WO2006093055A1

WO2006093055A1 - Chip for optical analysis, method for manufacturing the same, optical analyzer, and optical analyzing method

Info

Publication number: WO2006093055A1
Application number: PCT/JP2006/303489
Authority: WO
Inventors: Hideki Miyazaki; Yoichi Kurokawa
Original assignee: National Institute For Materials Science
Priority date: 2005-03-03
Filing date: 2006-02-24
Publication date: 2006-09-08
Also published as: JP4117665B2; JPWO2006093055A1

Abstract

There is provided a chip for analysis realizing high sensitivity analysis based on an optical signal represented by Raman scattering light by utilizing surface plasmon resonance. The chip for optical analysis comprises a negative dielectric, and a positive dielectric in solid state arranged in at least one groove formed in the surface of the negative dielectric. An analysis object substance is arranged on the surface of the chip and irradiated with light and then light radiated from the analysis object substance is measured. Analysis by Raman scattering light, for example, can be carried out with high sensitivity by resonance of surface wave in TM0 mode.

Description

Specification

Optical analysis chip and manufacturing method thereof, optical analysis device, and optical analysis method

Technical field

The present invention relates to a chip, an analysis device, and an analysis method for analyzing a substance component, concentration, state, and the like with high sensitivity based on a light emission signal with respect to light irradiation such as Raman scattered light, fluorescence, and harmonic light. It is about.

Background art

[0002] In order to analyze a component, concentration, and state of a substance, a method of measuring the intensity and spectrum of light of another wavelength emitted from the object by irradiating the object with light has been developed. Specifically, Raman scattering light, fluorescence, harmonic light, etc. are known as such a light emission process.

[0003] In particular, Raman scattered light shows a spectrum that reflects the molecular structure in detail, so it is useful for understanding the substance, the state of the molecule, and the environment in which the molecule is placed. In addition, harmonic light, especially second harmonic light, provides information such as molecular orientation at the interface. However, in contrast to their usefulness, these optical signals are very weak.

[0004] One method for capturing such a weak signal with high sensitivity is to improve the performance of the light source or detector by irradiating strong light or capturing the weak signal. However, there is another fundamentally different method. The luminescent properties of a substance are usually considered to be intrinsic to that substance, but this is not the case. The light emission process of a material is determined by factors such as the density of states of the radiation field in the space where the material is placed, in addition to the intrinsic properties of the material. The state density of the radiation field can be artificially modified. Even if the environment surrounding the substance is properly arranged, even the substance that is usually considered to be weak and difficult to detect can enhance the luminescence itself and detect it with high sensitivity. During normal analysis, the target substance is suspended in the solution or attached to the surface of the slide glass. In such a case, the density of states in the surrounding environment of the substance is almost the same as in free space. Therefore, when analyzing the luminescence of these substances, only the intrinsic properties of the substance are reflected, and the luminescence from a substance with weak luminescence is only detected as a weak signal. Not. Usually, we tend to think that the light emission characteristics of a force substance are determined only by the inherent properties of the substance, because the usual analytical method is based on the premise that the substance is placed in a solution or on the surface of a simple glass slide. .

[0005] However, when the same substance is placed in a resonator for the light and the same measurement is performed, strong luminescence can be detected even with the same light source and detector. In other words, a resonator is a structure made so that the density of states of the radiation field is high for a specific wavelength (wavelength when propagating in vacuum, hereinafter referred to as vacuum wavelength) λ 0. Can do. The strength of the effect of increasing the density of states of the radiation field in the resonator is expressed by the parcel coefficient. The parcel coefficient is proportional to the Q value and inversely proportional to the volume of the resonator. The Q value is an index representing energy stored in the resonator or electric field enhancement. In order to obtain a large parcel coefficient, it is important to confine a large electromagnetic field in a small volume. Note that the phenomenon discussed here is not limited to a narrow-sense phenomenon called the parcel effect.

[0006] As an example of such a phenomenon in which light emission enhancement actually occurs, there is a surface enhanced Raman scattering phenomenon. As a specific method, when molecules to be analyzed are adsorbed on the surface of silver or gold with moderate irregularities on the surface, Raman scattered light, for example, four or six orders of magnitude compared to that in ordinary solutions or glass slides. The strength of is increased. Alternatively, a substance to be analyzed is mixed in a suspension in which silver or gold nanoparticles are dispersed, and the Raman scattered light is measured as it is, or the suspension is placed on a normal substrate such as a slide glass. The same effect can be obtained by measuring the Raman scattered light of the material dropped and dried. It is known that there are many factors involved in the mechanism of this luminescence enhancement phenomenon, and it cannot be said that it has been fully elucidated, but the electric field enhancement by resonance of surface plasmon plays an important role. This is certain.

[0007] Plasmon is a particle-image name, but what is actually discussed is classical electromagnetic plasma waves. Surface plasmon is a surface wave localized at the interface that decays exponentially as the interfacial force goes away, and is generally seen in metals with a negative dielectric constant in the visible to infrared region. Of the three components of the wave vector, the component perpendicular to the interface has an imaginary value, so the other two components have larger values than in free space. Ie space The wavelength is shorter than the light wave propagating through. In addition, the wavelength is determined by the structure of the material alone, and even shorter wavelengths can be realized.

[0008] The role of surface plasmons in surface-enhanced Raman scattering is reported, for example, in Reference 1 below. Lopez Rios, “The Role of Waveguide and Surface Plasmon Resonance in Surface-Enhanced Raman Scattering of Cold-deposited Metal Films” Solid State Communications, 52, 2, 197-20 Tadatoshi (T. Lopez- Rios, 'Role of waveguide and surface plasmon res onances in surface-enhanced raman scattering at coldly evaporated metallic films, s olid state communications, vol. 52, No. 2, pp.197- 201, 1984)

Disclosure of the invention

[0009] If a resonator that resonates surface plasmons is made, a minute resonator that cannot be realized by other methods can be realized. Especially for metals such as silver, gold, copper, and aluminum, the loss of light due to absorption is small, so a large Q value can be realized at the same time. This resonator has a high utility value as an analysis chip that sensitizes optical analysis by irradiating light to obtain information on the target substance force.

[0010] However, until now, such an analysis chip has not been provided with a clear design guideline, and a structure suitable for mass production has been sufficiently studied. .

The present invention uses an analysis chip that makes use of surface plasmon resonance and enables high sensitivity of analysis based on an optical signal typified by Raman scattered light, a method for manufacturing the chip, and the chip. An object of the present invention is to provide an analysis apparatus and an analysis method using the above.

[0012] The present invention provides an optical analysis chip comprising a negative dielectric, and a positive dielectric in a solid state, which is disposed inside at least one groove formed on the surface of the negative dielectric. I will provide a.

