JP2005207860A - Method for manufacturing chip for blood analyzer - Google Patents

Abstract

[Purpose] The substrate and the cover plate are made of a resin material, blood cells and proteins are difficult to adhere from the blood collection part to the analysis part, and the blood or serum transfer ability of the moving part is excellent, and the reliability and economy are high. Provided is a method for manufacturing a rich blood analysis device chip.
[Configuration] Channel wall surface treatment of a channel structure composed of a resin substrate formed with a groove to be a series of blood channels from the collection part to the moving part and a resin lid plate covering the groove Injecting a solution of a substance having photocatalytic activity into the flow path from the collection part to the moving part with a syringe pump, depositing the substance on the wall surface of the flow path, and heat-treating the photocatalytically active film on the wall surface of the flow path Next, a solution of a water-repellent substance is injected with a syringe pump into the flow path from the collection part to the analysis part, and the solution is attached to the wall surface of the flow path and heat-treated. A water repellent film is formed.
[Selection] Figure 1

Description

  The present invention separates red blood cells, white blood cells, lymphocytes, platelets, blood coagulation factors, and the like from blood collected from a human body, and measures the pH value, oxygen concentration, carbon dioxide concentration, etc. of the resulting serum to obtain blood The present invention relates to a method for manufacturing a chip used in a blood analyzer that analyzes the state of the blood.

One of the devices for diagnosing human health and diseases is a blood analyzer. This is because several milliliters of blood is collected from the human body, and serum obtained by separating red blood cells, white blood cells, lymphocytes, platelets, blood coagulation factors, etc. using a centrifuge is dispensed into a number of test tubes. Then, move these test tubes in a line, measure the pH, each concentration of oxygen, carbon dioxide, etc. with a chemical sensor, and add reagents such as enzymes to the tester's serum. Spectroscopy and absorption spectroscopy of the luminescence reaction with the substrate. The data thus obtained is processed by a computer and used to judge a person's health condition and disease.
Conventionally, this type of blood analyzer is installed in a large-scale medical institution such as a hospital, is large, and its operation is often limited to those who have specialized qualifications. However, in recent years, instead of such a large blood analyzer, a small and simple blood analysis method and blood analyzer aimed at performing blood analysis by one's own hands in each home have been proposed. Yes.

As a specific example, for example, Patent Document 1 discloses a blood analyzer having the following configuration. The outline of this blood analyzer will be described with reference to FIGS. FIG. 3 is a plan sectional view showing the configuration of the blood analyzer chip 100 of this device, and FIG. 4 is a model plan sectional view showing the configuration of one flow path of the blood analyzer chip 100. Both are shown with the top lid removed.
The blood analyzer chip 100 includes a collection unit 1 for collecting blood, a filtration unit 2 for filtering red blood cells and white blood cells from the collected blood to obtain plasma, and centrifugal force from the obtained plasma. Separation unit 3 for separating coagulation molecules such as proteins to obtain serum, analysis unit 4 for analyzing the properties of the obtained serum and substances in the serum, and electrophoresis of blood or blood components in the flow path The moving part 5 that is moved by force is provided as a series of flow paths, and the separation part 3 is a common part, and the subsequent analysis parts 4 and moving parts 5 are provided as a branch flow path. Such a flow path is formed by integrating a substrate on which a groove for the flow path is formed and a cover plate that is bonded to the groove side surface of the substrate in order to use the groove as a flow path. For this integration, methods such as adhesion, bonding, and pressure bonding are used. 3 and 4 correspond to a state in which the substrate is viewed from the groove forming surface side.

