiation conditions.
  • the single particle film forming step is performed while irradiating ultrasonic waves from the lower layer solution to the water surface, mutual adsorption of particles is promoted, and a single particle film in which each particle is densely packed in two dimensions can be obtained.
  • the output of the ultrasonic wave is preferably 1 to 1200 W, more preferably 50 to 600 W.
  • the frequency of ultrasonic waves is not particularly limited, but for example, 28 kHz to 5 MHz is preferable, and 700 kHz to 2 MHz is more preferable.
  • the frequency is too high, energy absorption of water molecules starts, and a phenomenon that water vapor or water droplets rise from the water surface occurs, which is not preferable for the LB method. If the frequency is too low, the cavitation radius in the lower layer solution will be large, and bubbles will be generated in the water and will rise toward the water surface. When such bubbles accumulate under the monoparticle film, the flatness of the water surface is lost, which is disadvantageous for the LB method.
  • ultrasonic waves are applied, standing waves are generated on the water surface. If the output is too high at any frequency, or if the wave height of the water surface is too high due to the tuning conditions of the ultrasonic transducer and the transmitter, the single particle film is broken by the water wave, so care must be taken.
  • the frequency of ultrasonic waves is set appropriately in consideration of the above, it is possible to effectively promote the concentration of particles without destroying the monoparticle film being formed.
  • the particle size is small, for example, 100 nm or less, the natural frequency becomes very high, and it becomes difficult to give ultrasonic vibration as calculated. In such a case, it is possible to reduce the necessary frequency to a realistic range by performing calculations assuming that the natural vibration corresponding to the mass from the particle dimer to about 20 mer is given. .
  • the irradiation time of the ultrasonic waves may be sufficient to complete the rearrangement of the particles, and the required time changes depending on the particle diameter, the frequency of the ultrasonic waves, the water temperature, and the like. However, under normal preparation conditions, it is preferably performed for 10 seconds to 60 minutes, more preferably for 3 minutes to 30 minutes.
  • the advantages obtained by the ultrasonic irradiation include the effect of destroying the soft agglomerates of particles that are easily generated during preparation of the nanoparticle dispersion, point defects, line defects, or crystals that are easily generated during preparation of the nanoparticle dispersion, in addition to high-density packing of particles. There is an effect of repairing the metastasis etc. to some extent.
  • the single particle film formed on the liquid surface in the single particle film forming step is transferred onto the original plate in a single layer state.
  • the original plate is the same as the substrate 1 except that the two-dimensional lattice structure is not formed on the surface.
  • the hydrophobic original plate is lowered from above while being kept substantially parallel to the single particle membrane to form a single particle membrane.
  • an original plate is dipped in a substantially vertical direction in a lower layer solution in a water tank in advance, and the dropping step and the single particle film forming step described above are performed in this state to form a single particle film. Then, after the single particle film forming step, the single particle film can be transferred onto the original plate by pulling the original plate upward. Since the single particle film is already formed in a single layer state on the liquid surface of the lower layer liquid in the single particle film forming step, the temperature condition of the transfer step (the temperature of the lower layer liquid) and the pulling speed of the original plate are somewhat Even if it fluctuates, there is no fear that the single particle film collapses and becomes multilayered in the transfer step.
  • the temperature of the lower layer liquid is usually about 3 to 30 ° C., depending on the environmental temperature which fluctuates depending on the season and the weather.
  • an LB trough apparatus including a surface pressure sensor based on a Wilhelmy plate or the like for measuring the surface pressure of a single particle film as a water tank and a movable barrier for compressing the single particle film in the direction along the liquid surface.
  • the single particle film can be compressed to a preferable diffusion pressure (density) while measuring the surface pressure of the single particle film, and can be moved at a constant speed toward the substrate. .