In another aspect of the present invention, there is provided a method for manufacturing the above-described optical analysis chip, wherein a convex having a groove having a predetermined dimension is pressed against a positive dielectric, thereby causing a protrusion derived from the groove. Forming a portion on the surface of the positive dielectric, forming a negative dielectric on the surface of the positive dielectric to a height exceeding the height of the convex portion, and the surface of the positive dielectric The surface of the negative dielectric is exposed from the opposite side, and a part of the positive dielectric is disposed in a groove formed in the surface of the negative dielectric derived from the convex portion. Remain Thus, there is provided a method for manufacturing an optical analysis chip comprising a step of removing a part of the positive dielectric.

[0014] Another aspect of the present invention is a method for manufacturing the above-described chip for optical analysis, comprising the step of forming a laminate in which positive dielectric thin films and negative dielectric thin films are alternately laminated, A step of disposing a negative dielectric on one side surface of the multilayer body; and polishing the multilayer body from a side surface opposite to the side surface of the multilayer body to thereby form a negative dielectric film disposed on the negative dielectric thin film and the side surface. And a step of determining a depth L of a groove in which a positive dielectric composed of the positive dielectric thin film is disposed. The method for manufacturing an optical analysis chip is provided.

[0015] From another aspect, the present invention can measure the optical analysis chip, a light source arranged to irradiate light on the surface of the optical analysis chip, and light emitted from the surface. And an optical measuring device arranged as described above.

[0016] In yet another aspect, the present invention provides a method in which a substance to be analyzed is disposed on the surface of the optical analysis chip, the surface is irradiated with light, and the light emitted from the substance to be analyzed is measured. An optical analysis method for a substance to be measured is provided.

[0017] Just by forming a groove that causes surface plasmon resonance on the surface of the negative dielectric, a minute substance to be analyzed enters the bottom of the groove. As described later, a large electric field strength due to surface plasmon resonance cannot be obtained at the bottom of the groove serving as the closed end. Therefore, in the present invention, a positive dielectric, which is a solid, is arranged inside the groove, thereby predefining the position where the analysis target substance is to be arranged.

[0018] In addition, a narrow groove having only a nanometer-level width is generally physically unstable, and an object is deposited in the groove, or atoms migrate and the groove is buried. There is concern about changes over time. Placing a solid positive dielectric inside the groove is reasonable from the viewpoint of stability as an industrial product.

Brief Description of Drawings

FIG. 1 is a schematic diagram (a) of an interface between a negative dielectric material and a positive dielectric material, and a diagram (b) showing dispersion characteristics of a surface wave mode propagating along the interface.

[FIG. 2] A schematic diagram (a) of a slab waveguide having a negative dielectric as a cladding and a positive dielectric as a core, and a diagram (b) showing dispersion characteristics of a surface wave mode propagating along the slab waveguide. 圆 3] A diagram showing the schematic structure of a closed resonator and the electric field distribution at the time of resonance. 圆 4] (a) to (c) are perspective views illustrating the structure of a closed resonator. It is.

FIG. 5 is a cross-sectional view showing an example of the optical analysis chip of the present invention.

FIG. 6 is a cross-sectional view showing another example of the optical analysis chip of the present invention.

[FIG. 7] (a) to (d) are sectional views for explaining each step in an example of the production method of the present invention.

FIG. 8 is a cross-sectional view (a) showing the dispersion state of the analyte in an untreated surface state and a cross-sectional view (b) showing the dispersion state of the analyte after the surface treatment.

[Fig. 9] (a) to (f) are cross-sectional views for explaining each step in another example of the production method of the present invention.

FIG. 10 is a diagram showing an example (a) of the reflection spectrum shown by the optical analysis chip of the present invention and an example (b) of the wavelength dependence of the electric field enhancement intensity.

FIG. 11 is an example of a reflection spectrum shown by the optical analysis chip of the present invention.

FIG. 12 is a schematic diagram showing a configuration example of an optical analysis apparatus of the present invention.

FIG. 13 is a diagram showing an example of the relationship between the wavelength λ e of the excitation light and the wavelength λ s of the signal light and the wavelength dependency of the electric field enhancement degree of the optical analysis chip.

FIG. 14 is a diagram showing another example of the relationship between the wavelength λ e of the excitation light and the wavelength λ s of the signal light and the wavelength dependence of the electric field enhancement degree of the optical analysis chip.

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] [Basic principle of sensitivity improvement]

First, the light emission enhancement effect when the optical analysis chip of the present invention functions as a “resonator” will be described.

[0021] This "resonator" has two effects. The first effect is enhancement of the incident electric field.

This is the effect that a large electric field is generated in a small area, as if the force of the incident light was intensely collected by the lens. Molecules placed in places with a large electric field are strongly excited and emit light in proportion to that. The second effect is an increase in luminous efficiency. Usually, the luminous efficiency of a substance is understood as a characteristic unique to each substance. In this case, the luminous efficiency of the substance placed in the resonator is different. In particular, molecules (dipoles) placed in places with a large electric field in the resonator emit light with high efficiency. The magnitude of the electric field in the resonator corresponds to the state density of the radiation field.

[0022] The first effect may be referred to as an effect as a receiving antenna. An antenna is a kind of resonator, and as is well known, the same antenna works as both a receiving antenna and a transmitting antenna. In addition, the performance as a receiving antenna for the same wavelength is the same as the performance as a transmitting antenna. This is explained by the reciprocity theorem. Similarly, the second effect may be understood as a transmission antenna effect. Since the light emission efficiency of molecules strongly excited by the first effect is increased by the second effect, the light emission efficiency is enhanced twice by using the resonator. In particular, in the process where a substance receives light of a predetermined wavelength and emits an electromagnetic wave with a wavelength approximately equal to that, such as Raman scattering, the enhancement as a receiving antenna (M times) and the enhancement as a transmission antenna are contradictory. Since the theorem is almost equal, the overall efficiency of this process reaches M ² times.

[0023] Let us consider what kind of resonator is necessary in order to utilize the light emission enhancement effect described above. First of all, it is necessary that the electric field enhancement is large. In order to increase the density of states, it is necessary that only a small number of modes exist in the small volume. That is, it is important that the aforementioned parcel coefficient is large. Secondly, in such a resonator, a structure that can accurately place the target substance in a place where the electric field is large is required.

[0024] Hereinafter, a method for realizing an optical analysis chip as a resonator that can satisfy both of these conditions will be described.

[0025] The physical phenomenon to be used is the resonance caused by the reflection of the surface plasmon mode of the slab waveguide, which is sandwiched by a clad made of a negative dielectric material with a slit in a minute gap, at the end face of the waveguide. It is a phenomenon. It is important that this slab waveguide does not have a finite length force comparable to the surface plasmon wavelength.