  The blood to be analyzed is collected by inserting a hollow needle 11 such as an injection needle at the tip of the collection unit 1 into the blood vessel, and the red blood cells, white blood cells, Lymphocytes and platelets are sequentially filtered to form plasma, which is sent to the U-shaped separation unit 3. In this state, the blood analysis device chip 100 is mounted on the centrifuge and accelerated toward the U-shaped bottom, and the coagulation molecules in the plasma are separated and removed from the U-shaped bottom. Serum is obtained. This serum is sent to a plurality of branched analysis units 4 and sensors (not shown) arranged in the respective analysis units 4 make it possible to adjust the pH value, oxygen, oxygen dioxide, sodium, potassium, calcium, glucose, lactic acid, Etc. are measured. In order to move the serum obtained in the separation unit 3 to the analysis unit 4, an electroosmotic flow due to an electrophoretic force generated between the electrodes by the voltage applied to the electrodes 51 and 52 of the movement unit 5 is used. The

Conventionally, glass substrates such as quartz and silicon wafers have often been used as the material of the substrate used in such a blood analysis device chip 100, but these are generally expensive and are not suitable for mass production. It is unsuitable. For this reason, resin materials that can be manufactured at low cost have come to be used.
However, when a resin material is used for the substrate, there is a problem in that the ability of the pumping action in the moving unit 5 utilizing electroosmotic flow is low because the surface zeta potential is low in terms of material properties. Further, in the flow path other than the moving part 5, proteins or blood cells in blood are likely to adhere to the wall surface of the flow path, and surface treatment is required to prevent it.
In order to cope with these problems, in Patent Document 1, for example, when the substrate is a resin material PET (polyethylene terephthalate), the wall surface of the flow path of the moving unit 5 is covered with a silicon oxide film 53, and the others. The wall surface of the flow path is covered with a coating film 7 of organic molecules having biocompatibility.
JP 2002-267677 A

In Patent Document 1, as a means for increasing the zeta potential on the surface of the resin material, the flow path is blocked at an intermediate position between the analysis unit 4 and the movement unit 5, and HMDS (hexa Methyl disilazane), and then the temperature is raised to evaporate the solvent to coat the wall surface of the flow path of the moving part 5 with the silicon oxide film 53, and at least a molecular gas containing silicon as a constituent element and at least A silicon oxide film 53 is coated on the wall surface of the flow path of the moving section 5 by plasma chemical vapor deposition in which a gas of molecules containing oxygen as a constituent element is introduced into the flow path of the moving section 5 to generate plasma. A method is disclosed.
In this method, the zeta potential of the wall surface of the flow channel of the moving unit 5 can be increased, but it is necessary to open a hole in the cover plate in the middle of the flow channel to block the flow channel on the analysis unit 4 side. The problem is that the process of forming the silicon oxide film 53 is complicated.

On the other hand, as a method for imparting biocompatibility to the wall surface of the flow path to the analysis unit 4, a solution containing MPC polymer (2-methacryloyloxyethylphorylcholine) or polymer micelles is maintained in a reduced pressure state to the analysis unit 4 Is then injected into the flow path by the suction force, and then the solvent is volatilized to cover the wall surface of the flow path as a coating film 7 with MPC polymer or polymer micelle. Although the biocompatibility of the wall surface of the flow path is improved by this method, it is necessary to block the flow path on the moving unit 5 side, and the inside of the flow path must be in a reduced pressure state. The problem is that the method is complicated and time-consuming.
An object of the present invention is to solve the above problems, the substrate and the cover plate are made of a resin material, blood cells and proteins are difficult to adhere from the collection part to the analysis part, and the ability to transfer blood or serum of the moving part And a method for manufacturing a chip for a blood analyzer excellent in reliability and economy.

  The invention of claim 1 includes a first flow path for taking in blood, a second flow path for filtering blood to obtain plasma, and separating coagulated molecules from the obtained plasma by centrifugal force. A third channel for obtaining serum, a fourth channel for analyzing the properties of the obtained serum and substances in the serum, and electrophoresis of blood or blood components in each of the channels The fifth flow channel for moving by force is arranged in communication with each other in order, and the treatment for suppressing adhesion of blood cells and proteins in the blood to the wall surfaces of the first flow channel to the fourth flow channel And the wall surface of the fifth flow path is subjected to a treatment for increasing the zeta potential, and is a resin blood analysis device manufacturing method, wherein the first flow path from the first flow path is A step of forming a thin film of a substance having photocatalytic activity on the wall surface of the channel 5, and subsequently the fourth channel to the fourth channel And a step of the wall forming a water-repellent film composed mainly of fluorocarbon resin.