  • the preferred diffusion pressure is 5 to 80 mNm -1 , more preferably 3 to 40 mNm -1 . With such a diffusion pressure, it is easy to obtain a single particle film in which each particle is densely packed two-dimensionally.
  • the speed of pulling up the original plate is preferably 0.5 to 20 mm / min.
  • the LB trough apparatus can be obtained as a commercial product.
  • the metal alkoxide exemplified as the hydrophobizing agent a general organic binder, an inorganic binder and the like can be used.
  • the amount of binder used is preferably 0.001 to 0.02 mass times the mass of the single particle film. In such a range, the particles can be sufficiently fixed without causing a problem that the binder is too much and the binder is clogged between particles, which adversely affects the accuracy of the single particle film.
  • the binder solution may be removed by using a spin coater or tilting the original plate after the binder solution has penetrated. After the binder solution has penetrated, heat treatment may be appropriately performed according to the type of the binder. When a metal alkoxide is used as a binder, heat treatment is preferably performed at 40 to 80 ° C. for 3 to 60 minutes.
  • the original plate on which the single particle film is formed may be heated to fuse the particles constituting the single particle film to the original plate.
  • the heating temperature may be determined according to the material of the particles and the material of the original plate. In the case of particles having a particle diameter of 1 ⁇ m or less, the interfacial reaction is initiated at a temperature lower than the melting point inherent to the material constituting the particles, so sintering is completed at a relatively low temperature side.
  • the heating temperature is too high, the fused area of the particles becomes large, and as a result, the shape of the single particle film may be changed, which may affect the accuracy.
  • the heating is performed in air, depending on the material, the original plate and the particles may be oxidized.
  • a thermally oxidized layer is formed on the surface of this substrate with a thickness of about 200 nm. Therefore, in the dry etching process described later, it is necessary to set the etching conditions in consideration of the possibility of such oxidation.
  • the original plate is dry etched using the single particle film as an etching mask under the condition that both the particles and the original plate are substantially etched.
  • each particle constituting the single particle film is etched, the particle diameter of each particle gradually decreases, and a gap is also formed in a portion where the particles are in contact with each other before dry etching.
  • the particles are formed, and the particles are not in contact with each other.
  • the etching gas passes through the gaps between the particles to reach the surface of the original plate, and the surface of the original plate located below the gaps is etched to form a recess.
  • the part covered with particles remains unetched, and this part becomes the convex 3c. Thereby, the substrate 1 is obtained.
  • the particles may be dry etched under conditions that the original plate is not substantially etched.
  • the thickness of the convex portion 3c (occupied volume in surface layer: filling factor), convex portion 3c Height (the depth of the recess) etc. can be adjusted.
  • the etching gas can be appropriately selected from known etching gases according to the material of the particles, the substrate, etc., so that both the particles and the original plate can be etched.
  • the original plate is glass and the particles are silica (SiO 2 )
  • the original plate is quartz and the particles are silica
  • Ar or CF 4 can be used.
  • Cl 2 , BCl 3 , SiCl 4 , HBr, HI, HCl, etc. can be used.
  • the etching gas may be used alone or in combination of two or more. Adjustment of etching conditions is facilitated by the mixing ratio of two or more etching gases.
  • the etching gas may be diluted with a gas other than the etching gas.
  • the dry etching is preferably performed by anisotropic etching in which the etching rate in the vertical direction is larger than in the horizontal direction of the original plate.
  • anisotropic etching such as a reactive ion etching apparatus, an ion beam etching apparatus, etc., and generate a bias electric field of about 20 W at the minimum, it is possible to generate plasma
  • There are no particular limitations on specifications such as the method, the structure of the electrode, the structure of the chamber, and the frequency of the high frequency power source.
  • the etching selectivity in dry etching is not particularly limited, and each condition of etching (material of particles constituting single particle film, material of original plate, type of etching gas, The bias power, antenna power, gas flow rate, pressure, etching time, etc. can be adjusted.