[0026] Here, the positive dielectric has a positive value in the real part of the dielectric constant, and the negative dielectric has a negative value in the real part of the dielectric constant. The positive dielectric corresponds to a general non-metallic material, and specifically includes glass, ceramics, semiconductors, polymers, liquids, and the like. Also, according to the above definition, air, other gases, and vacuum spaces can be called positive dielectrics. On the other hand, negative dielectric The body means that an object made of a specific material has the above-mentioned properties only in a specific frequency range. A typical example is a metal material having a frequency lower than the plasma frequency, that is, in the visible light or infrared light region. In addition to this, materials that exhibit resonance of large lattice vibrations such as carbon carbide and various ion crystals in the far-infrared light region to the terahertz wave region, terahertz wave region force at a frequency lower than the superconducting energy gap. There are superconducting materials in the superconducting state in the microphone mouth wave region and semiconductor materials such as silicon in which the carriers are excited.

[0027] At the interface between the negative dielectric and the positive dielectric (Fig. 1 (a)), the electric field is generally perpendicular to the interface, the electromagnetic field takes the maximum value at the interface, and exponentially as the interface force increases. There is a surface wave mode that propagates along the surface with a decaying electromagnetic field distribution. Especially for materials with a small value of the imaginary component of the dielectric constant, such surface waves can propagate over long distances. The surface wave in the case where the negative dielectric is a metal material is the surface plasmon described above.

[0028] When discussing the wavelength of such a surface wave, a dispersion curve is often considered. The dispersion curve generally has the wavenumber k on the horizontal axis and the angular frequency ω on the vertical axis (Fig. 1 (b)). Wave number is surface wave

Ρ 0

Long

比例 Proportional to reciprocal, k = 2 π / λ

表 Represented as Ρ. On the other hand, the angular frequency is the wavelength at which the electromagnetic wave propagates in vacuum (vacuum wavelength) λ 2 π ο / λ

Proportional to the reciprocal of 0, ω =

0 Expressed as 0. Where C is the speed of light in a vacuum. The shape of the dispersion curve is determined by the dielectric properties of the negative and positive dielectrics, and the dispersion curve in the visible to infrared region of a typical metal material is as shown in Fig. 1 (b).

[0029] Specifically, this curve is

k ² = (w / c) ² X ε ε / (ε + ε)

ρ 0 d m d m

It is expressed by the relationship. Where ε, ε

d m are specific dielectric constants of the positive dielectric and the negative dielectric, respectively.

Next, consider a slab waveguide (FIG. 2 (a)) having a negative dielectric as a cladding and a positive dielectric as a core.

In this system, surface wave modes at the two interfaces interact and split into coupled and anti-coupled modes. This is shown in the dispersion curve in Fig. 2 (b). The broken line is the dispersion curve in Fig. 1 (b), which is split up and down. Upper is anti-coupling mode (TM mode), lower is coupling mode (T

1

M mode). [0031] Specifically, these curves are:

(l—R) Z (l + R) = ± exp (KD) (Equation 1)

d

It is calculated as a solution of here,

K ² = k ² — (co / c) ² X ε,

d p 0 d

K ² = k ² — (ω / c) ² X ε,

m p 0 m

R = — ε K / (ε K)

d m m d

It is.

[0032] The designation of TM and the like may differ depending on the technical field.

0

In this specification, TM mode is used regardless of the description method in any field as long as it is expressed as a mode having an electric field component perpendicular to the interface of the dielectric and having no cutoff frequency.

You can specify the mode called 0 mode. Here, the cut-off frequency is the angular frequency ω that defines the boundary where the mode cannot propagate at lower frequencies.

0. In a mode with a cutoff frequency, the dispersion curve is as shown in ΤΜ mode in Fig. 2 (b).

1

The force starts where the vertical axis is not zero. In contrast, in ΤΜ mode, the dispersion curve starts from the origin.

0

It has begun. In the multiple surface wave modes of a slab waveguide with a negative dielectric as the cladding and a positive dielectric as the core, the only one that has no cutoff frequency is the ΤΜ mode.

0

[0033] The wavelength λ of the surface wave in the coupled mode (ΤΜ mode) becomes shorter as the core thickness D becomes smaller.

0 Ρ

(The wave number increases). Choosing a small D is a fraction of the wavelength in a vacuum.

0

A small λ of several tenths can be realized. This is a material with a refractive index of tens

Ρ

Although it corresponds to the wavelength of electromagnetic waves, no material with such a large refractive index is known in reality. In other words, a small λ 1S negative that cannot be obtained by increasing the refractive index.

Ρ

This can be realized with a slab waveguide with a dielectric clad and a small core thickness D.

[0034] Further, since the surface wave of this coupled mode has the same electromagnetic field symmetry as the plane wave, it can be easily excited just by irradiating the plane wave from the end face of the waveguide. It can also radiate. Note that light that is electromagnetic waves generally enters and exits the resonator with a certain angular distribution. In this specification, the average propagation direction is referred to as the main propagation direction. When such a surface wave reaches the end face of the waveguide, the surface wave is reflected and returns to the waveguide again. The reflectivity at this time increases as the core thickness D decreases. The phase relationship with respect to the incident wave depends on the state of the end face. When the tip of the end face is covered with a positive dielectric (referred to as an open end), reflection is performed with a phase correlation that maximizes the electric field at the end face, and the end face of the waveguide is covered with a negative dielectric. (Referred to as a closed end), the light is reflected with a phase relationship such that the electric field is zero at the end face.

Therefore, when one end in the propagation direction is an open end and the other end is a closed end, the length (groove depth) L of the waveguide is (1Z4U, (3/4) λ, (5/4) λ

Ρ Ρ Ρ

It becomes a resonator for surface waves with such a sharp wavelength (Fig. 3). This resonator

Ρ

V, a so-called closed resonator.

[0037] In practice, the electric field does not become strictly maximum or zero at the open end or the closed end, and some oozing occurs. Therefore, some correction is necessary for the design. By using the numerical calculation method such as the boundary element method, exact calculation of the McLuel equation can be performed to find the condition where the electromagnetic energy stored in and near the positive dielectric core is maximized. The waveguide length L, where the light just resonates, is precisely

0

Can be sought.

[0038] At this time, in order for the resonance as described above to occur efficiently in the propagation direction, it is desirable that the side surface of the core parallel to the propagation direction is an open end. When the side is an open end, there is no special condition for the resonance between the side-to-side distance W. In particular, the length of the waveguide is the length that corresponds to the first-order resonance, and W is the same small size.

