JP3047048B2 - Wall jet type electrochemical detector and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall jet type electrochemical detector applied to a flow cell or a liquid phase chromatography, and a method for producing the same.

[0002]

2. Description of the Related Art In general, in a blood sugar level measurement or the like, a device called a flow cell is used which injects a sample into a carrier solvent flowing at a constant flow rate and measures the sample by a detector arranged in a flow path. In liquid phase chromatography,
A column for chromatography is inserted between the sample inlet and the detector, where the injected sample is separated,
Detected for each component.

As a method for detecting this sample, there are known a spectroscopic method such as ultraviolet and visible light, a refractive index measurement, a conductivity measurement, and an electrochemical method. In the electrochemical method, an electrode is placed in a flow path, a certain potential is applied to the electrode, and when a sample flowing on a carrier reaches the electrode, the current generated by the oxidation-reduction reaction between the electrode and the sample flows. Is detected by monitoring. As described above, the electrochemical detector is simple and relatively sensitive, and does not respond to substances which are electrochemically inactive or have a redox potential higher than the applied potential. Can be selectively detected.

[0004] Electrochemical detectors include thin-layer type, cylindrical type,
There are various shapes such as the wall jet type. Among them, the wall jet type electrochemical detector, which has a structure in which the carrier solution is sprayed vertically from the upper surface to the electrode surface, is a detector formed on the electrode surface. The thickness of the diffusion layer of the substance is small, and it shows characteristics superior to detectors of other structures in terms of detection sensitivity.

On the other hand, since the reaction site is covered with an inactive site by a protein, an enzyme, or the like, a molecule that cannot directly contact the electrode or a high oxidation-reduction potential exceeds the normal measurement limit. There is known a method of modifying (coating) an electrode surface with a functional material in order to detect a substance. That is, an electrode is modified with a catalyst having molecular selectivity such as an enzyme for detecting and quantifying an extremely low concentration of ions and molecules and detecting specific molecules. For example, using an electrode modified with glucose oxidase,
Since the enzyme reacts only with glucose, only glucose in the sample can be quantified by electrochemically detecting the generated hydrogen peroxide with an electrode.

[0006]

However, pharmaceuticals and neurotransmitters in the living body, which are currently required to be detected pathologically or biologically, have a very small abundance and are used for measurement. Due to the limited amount of sample available, there is a need for the development of more selective and sensitive detectors. In particular, when detection is performed using a surface-modified electrode, the reaction of the detection substance on the electrode is unlikely to occur since the electrode surface is covered with the modified coating. For example, in the detection of glucose by glucose oxidase, since the electrode surface is coated with an enzyme film, problems such as low sensitivity and slow response due to the difficulty of hydrogen peroxide generated by the enzyme reaction reaching the electrode surface. is there.

In the case of a sample in which a reaction site of an enzyme or the like cannot directly contact the electrode or a sample having a high redox potential, a low molecular weight redox active substance called a mediator is mixed or chemically bonded to the electrode surface. A method has been adopted in which this is immobilized on an electrode, the sample is once redox-reduced by a mediator, and the mediator reacts on the electrode to detect the target substance.
However, also in this case, since the mediator is in the solid film, there are problems such as low transmission speed, low sensitivity, and low response speed.

[0008] In a system such as a flow cell for measuring an analyte sample contained in a part of a flow of a carrier solvent, if a detector having a slow response speed is used, the response current in the carrier may be increased before the response current reaches a peak. Since the sample concentration starts to decrease, the detection sensitivity decreases. Also, when continuously measuring a large number of samples, it is necessary to wait for the response of the previous sample to be completed before performing the next measurement. Will decrease. Furthermore, when simultaneous measurement of multiple components is performed by liquid phase chromatography, the current peaks appear continuously, so the peaks of each component overlap on the electrode with a modified surface, which lowers the sample separation ability and detection sensitivity. Would.