  • the dry etching of the original plate may be ended when the particles constituting the single particle film disappear, or may be ended before the particles disappear.
  • the particles remaining on the formed substrate 1 are removed after the dry etching of the original plate.
  • the method for removing particles include a chemical removal method using an etchant which is etchable to particles and etch resistant to the substrate 1, and a physical removal method using a brush roll cleaner or the like.
  • the original plate is obtained as described above.
  • the transferred product of the original plate is obtained by transferring the two-dimensional lattice structure of the original plate surface to another original plate one or more times.
  • a transfer product having a two-dimensional lattice structure in which the two-dimensional lattice structure of the original plate surface is inverted is obtained.
  • a transfer product having a two-dimensional lattice structure similar in shape to the two-dimensional lattice structure of the original plate surface is obtained.
  • the two-dimensional lattice structure of the original plate surface is transferred to a mold (a mold or a stamper) (first transfer), and then the two-dimensional lattice structure of the mold is transferred (second transfer).
  • a transfer product having a two-dimensional lattice structure of the same shape as the two-dimensional lattice structure is obtained.
  • an electroforming method as disclosed in JP 2009-158478 A is preferable.
  • Examples of a method for transferring a two-dimensional lattice structure of a mold include a nanoimprinting method, a heat pressing method, an injection molding method, a UV embossing method, and the like as disclosed in JP-A-2009-158478. Above all, the nanoimprint method is suitable for the transfer of a fine two-dimensional lattice structure.
  • the analysis substrate 10 is also excellent in productivity.
  • metal can be deposited on the substrate 1B, and further, the metal nanoparticle dispersion can be coated and dried.
  • the analytical substrate 10 is useful for optical analysis utilizing electric field enhancement by surface plasmon resonance. As such an optical analysis method, the same as described above can be mentioned.
  • the analysis substrate 10 is useful for optical analysis utilizing an electric field enhancement effect by surface plasmon resonance.
  • optical analysis include Raman spectroscopy, infrared spectroscopy, and fluorescence analysis.
  • Raman spectroscopy is preferable.
  • the Raman spectroscopy is an analysis means for observing the Raman scattering shifted by the vibrational energy of the molecule with respect to the incident light when the sample is irradiated with light, and analyzing the structure at the molecular level.
  • the obtained Raman spectrum is a vibration spectrum based on the vibration of the molecule, the vertical axis is the scattering intensity (Intensity), and the horizontal axis is the Raman shift (cm ⁇ 1 ) Is represented by
  • the vibration mode of the same functional group is detected in the same wave number in the Raman spectroscopy and the infrared spectroscopy, but unlike the infrared spectroscopy, the Raman spectroscopy can measure the aqueous sample, so the living body It has the advantage of not requiring pretreatment of the sample in analysis of the sample, food sample, etc.
  • Raman spectroscopy without surface electric field enhancement has the disadvantage that the intensity of the Raman scattered light is very low.
  • Surface enhanced Raman spectroscopy is Raman spectroscopy using SERS.
  • the Raman scattering (Stokes scattering and anti-Stokes scattering) intensity of the molecules adsorbed on the surface of the analysis substrate 10 can be significantly enhanced by the SERS effect, which enables high sensitivity spectral analysis. .
  • SERS Raman scattering
  • even in the case of a dilute trace sample it is possible to detect a spectrum unique to a substance, which is useful for environmental measurement, measurement of a trace biomarker, detection of a biological or chemical weapon, and the like.
  • FIG. 4 shows an example in which the shape of the non-film formation region G in a top view is a band shape, but the shape of the non-film formation region G in a top view is not limited thereto. For example, it may have a circular shape, a rectangular shape, a tree shape, or an irregular shape.
  • the shape, size, and distribution of each of the plurality of non-film formation regions G are random (not constant), the shape and size of each of the plurality of non-film formation regions G may be constant.
  • the plurality of non-film formation regions G may be regularly arranged.