As described in the section “Best Mode for Carrying Out the Invention”, the above two steps are steps that can be performed with simple equipment and simple operations. A thin film of a substance having photocatalytic activity is formed on the wall surface of the path, and a water-repellent film mainly composed of a fluororesin is formed on the wall surfaces of the first to fourth channels.
A substance having photocatalytic activity has a property similar to that of an n-type semiconductor and thus has a high zeta potential. “Photocatalytic activity” is a phenomenon in which various effects are manifested by strong oxidizing power and reducing power caused by ultraviolet irradiation. Substances having this property include titanium oxide (TiO ₂ ), zinc oxide ( ZnO), zinc sulfide (ZnS), and the like. All of these substances can be applied to blood analysis device chips, but chemical stability of the substance itself, prevention of reaction with blood components, and prevention of blood contamination due to elution into blood, etc. Judging from such viewpoints, titanium oxide and a composite mainly composed of titanium oxide are most suitable for the object of the present invention. Examples of the additive to titanium oxide include tungsten trioxide (WO ₃ ) and silicon oxide (SiO ₂ ) as preferable substances.

The water-repellent film mainly composed of fluororesin has a very high water repellency with a contact angle with water of around 110 °, so it suppresses the adhesion of blood cells and proteins in the blood to the minimum. It becomes possible.
The invention of claim 2 uses titanium oxide and a composite thereof as the substance having photocatalytic activity in the invention of claim 1.
As described above, titanium oxide and its composites have excellent photocatalytic activity and are excellent in chemical stability so that they do not contaminate blood or blood components and are most suitable for the purpose of the present invention. ing.

  According to the first aspect of the present invention, a step of forming a thin film of a substance having photocatalytic activity on the wall surface of the first flow path from the first flow path, followed by the fourth flow from the first flow path. Forming a water-repellent film mainly composed of a fluororesin on the wall surface of the road, and these two steps are described in the section “Best Mode for Carrying Out the Invention” It is a process that can be carried out with simple equipment and simple work. By these two processes, a thin film of a substance having photocatalytic activity is formed on the wall surface of the fifth flow path, and the fourth flow from the first flow path. A water-repellent film mainly composed of a fluorine-based resin is formed on the wall surface of the road. A substance having photocatalytic activity has a high zeta potential because it has properties similar to those of an n-type semiconductor. The water-repellent film mainly composed of a fluorine-based resin has a surface state in which blood cells and proteins are hardly attached due to its excellent water-repellent function. Therefore, according to the present invention, the substrate and the cover plate are made of a resin material, and it is difficult for blood cells and proteins to adhere from the first flow channel as the collection unit to the fourth flow channel as the analysis unit, and the moving unit. It is possible to provide a method for manufacturing a chip for a blood analyzer that is excellent in the ability to transport blood or serum in the fifth flow path, and that is highly reliable and economical.