In order to solve these problems, if a micro-comb electrode is used as the working electrode of the electrochemical detector, the contact time between the detection substance and the electrode is shortened, and a sharp electrode response can be obtained. Also, at least one pair of interdigitated comb-shaped working electrodes is used, one of the working electrodes is modified with a substance having a catalytic action or a redox action, and the active substance generated by the catalytic action or the redox action is adjacent to an unmodified one. Detecting with the working electrode enables high-speed and high-sensitivity measurement without being restricted by the mass transfer rate in the modified coating. Therefore, it is expected that a detector for a flow cell with extremely high sensitivity and selectivity will be developed by incorporating a micro-modified electrode into a wall jet type electrochemical detector.

However, in the above-described wall-jet type electrochemical detector, the carrier solution is sprayed onto the wall surface on which the electrode is present, and then flows while spreading concentrically along the wall surface. Then
It was impossible to flow the carrier solution only in the direction perpendicular to the respective strip-shaped conductive thin films constituting the electrodes. Therefore, as the flow direction deviates from the direction perpendicular to the strip electrode, the length of the electrode in the flow direction increases, and accordingly, the contact time between the detection substance and the electrode increases, and the response at the electrode slows down. Resulting in. In addition, when the detection sensitivity of an electrode obtained by modifying a functional material using a pair of interdigitated comb-shaped electrodes is improved, a conventional linear electrode uses a modified electrode and a reactive species generated by the modified electrode. Since the direction of the arrangement with the electrode to be detected does not match the direction of the flow of the carrier solvent, active species generated at one electrode due to an enzymatic reaction or the like are not efficiently detected at the other electrode, and the detection sensitivity is greatly increased. No improvement could be achieved.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a wall jet type electrochemical detector capable of obtaining high detection sensitivity and a method of manufacturing the same. It is in.

[0012]

In order to achieve the above object, a wall jet type electrochemical detector according to the present invention is different from a conventional comb-like electrode in which a linear strip-shaped conductive thin film is arranged, and has an insulating property. Composed of a plurality of concentric thin film electrodes formed on a conductive substrate, each thin film electrode is separated by a minute planar interval and / or a minute interval due to a three-dimensional step via an insulating layer, and at least the surface of each thin film electrode is separated. A part is exposed, and at least one part of the thin-film electrode is covered with a substance having a catalytic action or a redox action. Further, the method of manufacturing a wall jet type electrochemical detector according to the present invention comprises forming a thin film electrode pattern, a lead and a connection pad on an insulating substrate, and then leaving only the thin film electrode pattern and the connection pad. Then, a substance having a catalytic action or a redox action is deposited on at least a part of the thin film electrode. Further, in forming the concentric electrodes, a plurality of insulated lower conductive thin films having concentric pattern shapes were formed on an insulating substrate, and the lower conductive thin films were covered with an insulating film. Thereafter, a plurality of upper conductive thin films having a concentric pattern shape and insulated at a plane interval from each other are formed again on the insulating film, and then the upper conductive thin film is used as a mask to form the lower conductive thin film. After the etching is performed until the appearance of, a substance having a catalytic action or an oxidation-reduction action is deposited on at least one part of the conductive thin film.

[0013]