  • FIG. 5 shows an example in which the metal surface 3 a surrounding the non-film formation region G is an inclined surface, the metal surface 3 a may be a non-inclined surface.
  • the metal surface 3a may be a smooth surface or an uneven surface.
  • the metal film is a metal film formed by a method of depositing metal on the first surface of the substrate (sputtering method, vacuum evaporation method, etc.)
  • the metal surface surrounding the non-film formation region G is locally inclined In many cases, it is an irregular surface.
  • the gap in the minor axis direction of the non-film formation region G is called a nanogap.
  • Measurement gaps in the nanogap first two arguments diagonal L D in the SEM image obtained as described above, all the non-deposition region G moiety regard measuring the gap width in the minor axis direction of the diagonal lines Do.
  • the length measurement is performed at the intersection where the diagonal intersects each non-film formation region G. Specifically, a point P which is a half of the intersection distance formed by the diagonal with the non-film formation region G is defined.
  • the thickness of the metal film 3 was measured by the above-mentioned method. That is, a very thin scratch (scratch) is made with a sharp knife tip to the metal film 3 deposited on the substrate, and the area including the scratch is measured by a stylus-type step meter (fine shape measuring machine ET4000A
  • the average thickness of the metal film 3 was measured by a method of measuring the average height difference between the bottom surface of the flaw (where the substrate is exposed) and the surface of the metal film 3 by the Kosaka Research Institute, Ltd. .
  • a stylus type step system is used, but an atomic force microscope (AFM) image is obtained to similarly average the difference in height between the exposed portion of the substrate and the surface of the metal film 3 The same result can be obtained even if it is determined.
  • AFM atomic force microscope
  • the above-mentioned hydrophobized particle slurry was dropped onto the water surface of the lower layer water of pH 7.2 at 21 ° C. to form a particle monolayer film on the water surface. Furthermore, while compressing the particle monolayer film with the barrier, the clean flat quartz substrate previously immersed in water is gradually pulled up at 5 mm / min, and the particle monolayer film on the water surface is transferred onto the quartz substrate.
  • the Au thin film was pressured on the periodic uneven structure at a pressure of 6 to 8 Pa, a current value of 15 mA, and a deposition rate of 11.6 nm / min. The film was formed to a thickness of 8 nm.
  • the step of spray coating an Au nanoparticle dispersion (average primary particle diameter: 20.7 nm) on an Au thin film and drying was repeated three times to disperse and arrange Au nanoparticles on the substrate.
  • FIG. 6 shows an SEM image of the obtained analysis substrate.
  • the above-mentioned hydrophobized particle slurry was dropped onto the water surface of the lower layer water of pH 7.2 at 21 ° C. to form a particle monolayer film on the water surface. Furthermore, while compressing the particle monolayer film with the barrier, the clean flat quartz substrate previously immersed in water is gradually pulled up at 5 mm / min, and the particle monolayer film on the water surface is transferred onto the quartz substrate.
  • an Au thin film was pressured on the periodic uneven structure at a pressure of 6 to 8 Pa, a current value of 15 mA, and a deposition rate of 11.6 nm / min. The film was formed to a thickness of 0 nm.
  • the step of spray coating an Au nanoparticle dispersion (average primary particle diameter: 20.7 nm) on an Au thin film and drying was repeated three times to disperse and arrange Au nanoparticles on the substrate.
  • FIG. 7 shows an SEM image of the obtained analysis substrate.
  • the clean flat quartz substrate previously immersed in water is gradually pulled up at 5 mm / min, and the particle monolayer film on the water surface is transferred onto the quartz substrate.
  • an Au thin film is formed at a pressure of 6 to 8 Pa, a current value of 15 mA, and a deposition rate of 11.6 nm / min.
  • the film was formed to a thickness of 2 nm.
  • the Raman scattering intensity was measured using the analysis substrates of Examples 1 to 2 and Comparative Examples 1 to 3. The results are shown in Table 1.
  • the analysis substrates of Comparative Example 1 and Comparative Example 2 could not detect Raman scattering.
  • the Raman scattering could be detected in the substrate for analysis of Comparative Example 3, its intensity was lower than the intensities of all the examples.
  • Raman scattering at a sample concentration of 100 ⁇ M was obtained at high intensity, and Raman scattering could be detected even at a sample concentration as low as 1 nM.