0

If this is the case, this resonator will be a single-mode resonator, and it will be a high-performance microresonator that can excite specific modes efficiently and that has the ultimate small volume. As another form, if the distance w between the sides is more than half of the vacuum wavelength,

0

Even if the side surface is a closed end, resonance can be excited relatively efficiently. Figures 4 (a) to (c) list the specific structures from which the above condition forces are derived.

[0039] As described above, resonance by TM-mode end face reflection in a slab waveguide having a negative dielectric as a cladding and a positive dielectric as a core realizes a small resonator, and can interact with the outside world.

0

It is ideal as a microresonator because it is easy to act and exhibits significant resonance. Especially the core When the thickness D is less than or equal to the vacuum wavelength, a sufficiently small wavelength can be obtained at the same time.

0 P

A large electric field is obtained. Historically, this mode is comparable to other modes (e.g. TE).

0 Since the propagation loss is large, it has attracted much attention. For this reason, a method for realizing an analysis chip as simple as the present invention has been overlooked for a long time. However, when considering a small resonator, it is not necessary to discuss the propagation force for a small distance of a few wavelengths or even a few wavelengths at most, so this loss is very serious. is not a problem.

[0040] Actually, plasmon resonance at the particle contact point of agglomerates of silver and gold nanoparticles, which has been actively studied, is a slab in which each particle is a negative dielectric cladding and the gap is a positive dielectric core. The coupled waveguide mode of the waveguide can be regarded as resonating between the two open ends. Resonance when conducting at the contact point can be interpreted in the same way if a closed-type resonator is formed. The present invention extracts the essential mechanism of the giant resonance that occurs by chance in silver and gold nanoparticle aggregates, and provides design rules for the structure to artificially generate in an optimal form. Based on this! It has an aspect that makes optical analysis highly sensitive.

[0041] [Configuration of optical analysis chip]

The chip for optical analysis according to the present invention includes a negative dielectric and a positive dielectric in a solid state and disposed in at least one groove formed on the surface of the negative dielectric. FIG. 5 shows the simplest configuration example of the optical analysis chip of the present invention. On the surface la of the negative dielectric 1, a groove having a rectangular cross section is formed, and the positive dielectric 2 is disposed up to a predetermined height inside the groove of the bottom force of this groove. The surface 2a of the positive dielectric 2 serves as a table on which the analyte 3 is placed. The substance 31 to be analyzed placed on the table is irradiated with light 31, and the signal light 32 emitted from the substance 3 as a result of this irradiation becomes the object of measurement.

As shown in FIG. 6, the optical analysis chip of the present invention includes a positive dielectric 2 arranged inside two or more grooves formed on the surface of the negative dielectric 1, and includes two or more grooves. May be arranged in parallel with each other. In this analysis chip, grooves having a width D are regularly (periodically) arranged at a predetermined interval P. If there are a plurality of positive dielectrics 2 in the groove, the substance 3 to be analyzed is positioned on the positive dielectric 2 with a certain probability simply by spreading. If this form is used, the minute analyte 3 is arranged on the positive dielectric 2 inside the groove having a minute width. t Difficult work is unnecessary.

Hereinafter, preferred dimensions of the optical analysis chip will be exemplified with reference to FIG. 4 and FIG.

[0044] Preferably, the groove width D is smaller than the groove depth L and the groove length W! /. The width D of the groove is specifically 50 nm or less, particularly lOnm or less, for example 0.2ηπ! ~ LOnm is preferred. The depth L of the groove is preferably 1 nm to 500 nm, for example. The ratio of the groove depth L to the groove width D may be 10 or less. Since this ratio does not need to be extremely high, the formation of the grooves is relatively easy. The vacuum wavelength of the target light is 300ηπι〜4 / ζ πι

0

You should also choose your strength.

[0045] The groove length W may be set to 1Z2 or more of the target wavelength λ, for example, 500ηπ! ~

0

It may be in the range of 5 / z m. In addition, in the length direction of the groove, both end faces of the groove may be covered with a negative dielectric material! / (Figure 4 (a)), and at least one of them is covered with a negative dielectric material! / (Fig. 4 (b) (c)).

[0046] The resonance wavelength λ in this groove is mainly the groove width D, groove depth L, and groove spacing P.

0

Can be controlled. The sharpness of the resonance peak appearing at λ is mainly due to the groove width D and the order of resonance.

0

The force determined by the dielectric constant of the negative dielectric material has a certain extent of spread, and the wavelength range where the resonance enhancement effect is obtained is determined according to the extent of this spread. The broadening of the wavelength range is about lOOnm when expressed by the half-width of the first-order resonance peak when D = lOnm and the negative dielectric is gold. The actual enhancement effect differs depending on the size of the peak, but here, the wavelength region defined by the half width is considered to be the wavelength region where the enhancement effect due to the peak can be obtained. The groove depth L, interval P, and width D are determined by the resonance of TM mode surface waves.

0

It is desirable to set so that the intensity of light having a wavelength in a predetermined wavelength region (including the target wavelength) is enhanced.

[0047] When it is not necessary to substantially consider the resonance interaction between adjacent grooves and the influence of surface waves on the surface of the negative dielectric, the light intensity is increased in a predetermined wavelength range including the target wavelength. The most important parameter that should be properly set is the groove depth L. Specifically, the depth L of the groove may be defined as ((2η−1) Ζ4) λ. Where η is preferably 6 or more

Ρ

Lower, more preferably a natural number of 3 or less, and λ is the wavelength of the surface wave (in TM mode)

P 0

. The wavelength λ of the TM mode surface wave is the target wavelength λ, groove width D, negative dielectric And the relative dielectric constant of the positive dielectric.

[0048] When the groove depth is set as described above, the electric field becomes maximum at the opening end of the groove at the same height as the surface of the negative dielectric in the groove depth direction (Fig. 3). Therefore, in this case, the negative dielectric surface la should coincide with the positive dielectric surface 2a! /, (Figs. 5 and 6).

However, in practice, as described above, the surface plasmon mode (mode propagating in the P direction in FIG. 6) on the light incident surface (the surface of the negative dielectric) and the surface plasmon mode (L The mode at which the electric field is maximized may deviate from the surface of the negative dielectric material. Dispersion characteristics in the new resonance mode generated in this way can be solved by strictly solving the Maxwell equation using the transfer matrix method and the multimode expansion method. Based on the calculation results, the surface of the positive dielectric 2a The position of may be near the height at which the electric field is maximized.

[0050] As described above, when a new resonance mode occurs, the position where the amplitude of the electric field becomes maximum is approximately L of the negative dielectric surface la (groove opening end) toward the bottom of the groove. The range is 0.6 times or less, and in many cases 0.5 times or less of L.