In the present invention, by arranging the comb-shaped modified electrodes concentrically around the sample introduction nozzle of the wall jet type cell, the electrodes and the arrangement of the electrodes are orthogonal to the flow direction of the carrier solvent throughout the cell. It has a structure to perform. For this reason, in addition to the excellent detection sensitivity of a normal wall-jet type electrochemical detector, the contact time between the electrode and the target substance is short, and the reaction product of the modification substance is not adjoined without passing through the modification coating. An electrochemical detector has been fabricated that combines the effect of high functionality with a comb-shaped micro-modified electrode, which enables efficient detection with a modified electrode. For this reason, this wall jet type electrochemical detector can obtain a detection function superior in terms of detection limit and analysis speed as compared with the conventional flow cell electrochemical detector.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. The present invention is not limited only to the following examples. (Embodiment 1) FIGS. 1 to 7 are sectional views showing steps of a configuration of a wall jet type electrochemical detector according to an embodiment of the present invention based on a manufacturing method thereof. In these figures, first, as shown in FIG.
A photoresist (MP1400-27, manufactured by Shipley) was applied to a thickness of 1.0 μm on a silicon wafer (manufactured by Osaka Titanium Co., Ltd.) 2 on which a silicon oxide film 1 of 0 μm was adhered. Next, the silicon wafer 2 coated with the photoresist was placed in an oven and baked at 80 ° C. for 30 minutes. After that, reduction projection exposure was performed for 0.3 second by a stepper (manufactured by Nikon: NSR1010G) using a reticle. Next, the exposed silicon wafer 2 is placed in a resist developing solution (MF-319, manufactured by Shipley Co., Ltd.) for 20 minutes.
Development was performed at 60 ° C. for 60 seconds, followed by washing and drying, and the reticle pattern was transferred to a resist to form a resist pattern 3 (FIG. 2).

Next, as shown in FIG. 3, the silicon wafer 2 on which the resist pattern 3 has been formed is mounted at a predetermined position in a sputtering apparatus (made by Anelva: SPF-332H), at a pressure of 1.3 Pa and a power of 50 W in argon. Sputtering of chrome for 10 seconds, without breaking vacuum
Subsequently, a chromium-platinum thin film 4 having a thickness of 100 nm was formed by sputtering platinum at a power of 70 W for 1 minute. Thereafter, the silicon wafer 2 is immersed in methyl ethyl ketone and subjected to ultrasonic treatment, and the resist pattern 3 other than the electrode forming portion is peeled off to form concentric multi-ring working electrodes 5 and 6 as shown in FIG. .

Next, as shown in FIG. 5, a thin silicon dioxide film 7 was deposited by sputtering on the silicon oxide film 1 on which the concentric multi-ring working electrodes 5 and 6 were formed. In this case, sputtering was performed at a power of 50 W for 10 minutes to form silicon dioxide 7 having a thickness of 300 nm. Next, a resist was applied again, exposed and developed, and a resist pattern 8 was formed on the silicon dioxide film 7 around the electrodes. Subsequently, it is placed in a reactive ion etching apparatus (DEM-451, manufactured by Anelva), and CF ₄ gas is supplied at a flow rate of 2
5SCCM, pressure: 0.25Pa, 1 under the conditions of 150W
The silicon dioxide film 7 was etched for 0 minutes to expose the concentric working electrodes 5 and 6 and their connection pads (not shown) (FIG. 6).

Next, as shown in FIG. 7, a lead wire (not shown) is connected to only one of the working electrodes, for example, the concentric multi-ring working electrode 5, and is immersed in an aqueous solution of glucose oxidase and pyrrole for electrolytic polymerization. Thus, a pyrrole polymer film 9 containing glucose oxidase was deposited on the concentric multi-ring working electrode 5. As a result, the surface of the concentric multi-ring working electrode 5 is covered (modified) with the pyrrole polymer film 9. The concentric multi-ring working electrode 5 and the concentric multi-ring working electrode 6 having the pyrrole polymer film 9 on the prepared surface have a shape in which ring-shaped electrodes are gathered concentrically at a planar interval. In this structure, every other ring assembly is meshed with each other so that different potentials can be applied between adjacent rings. Also, each of the manufactured concentric multi-ring working electrodes 5, 6
Are: electrode width: 1.0 μm, electrode interval: 1.0 μm, outermost electrode radius: 2.5 mm, number of electrodes: 625 each
It was a book. FIG. 8 shows a schematic diagram of an electrochemical detector having a concentric multi-ring modified electrode manufactured in this manner.

Next, this electrochemical detector was manufactured by PAS manufactured by BAS.
M-60 pump, LC-4C controller and RHEO
DYNE: 8125 injectors were combined to form a flow cell system. FIG. 9 shows a block diagram of this system. In the figure, 31 is a carrier container, 32 is a non-pulsating pump, 33 is a sample inlet, 34
Is a controller, 35 is a sump, 36 is a reference electrode,
37 is a counter electrode, 38 is a wall jet type electrochemical detector, and 39 is its concentric working electrode.