Landscapes

  • Chemical & Material Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Immunology (AREA)
  • General Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Analytical Chemistry (AREA)
  • Pathology (AREA)
  • Nanotechnology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Composite Materials (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

L'invention concerne un substrat d'analyse (10) qui comprend : un substrat (1) ayant au moins une première surface (1a) qui comprend un diélectrique ou un conducteur et ayant une structure de réseau bidimensionnelle qui a une pluralité de sections en creux ou de sections en saillie disposées périodiquement en deux dimensions sur la première surface (1a) ; une membrane métallique (3) disposée sur la première surface (1a) du substrat (1) et ayant une résistance de couche en surface à 25 °C inférieure ou égale à 5 000 Ω/□ ; et une pluralité de nanoparticules métalliques (5) disposées de manière dispersée sur la membrane métallique (3) et ayant un diamètre de particule élémentaire moyen de 5 à 100 nm.
PCT/JP2019/002253 2018-01-25 2019-01-24 Substrat d'analyse WO2019146692A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-010683 2018-01-25
JP2018010683A JP6954152B2 (ja) 2018-01-25 2018-01-25 分析用基板

Publications (1)

Publication Number Publication Date
WO2019146692A1 true WO2019146692A1 (fr) 2019-08-01

Family

ID=67395540

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/002253 WO2019146692A1 (fr) 2018-01-25 2019-01-24 Substrat d'analyse

Country Status (2)

Country Link
JP (1) JP6954152B2 (fr)
WO (1) WO2019146692A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020054780A1 (fr) * 2018-09-12 2020-03-19 王子ホールディングス株式会社 Substrat d'analyse
RU2766343C1 (ru) * 2020-12-16 2022-03-15 Федеральное государственное унитарное предприятие "Государственный научно-исследовательский институт органической химии и технологии" (ФГУП "ГосНИИОХТ") Способ получения гкр-чипа для иммунохимического анализа

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111337445B (zh) * 2019-12-02 2021-05-07 厦门大学 一种基于角度扫描增强红外光谱吸收的介质超表面
WO2021141709A1 (fr) * 2020-01-09 2021-07-15 Applied Materials, Inc. Procédé d'amélioration de contraste lors de l'imagerie de structures à rapport de forme élevé en microscopie électronique
WO2023210336A1 (fr) * 2022-04-27 2023-11-02 キヤノン株式会社 Substrat, procédé d'analyse, dispositif et procédé de fabrication

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010088726A1 (fr) * 2009-02-04 2010-08-12 University Of South Australia Fabrication de nanoparticules sur des surfaces solides
US20110267610A1 (en) * 2010-04-30 2011-11-03 Min Hu Compact sensor system
US20120170033A1 (en) * 2010-12-31 2012-07-05 Hon Hai Precision Industry Co., Ltd. Method for detecting single molecule
JP2012132875A (ja) * 2010-12-24 2012-07-12 Seiko Epson Corp センサーチップ、センサーチップの製造方法、検出装置
WO2014025035A1 (fr) * 2012-08-10 2014-02-13 浜松ホトニクス株式会社 Elément à diffusion raman exaltée par effet de surface
JP2014163868A (ja) * 2013-02-27 2014-09-08 Seiko Epson Corp 光学素子、分析装置、分析方法、および電子機器
JP2015055482A (ja) * 2013-09-10 2015-03-23 セイコーエプソン株式会社 分析装置、分析方法、これらに用いる光学素子及び電子機器
JP2015163845A (ja) * 2014-02-28 2015-09-10 国立研究開発法人物質・材料研究機構 表面増強ラマンスペクトル用基板

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012516156A (ja) * 2009-01-28 2012-07-19 スマートセルズ・インコーポレイテツド ポリヌクレオチドアプタマー系架橋物質体およびその使用