[0051] An analysis chip in which the positive dielectric 2 is filled so that the surface 2a thereof is substantially the same height as the surface la of the negative dielectric is a preferred form of the present invention. As described above, the height of the surface 2a of the positive dielectric may be adjusted as appropriate. Here, “substantially the same” means that the difference in height between the surface 2a of the positive dielectric and the surface la of the negative dielectric is 10% or less of the depth L of the groove.

[0052] Negative dielectric materials and positive dielectric materials are exemplified below. A typical negative dielectric material is a metal. The negative dielectric made of metal may contain, as a main component, at least one selected from gold, silver, copper, and aluminum, for example. Here, the main component means a component having the highest content. For example, the main component of the negative dielectric material in which the total content of gold and silver exceeds the total content of other components is the two components of gold and silver.

[0053] The positive dielectric is preferably composed of at least one selected from the forces applicable to the various materials exemplified above, for example, a resin and an inorganic material. Here, the inorganic material includes a semiconductor material, and further includes various inorganic compounds such as oxide, nitride, carbide, nitride, chloride, and fluoride. Inorganic materials include, for example, silica (acid silicate), acid silicate Titanium, niobium oxide, aluminum oxide, zinc oxide, tantalum oxide, magnesium oxide

Further, at least one selected from the group consisting of acid hafnium and magnesium fluoride power can be exemplified. Examples of the resin include polystyrene, polymethylmetatalylate (acrylic resin), and polycarbonate.

[Specific Example and Characteristics of Optical Analysis Chip]

Specific examples of dimensions and characteristics of optical analysis chips are introduced. A typical structure is D = 10nm, L = 60nm, W = 3 / zm, negative dielectric is gold, and positive dielectric filling the negative dielectric groove is silica with ε = 2.1. Consider a single closed resonator. Time domain d

As a result of calculation by the domain difference (FDTD) method, the first order is λ = 1. 27 111, the second order is λ = 615 nm.

0 0

It was very powerful to show the resonance. The reflection spectrum obtained by calculation is shown in Fig. 10 (a).

[0055] A sample corresponding to this was laminated with a multilayer film of gold, silica, and gold, and the surrounding area was removed with a focused ion beam device leaving a rectangular region slightly larger than the predetermined L and W, and the closed end side was removed. Gold was vapor-deposited from a direction of 45 degrees, and it was attached to the focused ion beam device once again, and L and W were processed by finishing. The finished dimensions were D = 14nm, L = 63nm, W = 3m. When the reflection spectrum was measured, the second-order resonance at λ = 605 nm

0

Since a reflection valley corresponding to is observed (the 1st order was not observed directly outside the measurable wavelength region), it was confirmed that the calculation and the experiment agreed relatively well even with a closed resonator. did it.

[0056] According to the calculation, the electric field enhancement at the center of the incident end face of the core (denoted by the square of the electric field amplitude IEI corresponding to the intensity) is as shown in Fig. 10 (b). The primary was 2270 times and the secondary was 80 times. The fine force between the first and second order, the peak is the resonance due to the surface plasmon with the W component. If the core is reduced by an order of magnitude and D = lnm, the amplitude of the electric field is inversely proportional to D. Therefore, the intensity is increased by 100 times that is more than 5 orders of magnitude in the first order and 3 to 4 orders of magnitude in the second order. . In the Raman scattering process, both the incident wave and the scattered wave receive such an increase, so it is expected that the Raman enhancement will be 10 orders of magnitude or more in the first order and 7 orders of magnitude in the second order. This is a performance that is an order of magnitude higher than conventional analysis chips that can not be obtained by two orders of magnitude, and it is possible to achieve an increase in strength comparable to silver and gold nanoparticle aggregates. Become.

[0057] [First specific example of manufacturing method of optical analysis chip] The structure of the analysis chip according to the present invention is industrially superior in that it can be mass-produced at low cost by applying the nanometer-level mold transfer technology, which has been developed recently, which is generally called nanoimprint technology. This analysis chip has a structure in which a positive dielectric solid material is embedded in a groove having a width D and a depth L of a surface of a negative dielectric, for example, a metal material. As in the previous example, it is desirable that the value of D be as small as lOnm or less, but the value of L is the same size, and the aspect ratio (LZD) is not necessarily high. Specifically, it is 6 in the previous numerical example and 10 at most. Unlike nanostructures with aspect ratios greater than 10, many technologies can be applied if the aspect ratio is 10 or less.

[0058] Figures 7 (a) to 7 (d) show the manufacturing process of a high-sensitivity analysis chip based on the mold transfer technology. In this process, a mold having a predetermined groove formed on the surface is used. Since only one mold is required, the manufacturing process may be performed using an electron beam lithography technique or the like that is poor in mass productivity. This mold is transferred to a mold material made of, for example, a resin to obtain a resin 50 having protrusions 25 having a width D and a height L (FIG. 7 (a)). Between the protrusions 25, a groove 15 having a width P is formed.

[0059] A number of methods have been proposed for this process. For example, a method in which a mold is pressed on a flat plate such as acrylic resin while the temperature is simply raised, a laser pulse is irradiated from the mold side with a transparent mold pressed against the flat resin plate, and the temperature is increased instantaneously. The method of transferring the shape of the mold, applying a liquid UV curable resin on the substrate, pressing the mold, and then irradiating the mold with UV light from the side of the transparent mold to cure the resin. is there.

[0060] Since the efficiency decreases when incident light is diffracted on the surface of the negative dielectric, it is generally preferable to use P + D to prevent diffraction from occurring at the target wavelength. Enter

0 0

Even when the incident light has an angular distribution, diffraction does not occur if P + D <λ Ζ2.

0

P + D is preferably set to 100 to 250 nm, for example.

Next, a negative dielectric thin film 1 is formed on the surface of the resin 50 by applying a film forming technique such as a direct current magnetron sputtering method (FIG. 7 (b)). Examples of the negative dielectric thin film 1 include a gold thin film having a thickness of 150 nm. As a film forming method, a method and conditions with high step coverage should be selected so that the negative dielectric is sufficiently filled in the groove 15 of the mold 50. On the surface of the negative dielectric thin film 1, grooves 11 and protrusions 21 are formed reflecting the protrusions 25 and grooves 15 of the mold. Subsequently, the negative dielectric thin film 1 is bonded to the substrate 20 using an adhesive 30 such as epoxy resin (FIG. 7 (c)). As long as the substrate 20 can support the thin film 1, the material thereof is not particularly limited, and may be glass, silicon, metal, or the like.

[0063] Finally, the resin 50 is mechanically polished to some extent from the surface opposite to the surface on which the negative dielectric thin film 1 is formed, and further, using various organic solvents (xylene, toluene, etc.) In addition to the groove 11 of the negative dielectric thin film 1, the resin 50 is also removed (FIG. 7 (d)). The removal of the resin 50 with a solvent needs to be performed at least to the extent that the top surface of the protrusion 21 of the negative dielectric thin film 11 is exposed.