In such a configuration, a potential of 0.6 V is applied to the unmodified concentric working electrode with respect to the reference electrode 36, and a phosphate buffer solution (0. 1) in which glucose is dissolved at a concentration of 1 mmol / l. 1 mol / l, pH 6.8)
When 100 μl was injected at a flow rate of 1 ml / min, an oxidation current of hydrogen peroxide generated by the action of glucose oxidase was observed. After the sample injection,
It starts flowing in 4 seconds, shows a peak current value of 21 μA in 6 seconds,
It returned in 8 seconds. When a potential was applied to the concentric working electrode modified with the enzyme, a current began to flow 6 seconds after the sample was injected, a peak current of 50 nA was observed in 10 seconds, and it took 15 seconds for the current value to return to the original value. Cost me. Therefore, by using the unmodified concentric working electrode adjacent to the concentric working electrode modified by the enzyme, the sensitivity was improved and the time required for the measurement was shortened. Also, even in a glucose solution containing a large amount of impurities such as fructose, without being affected by the impurities,
Glucose could be detected selectively.

(Embodiment 2) FIGS. 10 to 17 are sectional views showing steps of another embodiment of a method of manufacturing a wall jet type electrochemical detector according to the present invention. Are given the same reference numerals. In the figure, first, as shown in FIG. 10, a silicon wafer (manufactured by Osaka Titanium Co., Ltd.) 2 having a silicon oxide film 1 having a thickness of 1.0 μm adhered to a surface thereof is sputtered (SPF-3 manufactured by Anelva).
32H), and chromium and platinum were sequentially deposited by sputtering. In this case, the pressure is 10 ⁻² Torr,
Sputtering was performed in an argon atmosphere under the conditions of chromium: 50 W, 10 seconds, platinum: 70 W, 1 minute to obtain a platinum-chromium thin film having a thickness of 100 nm. Thereafter, a photoresist (MP1400-27, manufactured by Shipley) was applied to the silicon wafer 2 to a thickness of 1 μm.
Next, a silicon wafer 2 coated with this photoresist
Was baked on a hot plate at 80 ° C. for 2 minutes. Then, use a mask aligner (PLA-
501), contact exposure was performed for 15 seconds. The exposed silicon wafer 2 was developed in a resist developer (manufactured by Shipley: MF319) at 20 ° C. for 60 seconds, washed with water and dried to transfer the mask pattern to the photoresist. Next, the silicon wafer 2 is mounted at a predetermined position in an ion milling apparatus (Millatron, manufactured by Commonwealth Scientific), and an argon gas pressure of 2 × 10 ⁻⁴ Torr is applied.
r, milling of the platinum-chromium thin film was performed for 2 minutes at an extraction voltage of 550 V, and thereafter, the photoresist was removed with an ashing device (manufactured by Tokyo Ohka: plasma asher) to form an electrode pattern of the lower multi-ring electrode 10 (FIG. 11).

Next, the silicon wafer 2 was put into a sputtering apparatus (manufactured by Anelva: SPF-332H) again, and the entire surface of the substrate of the silicon wafer 2 was covered with a silicon dioxide film 7 having a thickness of 100 nm (FIG. 12). After that, the silicon wafer 2 is attached to the sputtering device again,
Platinum sputter deposition was sequentially performed to form a 100 nm-thick platinum-chromium thin film. Thereafter, a photoresist (AZ140 manufactured by Shipley Co., Ltd.) is formed on the silicon wafer 2.
0-27) was applied to a thickness of 1.0 μm, alignment was performed, and the multi-ring electrode pattern was exposed in close contact. After the development, the platinum-chromium thin film is milled again, and the photoresist is removed by ashing to remove the upper multi-ring electrode 1.
One electrode pattern was formed (FIG. 13).