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010088726A1 (fr) * 2009-02-04 2010-08-12 University Of South Australia Fabrication de nanoparticules sur des surfaces solides
US20110267610A1 (en) * 2010-04-30 2011-11-03 Min Hu Compact sensor system
JP2012132875A (ja) * 2010-12-24 2012-07-12 Seiko Epson Corp センサーチップ、センサーチップの製造方法、検出装置
US20120170033A1 (en) * 2010-12-31 2012-07-05 Hon Hai Precision Industry Co., Ltd. Method for detecting single molecule
WO2014025035A1 (fr) * 2012-08-10 2014-02-13 浜松ホトニクス株式会社 Elément à diffusion raman exaltée par effet de surface
JP2014163868A (ja) * 2013-02-27 2014-09-08 Seiko Epson Corp 光学素子、分析装置、分析方法、および電子機器
JP2015055482A (ja) * 2013-09-10 2015-03-23 セイコーエプソン株式会社 分析装置、分析方法、これらに用いる光学素子及び電子機器
JP2015163845A (ja) * 2014-02-28 2015-09-10 国立研究開発法人物質・材料研究機構 表面増強ラマンスペクトル用基板

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020054780A1 (fr) * 2018-09-12 2020-03-19 王子ホールディングス株式会社 Substrat d'analyse
RU2766343C1 (ru) * 2020-12-16 2022-03-15 Федеральное государственное унитарное предприятие "Государственный научно-исследовательский институт органической химии и технологии" (ФГУП "ГосНИИОХТ") Способ получения гкр-чипа для иммунохимического анализа

Also Published As

Publication number Publication date
JP2019128282A (ja) 2019-08-01
JP6954152B2 (ja) 2021-10-27

Similar Documents

Publication Publication Date Title
WO2019146692A1 (fr) Substrat d'analyse
Pisco et al. Nanosphere lithography for optical fiber tip nanoprobes
Wei et al. Hot spots in different metal nanostructures for plasmon-enhanced Raman spectroscopy
Wang et al. Highly effective and reproducible surface-enhanced Raman scattering substrates based on Ag pyramidal arrays
US8810788B2 (en) Broad band structures for surface enhanced raman spectroscopy
US10520442B2 (en) Nanogap structure having ultrasmall void between metal cores and molecular sensing apparatus and method using the same, and method for preparing the nanogap structure by selective etching
Zhang et al. Advances in contemporary nanosphere lithographic techniques
Zhao et al. Graphene-based hybrid films for plasmonic sensing
Liu et al. A high-performance and low cost SERS substrate of plasmonic nanopillars on plastic film fabricated by nanoimprint lithography with AAO template
JP5162673B2 (ja) 光学的特性を用いたセンサ応用のための基板製造方法およびそれによる基板
Zuo et al. Multiple plasmon couplings in 3D hybrid Au-nanoparticles-decorated Ag nanocone arrays boosting highly sensitive surface enhanced Raman scattering
JP4849375B2 (ja) 微粒子配列体薄膜及びその製造方法、並びに、微粒子配列体薄膜製造装置
WO2019146700A1 (fr) Substrat d'analyse et son procédé de production
Liu et al. Real-time Raman detection by the cavity mode enhanced Raman scattering
Bechelany et al. Extended domains of organized nanorings of silver grains as surface-enhanced Raman scattering sensors for molecular detection
US20170261434A1 (en) Sers substrate
WO2020054780A1 (fr) Substrat d'analyse
Park et al. Fabrication of highly uniform three-dimensional SERS substrates by control of wettability
Liu et al. Deep-elliptical-silver-nanowell arrays (d-EAgNWAs) fabricated by stretchable imprinting combining colloidal lithography: A highly sensitive plasmonic sensing platform
JP6780607B2 (ja) 分析用基板およびその製造方法
Rastogi et al. Nanoplasmonic Arrays with High Spatial Resolutions, Quality, and Throughput for Quantitative Detection of Molecular Analytes
Zhao et al. Rapid templated fabrication of large-scale, high-density metallic nanocone arrays and SERS applications
Liu et al. Bottom-up growth of Ag/a-Si@ Ag arrays on silicon as a surface-enhanced Raman scattering substrate with high sensitivity and large-area uniformity
Kondo et al. High-Throughput Fabrication of Substrates for Surface-Enhanced Raman Scattering Measurement Based on Nanoimprinting Process Using Anodic Porous Alumina
Tang et al. Metallic nanocrystals near ultrasmooth metallic films for surface-enhanced Raman scattering application

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19744339

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19744339

Country of ref document: EP

Kind code of ref document: A1