[0064] Thus, the negative dielectric having a surface in which the grooves 11 having the depth L and the width D are regularly arranged in parallel with each other at a distance P, and the grooves 11 are filled with the resin as the positive dielectric 2. An analysis chip with 1 is obtained.

[0065] It should be noted that the thickness T of the negative dielectric thin film 1 where the groove 11 is formed has a thickness that is such that the electric field is sufficiently attenuated inside the negative dielectric and the resonance characteristics are not affected by the opposite surface! This is preferred. The thickness of T is preferably lOOnm or more. However, T need not be larger than necessary. The strength of the analysis chip may be ensured by the substrate 20 bonded to the negative dielectric 1 on the surface opposite to the surface where the grooves 11 are formed. Considering this, the thickness of T may be 1 μm or less.

[0066] For the reasons described above, in the structure in which a plurality of grooves as shown in FIG. 7 (d) are arranged, a new plasmon resonance state occurs, and the position where the electric field becomes maximum is the surface force of the negative dielectric 1. May shift. In this case, optimize the dissolution conditions with an organic solvent and retract the surface of the positive dielectric (wax) 2 to an appropriate position inside the groove 11.

[0067] Further, the analysis chip may be subjected to a surface treatment. For example, the surface of the positive dielectric 2 and the surface of the positive dielectric 2 are negative so that the surface of the positive dielectric 2 is relatively hydrophilic compared to the surface of the negative dielectric 1, or is relatively hydrophobic. When an appropriate surface treatment is applied to at least one of the surface forces of the dielectric 1, the distribution of the analyte on these surfaces can be easily controlled.

[0068] For example, when the analysis target substance is supplied in the form of an aqueous solution, the analysis target substance 3 is distributed almost evenly when not processed (Fig. 8 (a)), but the surface of the negative dielectric 1 When the surface of the positive dielectric 2 is made hydrophilic, the analyte 3 is densely attached to the surface of the positive dielectric 2. (Fig. 8 (b)). For example, the entire surface of the analysis chip obtained according to the above-described process is hydrophilized by oxygen plasma treatment, and then the surface is immersed in 1-decanethiol ethanol solution and rinsed with ethanol. 1-decane thiol is adsorbed only on the surface, and only the surface of negative dielectric 1 is hydrophobized. Such surface treatment is effective in analyzing a very small amount of the target substance.

[0069] Conversely, if the analyte is likely to be adsorbed on the hydrophobic surface, the surface of the analysis chip is immersed in an ethanol solution of 3-mercaptopropionic acid without performing oxygen plasma treatment for hydrophilicity. Rinse with ethanol. 3-mercaptopropionic acid is adsorbed only on the surface of negative dielectric 1 (gold), and only the surface of negative dielectric 1 is hydrophilized due to the carboxyl group at the end. Since the surface of one positive dielectric 2 is inherently hydrophobic, the substance 3 to be analyzed is densely distributed on the surface of the positive dielectric 2.

[0070] [Second specific example of manufacturing method of optical analysis chip]

The optical analysis chip of the present invention can also be produced by applying a thin film forming technique. For example, first, a 150 nm thick gold thin film as the negative dielectric thin film 5 and a silica thin film with a thickness D as the positive dielectric thin film 2 are alternately laminated several times on the synthetic quartz substrate as the substrate 61. A multilayer film (multilayer structure) 71 is formed (FIG. 9 (a)).

Next, the substrate 61 is cut into a strip shape with a width of about 2 mm, for example. As a set of two sheets, the multilayer structure parts are faced to each other, and bonded together with a hard epoxy resin that becomes the bonding layer 73. Thus, a laminated body is obtained in which the first substrate 61, the first multilayer structure 71, the bonding layer 73, the second multilayer structure 72, and the second substrate 62 are laminated in this order (FIG. 9B).

[0072] The reason why the multilayer structures 71 and 72 are bonded together is that the peripheral portion tends to be polished quickly in the subsequent polishing step. When polishing without bonding, the delicate multilayer structure 71, 72 becomes the outermost periphery, and high-precision polishing becomes difficult. Multi-layered structures 71 and 72 are bonded together and placed in the center of the polishing material to facilitate high-precision polishing.

[0073] Further, the laminate is thickened, for example, cut to about 300 m, and attached to a polishing jig with hot wax, and one side is polished (FIG. 9 (c)). For polishing, for example, mirror finishing may be performed by first polishing with water-resistant abrasive paper and then with diamond paste. Furthermore, a technique such as flat milling using argon ions may be used. Continue to multilayer On one of the end faces of the structures 71 and 72, gold having a thickness of 150 nm is deposited as the negative dielectric thin film 40, and this end face is used as a closed end (FIG. 9 (d)).

[0074] After that, this laminate is bonded to a glass substrate as a support 20 using an adhesive 30 (Fig. 9 (e)). As the materials for the adhesive 30 and the support 20, those exemplified above may be used. Finally, the support 20 is attached to the polishing apparatus and polished in the same process as above, the end faces of the multilayer structures 71 and 72 are retracted, and the thickness (groove depth) L ′ is reduced to the predetermined dimension L. (Fig. 9 (f)).

In this way, an analysis chip can be obtained in which the positive dielectric thin film 3 filled in the grooves formed by the negative dielectric thin films 5 and 40 has an exposed surface (side surface of the multilayer structure) force.

[0076] It is desirable that the thickness L be manufactured with an accuracy of nanometer order. For this purpose, measure the reflection spectrum and transmission spectrum of the polished surface as needed during polishing, and polish until the desired spectrum is obtained.

[0077] By using the thin film formation technique, a thin positive dielectric thin film that defines the width D of the groove can be formed with high accuracy and good reproducibility. The manufacturing method exemplified above is suitable for mass production of analysis chips in which the groove width D is controlled to be small in order to obtain a high enhancement effect.

[Description of Analytical Apparatus and Analysis Method]

FIG. 12 shows an example of the analysis apparatus of the present invention. This device is capable of detecting the optical analysis chip 10, the light source 41 arranged so that the excitation light 31 can be irradiated on the surface of the optical analysis chip 10, and the signal light 32 emitted from the chip surface. And an optical measuring instrument 42 arranged. The analyte 3 is arranged on the surface of the optical analysis chip 10 so that at least a part thereof is located on the positive dielectric 2 arranged inside the groove formed on the surface of the negative dielectric 1. Has been. The excitation light 31 is preferably irradiated along the main propagation direction (for example, the direction perpendicular to the surface) of the incident light that is predetermined for the optical analysis chip 10.