Next, the silicon wafer 2 was put into a sputtering apparatus (manufactured by Anelva: SPF-332H) again, and the entire surface of the substrate of the silicon wafer 2 was covered with a silicon dioxide film 7 having a thickness of 100 nm (FIG. 14). Next, a photoresist (manufactured by Shipley: AZ1) is formed on the silicon wafer 2.
400-27) is applied to a thickness of 1.0 μm, and only the multi-ring electrode portion (radius 2.5 mm) and the connection pad portion (not shown) meshed up and down are exposed and developed using a chrome mask, and the portion is exposed. (FIG. 15).

Next, this silicon wafer 2 is put into a reactive ion etching apparatus (DEM-451 manufactured by Anelva), and CF ₄ gas is supplied at a flow rate of 25 SCCM and a pressure of 0.2.
The silicon dioxide film 7 was etched for 5 minutes using the resist pattern 8 as a mask under the conditions of 5 Pa and 150 W to expose the upper multi-ring electrode 11 and the lower electrode 10. As a result, a concentric interlocking multi-ring electrode was obtained in which the two working electrodes divided vertically were extremely small (FIG. 16).

Next, a lead wire (not shown) is connected to only one of the working electrodes, for example, only the lower multi-ring electrode 10, immersed in an aqueous solution of glucose oxidase and pyrrole, and subjected to electrolytic polymerization to thereby form a pyrrole polymer film containing glucose oxidase. Coated by depositing 9,
Decorated (FIG. 17). The shape of the manufactured concentric multi-ring modified electrodes 11 and 12 is determined by the width of each ring electrode:
2.0 μm, step between upper and lower multi-ring electrodes: 0.3
μm, radius of outermost electrode: 2.5 mm, number of combs: 625 each. FIG. 18 is a schematic view of the electrode portion of the electrochemical detector thus manufactured.

The electrochemical detector thus manufactured was incorporated into the same flow cell system as in Example 1, and a potential of 0.6 V was applied to the working electrode which was not modified with respect to the reference electrode, and glucose was changed to 1 mmol / mol. phosphate buffer (0.1 mol / l, pH 6.8) 10
When 0 μl was injected at a flow rate of 1 ml / min,
The oxidation current of hydrogen peroxide generated by the action of glucose oxidase was observed. The current started to flow at 4 seconds after the sample injection, showed a peak current value of 30 μA at 6 seconds, and returned to the original value at 8 seconds. When a potential was applied to the electrode modified with the enzyme, a current began to flow 6 seconds after the sample was injected, a peak current of 75 nA was observed in 10 seconds, and it took 15 seconds for the current value to return to the original value. Therefore, by using the unmodified electrode adjacent to the electrode modified by the enzyme, the sensitivity and the response speed were improved.

(Embodiments 3 to 5) In the same manner as in Embodiment 1, the width of each electrode: 2 μm, the interval between electrodes: 2 μm
(Example 3), width of each electrode: 5 μm, electrode interval: 5 μm
(Example 4), width of each electrode: 10 μm, electrode interval: 10
A concentric wall jet type electrochemical detector modified with a glucose oxidase of μm (Example 5) was produced.

Using these electrodes, the potential of the electrode which was not modified with respect to the reference electrode was set to 0.6 V, and the response current measured in the same manner as in Example 1 and the concentric multi-ring modification The relationship with the dimensions of the electrodes is shown in Table 1 below together with the results measured using the electrodes of Example 1.

[0028]

[Table 1]

(Embodiments 6 to 8) In the same manner as in Embodiment 1, each electrode is fixed at an electrode width of 1 μm, and the electrode interval is 2 μm (Example 6), and the electrode interval is 5 μm (Example 7). ), A concentric wall jet type electrochemical detector having an electrode spacing of 10 μm (Example 8) was produced.

The response current measured by the same method as in Example 1 with the potential of the electrode not modified using these electrodes set to 0.6 V with respect to the reference electrode and the concentric multi-ring modification Table 2 below shows the relationship between the electrodes and the electrode spacing together with the results measured using the electrodes of Example 1.