[0079] The light source 41 may be a monochromatic light source such as a laser, regardless of whether the signal to be measured is Raman scattered light, fluorescence, or harmonic light. Described in relation to the wavelength e of light 31 emitted from the light source 41, the groove depth D of the optical analysis chip is preferably 1Z10 times or less of the groove depth L is less than the wavelength e. Preferably there is. The light source 41 is a straight line A polarized light source is preferred. In that case, it is desirable to adjust the polarization direction (the direction of the electric field) to match the width direction of the groove of the analysis chip.

[0080] Specifically, the optical measuring instrument 42 may be a combination of a spectroscope and a photodetector.

When the signal to be measured is Raman scattered light emitted from the analyte, the analyte is identified, the molecular state is examined, or the concentration is measured by measuring the spectrum. However, if the analysis target is narrowed down and you want to know the amount and ratio of Raman scattered light and fluorescence power, you can fix the spectrometer and measure only the intensity in a specific wavelength range. Instead of using a filter with a predetermined transmission spectrum, simply measuring the light intensity transmitted through it. Even when harmonic light is measured, a filter is sufficient because the measurement wavelength is determined by the excitation light wavelength. In these cases, the optical measuring instrument 42 may include a filter and a photodetector having a predetermined transmission spectrum.

Hereinafter, a method for selecting the excitation light wavelength, the signal light wavelength, and the resonance wavelength of the analysis chip will be described. The analysis chip according to the present invention can have various resonance characteristics depending on the width D, depth L, and interval P of the slit. D mainly gives enhancement, and if D is fixed, the resonance wavelength is determined by L and P. The sharpness of resonance is mainly determined by the slit width D, the order of resonance, and the dielectric constant of the negative dielectric used.

[0082] The half width of the resonance peak was 125 nm in the example shown in Fig. 10 (b). If there is such a half-width, when the signal to be measured is Raman scattered light, both the excitation light wavelength e and the signal light wavelength s are within this range. For example, when e = 633 nm, the generally noted Raman shift (Stokes light) is at most 2000 cm ¹ or less. This corresponds to a maximum of s = 725 nm. The difference between λ s and e is at most 92 nm, which is just enough to fit in one resonance peak. Therefore, in order to select an analysis chip, it is only necessary to aim for the resonance peak of the analysis chip to be λ e, s, or an average value of both. Even when the signal to be measured is fluorescence, the same can be considered in the case of a system in which the difference between s and e (Stokes shift) is small.

[0083] However, when the signal to be measured is fluorescent and the stochastic shift is large! /, Or in the case of harmonic light, both s and e cannot be contained in one resonance peak. In that case, the analysis chip should be placed so that the resonance peaks of different orders correspond to s and λ e respectively. Just choose.

[0084] For example, among the prototype resonators with D = 56nm and L = 208nm, as shown in Fig. 11, from the valley position of the reflection spectrum, X = 545nm, 3rd order, λ = 763nm, 2 Next

0 0

It turns out that there is a cry peak. This is very close to the absorption maximum wavelength 542 nm and emission maximum wavelength 754 nm of the methanol solution of the dye LDS751, respectively. In such a case, for example, if measurement is performed with excitation light of e = 532 nm, the excitation light is enhanced by the third-order resonance, and the emission is also enhanced by the second-order resonance. In addition, a double enhancement can be obtained. Although the enhancement effect by surface plasmon should be seen in various light emission processes, only reports of enhancement of Raman scattered light are prominent, and the increase in intensity is prominently formed accidentally. In the resonance state, in the case of the Raman scattering process, both s easily fit in one resonance peak, whereas for fluorescence and harmonic light, the probability that both s fall in the resonance peak respectively. It is thought that this is because one of the enhancement effects and powers cannot be obtained. However, when the analysis chip according to the present invention is used, an optimum chip can be designed and realized in accordance with the target light emission process, so that double enhancement can be easily obtained even in light emission processes other than Raman scattered light. You can. Figure 14 shows an example of the peak due to resonance using an analysis chip suitable for measuring fluorescence and harmonic light. In Fig. 14, corresponding to (1/4) λ, (3/4) λ, and (5/4) λ in order from the right.

Ρ Ρ Ρ

The peak to be shown is shown.

[0085] As described above, the optical analysis method of the present invention is suitable as a method for irradiating light having a wavelength λe and measuring light having a wavelength λs different from λe emitted from the analyte. ing. The light having a wavelength s may be Raman scattered light, fluorescent light, or harmonic light having a wavelength e.

[0086] According to the optical analysis method of the present invention, a) generated by irradiation with light having a wavelength λe

B) TM mode generated by the emission of light having a wavelength of s

0 0 surface wave, force By the resonance of at least one selected surface wave, the intensity of the signal light having the wavelength S can be enhanced as compared with the case where there is no resonance. According to the optical analysis method of the present invention, the intensity of light having the wavelength e is enhanced by the resonance of the surface wave of a), and the intensity of light having the wavelength λ s is enhanced by the resonance of the surface wave of b). It is also possible. [0087] In the optical analysis method of the present invention, in the optical analysis chip, the groove is a TM mode surface.

0

The resonance of the wave is formed so that the intensity of light in at least one wavelength region is enhanced inside the groove, and both s are included in the same wavelength region selected by the at least one wavelength region force. (See Fig. 13). In the optical analysis method of the present invention, in the optical analysis chip, the groove has an electric field component in the width direction of the groove, and in the groove due to resonance of the surface wave having no cutoff frequency. It may be formed so that the intensity of light in two or more wavelength ranges is enhanced, and s may be selected from the above two or more wavelength range forces and included in different wavelength ranges. (See Figure 14).

[0088] The power described in the embodiments of the present invention has been described above. The present invention can be implemented in various other forms without departing from the spirit thereof. For example, in the above example, when selecting an appropriate analysis chip for and h, it was described that different chippers made under different conditions should be selected as appropriate. However, since the analysis chip according to the present invention can be batch-produced by the transfer technology, it is useful to arrange a number of resonator arrays with various conditions on a single chip and select a convenient one from them. Is further increased. Such a complex analysis chip is also a simple extension of the present invention and is merely an example of the present invention.

Industrial applicability

[0089] The present invention has great utility value as contributing to high sensitivity of analysis based on optical signals such as Raman scattered light, fluorescence, and harmonic light.

Claims

The scope of the claims

[I] An optical analysis chip comprising: a negative dielectric; and a positive dielectric in a solid state disposed in at least one groove formed on the surface of the negative dielectric.

[2] The positive dielectric in a solid state is disposed inside two or more grooves formed on the surface of the negative dielectric, and the two or more grooves are disposed in parallel to each other. Chip for optical analysis as described in 1.

[3] The chip for optical analysis according to claim 1, wherein a width D of the groove is smaller than a depth L of the groove and a length W of the groove.