[0031]

[Table 2]

(Embodiment 9) In the same manner as in Embodiment 2, the radius of the center lower electrode and the width of the upper electrode adjacent thereto are set to 50 μm, and the width of a pair of adjacent upper and lower electrodes is made equal. Meanwhile, concentric wall-jet type electric motors modified with glucose oxidase such that the width of the electrodes gradually decreases by 1 μm each at 49 μm and 48 μm as the distance from the center increases, and the width of each of the upper and lower electrodes becomes 1 μm at the outermost circumference. A chemical detector was made.

Using this electrode, the potential of the upper electrode, which was not modified with respect to the reference electrode, was set to 0.6 V, and the potential was measured in the same manner as in Example 2. The current started to flow, showed a peak current value of 11 μA at 6 seconds, and returned to the original value at 8 seconds.

In the above-described embodiment, a silicon wafer with an oxide film is used as the substrate having an insulating surface or the entire surface. In addition, a quartz plate, an aluminum oxide substrate, a glass substrate, a plastic substrate, or the like may be used. Can be mentioned. In addition, gold, platinum, silver,
Examples include chromium, titanium, and stainless steel.
Semiconductors for electrodes include p-type and n-type silicon, p-type and n-type germanium, cadmium sulfide, titanium dioxide, zinc oxide, gallium phosphide, gallium arsenide,
Indium phosphorus, cadmium selenium, cadmium tellurium, molybdenum dioxide, tungsten selenide, copper dioxide, tin oxide, indium oxide, indium tin oxide, and the like can be given. In addition, conductive carbon can be used as the semimetal. Examples of the insulating film include silicon oxide, silicon dioxide, silicon nitride, silicon resin, polyimide and its derivatives, epoxy resin, and thermosetting polymer.

The microelectrode is manufactured by a combination of lithography techniques such as a thin film forming method, a resist pattern forming method, and an etching method. Also, as a method of forming a thin film,
Examples include a vapor deposition method, a sputtering method, a CVD method, and a coating method. Furthermore, as a resist pattern forming method,
Photolithography, electron beam lithography, X-ray lithography and the like can be used. In addition, as a pattern forming method, first, a thin film is formed on the entire surface of the substrate, a resist pattern is formed thereon, and using this as a mask, an etching method or a resist pattern is formed by etching a lower thin film, and then a thin film is formed thereon. By depositing and removing the resist, a lift-off method or the like for forming a thin film pattern only on a portion not covered with the resist can be used.

Further, examples of the shape of the electrode include not only concentric circles but also polygons such as concentric squares and hexagons and ellipses having the same focal point.

On the other hand, as a method for modifying at least one of the working electrodes with a substance having a catalytic action or an oxidation-reduction action, a functional group which causes electrolytic polymerization such as a vinyl group is introduced into the substance, and this is converted into tetraethyl perchlorate. Dissolved in a suitable solvent such as acetonitrile with a supporting electrolyte such as
After immersing the electrode cell and a counter electrode of platinum or the like in this, a voltage may be applied to the working electrode to cause electrolytic polymerization on the electrode. Further, a method of mixing a redox substance having a catalytic action with an electropolymerizable substance such as pyrrole and subjecting the resultant to electrolytic polymerization to precipitate a plurality of polymer films on the electrode can also be mentioned.

[0038]

As described above, the electrochemical detector incorporating the concentric multi-ring modified electrode according to the present invention has a highly sensitive detection for a flow cell by forming the micro comb-shaped modified electrode in a concentric shape. In the wall-jet type electrode cell, which is a vessel, the micro-comb-shaped modified electrode functions efficiently. For this reason, an electrochemical detector for a flow cell which has higher sensitivity than an electrode in which an electrode for detecting a target substance is coated with a modifying substance like a conventional plate-like modified electrode can be realized. Furthermore, the time required for measuring one sample was short, and measurement of many samples was possible in a short time. In addition, since it is manufactured by using the lithography technique, a large number of measurement cells having at least one set of concentric electrodes of any size, shape, and distance between electrodes can be obtained at low cost. Further, by selecting a material that modifies the electrode, it is possible to respond to only a specific substance or to change the response potential so that detection is performed at a potential different from the response potential of the interfering substance.
In addition, the electrochemical reaction can be switched by changing the potential of the modified electrode. Therefore, an extremely excellent effect such as a great use value as a flow cell or an electrochemical detector for liquid phase chromatography can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a process for explaining one embodiment of a method for manufacturing an electrochemical detector according to the present invention.

FIG. 2 is a cross-sectional view illustrating steps of an embodiment of a method for manufacturing an electrochemical detector according to the present invention.

FIG. 3 is a cross-sectional view illustrating steps of an embodiment of a method for manufacturing an electrochemical detector according to the present invention.

FIG. 4 is a cross-sectional view of a process for explaining one embodiment of a method for manufacturing an electrochemical detector according to the present invention.

FIG. 5 is a cross-sectional view illustrating steps of an embodiment of a method for manufacturing an electrochemical detector according to the present invention.

FIG. 6 is a cross-sectional view illustrating steps of an embodiment of a method for manufacturing an electrochemical detector according to the present invention.

FIG. 7 is a cross-sectional view of a step for explaining one embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 8 is a perspective view showing a configuration of an electrochemical detector according to an embodiment of the present invention.

FIG. 9 is a diagram showing a block diagram of a flow cell system used for measurement.

FIG. 10 is a cross-sectional view of a process for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 11 is a sectional view of a step for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 12 is a cross-sectional view of a step for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 13 is a sectional view of a step for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 14 is a cross-sectional view showing a step of another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 15 is a cross-sectional view of a step for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 16 is a sectional view of a step for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 17 is a sectional view of a step for explaining another embodiment of the method for manufacturing an electrochemical detector according to the present invention.

FIG. 18 is a perspective view showing a configuration of another embodiment of the electrochemical detector according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon oxide film 2 Silicon wafer 3 Resist pattern 4 Chromium-platinum electrode 5 Concentric multi-ring working electrode 6 Concentric multi-ring working electrode 7 Silicon dioxide film 8 Resist pattern 9 Pyrrole polymer film 10 Lower multi-ring electrode 11 Upper multi-ring electrode

Continuation of front page (56) References JP-A-5-2007 (JP, A) JP-A-5-60723 (JP, A) JP-A-2-99850 (JP, A) JP-A-2-87056 (JP) JP-A-1-282457 (JP, A) JP-A-1-263551 (JP, A) JP-A-64-32160 (JP, A) JP-A-62-235557 (JP, A) 63-218850 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 27/30 G01N 27/28 321 G01N 27/327 G01N 30/64

Claims (3)

(57) [Claims] 1. A wall-jet electrochemical device comprising at least two concentric electrodes, wherein at least one of the concentric electrodes is coated with a substance having a catalytic action or a redox action. Detector. 2. The method according to claim 1, comprising a plurality of concentric electrodes formed on an insulating substrate, wherein each of said concentric electrodes is a minute planar gap and / or a minute step formed by a three-dimensional step via an insulating layer. A wall jet type electrochemical detector, wherein at least a part of each concentric electrode surface is exposed by being separated by an interval. 3. A first metal or semi-metal or semiconductor having a concentric pattern shape on a surface or an entire surface of an insulating substrate, or a plurality of metals, semi-metals or semiconductors insulated from each other by a planar gap.
After the first conductive thin film is formed, and the first conductive thin film is covered with an insulating film, a single or a plurality of second conductive thin films having a concentric pattern shape and insulated by a planar gap are provided. Forming again on the insulating film, and then forming the second
Using the conductive thin film pattern as a mask, etching the insulating film until the first conductive thin film appears, and then adding a catalyst to at least one of the first conductive thin film and the second conductive thin film. A method for producing a wall jet type electrochemical detector, wherein a substance having an action or an oxidation-reduction action is deposited.