4. The optical analysis chip according to claim 1, wherein the width D of the groove is 50 nm or less.

[5] D is 0.2ηπ! 5. The chip for optical analysis according to claim 4, wherein the chip is lOnm.

6. The optical analysis chip according to claim 1, wherein the depth L of the groove is 1 μm or less.

[7] L is Inn! The chip for optical analysis according to claim 6, wherein the chip is ˜500 nm.

[8] A wave having a depth L in the predetermined wavelength region inside the groove due to resonance of a surface wave having an electric field component in the width direction of the groove and not having a cutoff frequency. 2. The chip for optical analysis according to claim 1, which is set so that the intensity of light having a length is increased.

[9] The optical analysis chip according to [8], wherein the depth L of the groove is ((2η-1) / 4) λ.

Ρ

Where η is a natural number and λ is the wavelength of the surface wave.

Ρ

[10] The groove depth L, the groove spacing P, and the groove width D have V electric field components in the width direction of the groove and do not have a cutoff frequency. 3. The chip for optical analysis according to claim 2, which is set so that the intensity of light having a wavelength in a predetermined wavelength region inside the groove is enhanced by resonance of surface waves.

[II] The optical analysis chip according to claim 1, wherein the two end faces of the groove in the length direction of the groove are not covered with a negative dielectric.

12. The optical analysis chip according to claim 1, wherein at least one of the two end faces of the groove in the length direction of the groove is covered with a negative dielectric.

13. The optical analysis chip according to claim 1, wherein the negative dielectric is made of metal.

[14] The metal is composed mainly of at least one selected from gold, silver, copper and aluminum force. The optical analysis chip according to claim 13.

[15] The positive dielectric is made of at least one selected from a resin and an inorganic material.

The optical analysis chip according to 1.

[16] The optical analysis chip according to claim 1, further comprising a base bonded to the negative dielectric on the surface opposite to the surface.

17. The optical analysis chip according to claim 1, wherein the surface of the positive dielectric has substantially the same height as the surface of the negative dielectric in the depth direction of the groove.

[18] At least one selected from the surface of the positive dielectric and the surface of the negative dielectric so that the surface of the positive dielectric is relatively hydrophilic compared to the surface of the negative dielectric 2. The optical analysis chip according to claim 1, wherein the surface treatment is performed.

[19] At least one selected from the surface of the positive dielectric and the surface of the negative dielectric so that the surface of the positive dielectric is relatively hydrophobic compared to the surface of the negative dielectric 2. The optical analysis chip according to claim 1, wherein the surface treatment is performed.

[20] A method for manufacturing an optical analysis chip according to claim 1,

Forming a convex portion derived from the groove on the surface of the positive dielectric by pressing a mold in which a groove having a predetermined dimension is formed on the positive dielectric;

Forming a negative dielectric material on the surface of the positive dielectric material to a height exceeding the height of the convex portion;

In a state where the surface of the negative dielectric is exposed from the opposite side of the surface of the positive dielectric and is disposed in a groove formed on the surface of the negative dielectric derived from the convex portion. A step of removing a part of the positive dielectric so that a part of the positive dielectric remains.

21. The method for manufacturing an optical analysis chip according to claim 20, wherein the positive dielectric is made of a resin.

[22] The method for producing an optical analysis chip according to claim 1,

A step of forming a laminate in which positive dielectric thin films and negative dielectric thin films are alternately laminated, a step of disposing a negative dielectric on one side surface of the laminate,

The positive dielectric thin film is formed from the negative dielectric thin film and the negative dielectric disposed on the side surface by polishing the multilayer from the side opposite to the side of the multilayer. A step of determining the depth L of the groove in which the positive dielectric is arranged,

A method for manufacturing a chip for optical analysis, comprising:

23. The method for manufacturing an optical analysis chip according to claim 22, wherein the positive dielectric thin film is made of an inorganic material.

[24] The optical analysis chip according to claim 1, a light source arranged so as to be able to irradiate light on a surface of the optical analysis chip, and a light emitted from the surface force. And an optical analyzer.

25. The optical analysis device according to claim 24, wherein the light source is a monochromatic light source.

26. The apparatus for optical analysis according to claim 24, wherein the optical measuring instrument includes a spectroscope and a photodetector.

27. The optical analysis device according to claim 24, wherein the optical measuring instrument includes a filter having a predetermined transmission spectrum and a photodetector.

28. The optical analysis device according to claim 24, wherein a width D of the groove in the optical analysis chip is 1 to 10 times or less of a wavelength λe of light emitted from the light source.

29. The optical analysis device according to claim 24, wherein a depth L of the groove in the optical analysis chip is not more than a wavelength λe of light irradiated from the light source.

[30] An analyte is disposed on the surface of the optical analysis chip according to claim 1,

An optical analysis method for a substance, wherein the surface is irradiated with light, and the light emitted from the substance to be analyzed is measured.

[31] irradiating with light having wavelength λ e

Measuring light having a wavelength λ s different from λ e emitted from the analyte;

The optical analysis method according to claim 30.

32. The optical analysis method according to claim 31, wherein the light having the wavelength λ s is Raman scattered light.

33. The optical analysis method according to claim 31, wherein the light having the wavelength λ s is fluorescence.

34. The optical analysis method according to claim 31, wherein the light having the wavelength λs is a harmonic light of the light having the wavelength λe.

[35] a) A surface wave generated by irradiation with light having the wavelength λe, and the width direction of the groove B) a surface wave that does not have a cutoff frequency, and b) a surface wave that is generated by the emission of light having the wavelength λ s and has an electric field component in the width direction of the groove. And resonance of at least one surface wave selected from surface waves having no cutoff frequency,

32. The optical analysis method according to claim 31, wherein the intensity of light having the wavelength s is enhanced as compared with the case where there is no resonance.

[36] The intensity of light having the wavelength λ e is enhanced by the resonance of the surface wave of a), and

36. The optical analysis method according to claim 35, wherein the intensity of light having the wavelength λ s is enhanced by resonance of the surface wave of b).

[37] In the optical analysis chip, the groove has an electric field component in the groove width direction and has at least one wavelength region inside the groove due to resonance of a surface wave having no cutoff frequency. Formed so that the intensity of some light is enhanced,

37. The optical analysis method according to claim 36, wherein both λ e and λ s are included in the same wavelength range selected by the at least one wavelength range force.

[38] In the optical analysis chip, the groove has an electric field component in the groove width direction and has a wavelength region of 2 or more inside the groove due to resonance of a surface wave having no cutoff frequency. Formed so that the intensity of light is enhanced,

The optical analysis method according to claim 36, wherein the and s are selected from the two or more wavelength ranges and are included in different wavelength ranges.