In the invention of claim 2, titanium oxide and a composite thereof are used as a substance having photocatalytic activity, but titanium oxide and a composite thereof have excellent photocatalytic activity and are excellent in chemical stability. Does not contaminate blood or blood components. Therefore, according to the present invention, a highly reliable method for manufacturing a chip for a blood analyzer can be provided.
Here, taking the titanium oxide as an example, the principle of the photocatalytic activity reaction and the effect thereof will be described. When titanium oxide, which is an n-type semiconductor, is irradiated with ultraviolet rays having a wavelength of 387 nm or less corresponding to the band gap, electrons are photoexcited from the valence band to the conduction band, and holes are generated in the valence band. These electrons and holes respectively move to the surface of titanium oxide and react with oxygen and organic substances adsorbed on the surface. At this time, the photogenerated holes are at the energy level of the valence band (+3 V with respect to the hydrogen standard electrode) and have a strong oxidizing power, so almost all organic substances adsorbed on the surface are oxidized and decomposed. Is done. Furthermore, active oxygen species (OH radicals, hydrogen peroxide, etc.) having strong oxidizing power are generated from oxygen and water, contributing to the oxidative decomposition of organic matter. By this series of photocatalytic activity reactions, super hydrophilicity is imparted to the surface of titanium oxide. Due to this organic decomposability and super hydrophilicity, the surface of titanium oxide irradiated with ultraviolet rays exhibits properties such as antifouling properties, antifogging properties, antibacterial properties, sterilizing properties, cleanability, and easy cleaning properties. come.

  As is clear from the above explanation, the main purpose of forming a film of titanium oxide and its composite on the wall surface of the fifth flow path which is a moving part is to increase the zeta potential of the surface, but at the same time, photocatalytic activity Various effects associated with the reaction improve the characteristics even in functions other than the transfer function, such as maintaining cleanliness of the surface, preventing contamination to blood components, and increasing the possibility of repeated use. It demonstrates the effect of letting

The best mode for carrying out the present invention will be described with reference to examples.
In addition, the same code | symbol is attached | subjected to the part of the same function as a prior art.
FIG. 1 is a process diagram showing an embodiment of a method for manufacturing a blood analyzer according to the present invention, and FIG. 2 shows the configuration of one flow path of a blood analyzer chip 100a of the blood analyzer manufactured by this manufacturing method. FIG. 2 is a model plan sectional view showing a state in which the upper cover plate is removed.
The feature of this embodiment is that, as the material of the substrate and the cover plate constituting the chip, a thermoplastic resin that is low in material cost and easy to mass-produce by injection molding or the like is employed, and sampling A film of a substance having photocatalytic activity (hereinafter referred to as a photocatalytic active film) 8 made of titanium or a composite thereof is formed on the entire wall surface of the flow path from the section 1 to the moving section 5, and then, from the collection section 1 side to the analysis section The water-repellent film 7a mainly composed of a fluorine-based resin is formed on the wall surfaces of the flow paths up to four.

Hereinafter, the embodiment will be described in more detail with reference to FIGS. 1 and 2.
The process in which the substrate on which the channel for the channel from the sampling unit 1 to the moving unit 5 is formed and the lid plate covering the channel are integrated by adhesion, pressure bonding, etc. to form the channel structure is shown in FIG. Although omitted in 1, PET (polyethylene terephthalate) was used as a substrate material, and a substrate having a channel groove having a channel configuration shown in FIG. 2 was manufactured by injection molding. FIG. 2 shows only one flow path as a model, and the actual flow path includes a plurality of analysis units 4 and moving units 5 as in FIG. The width of the flow path of each part is 30 μm in the narrow part, and 300 to 500 μm in the wide part of the filtration part 2 and the analysis part 4. The depth is in the range of 50 to 200 μm. The width of the slit 21 of the filtration unit 2 decreases from a few ten μm to a few μm from the upstream side toward the downstream side. The same PET as the substrate material is used for the lid plate material, and thermocompression bonding is adopted for the integration of the substrate and the lid plate. However, the integration can also be performed by solvent bonding.

From the collecting part 1 of the flow path structure formed by integrating the substrate on which the groove for the flow path from the collecting part 1 to the moving part 5 is formed and the lid plate covering the groove by bonding or pressure bonding. Then, a separately prepared titanium oxide solution (photocatalyst solution in FIG. 1) is injected into the entire flow path from the sampling unit 1 to the moving unit 5 by a syringe pump, and left to stand for 30 minutes to flow titanium oxide crystal particles. After being deposited on the wall surface of the road, the solution is discharged from the flow path and heat treated at 80 ° C. for 30 minutes to collect a film of a substance having photocatalytic activity made of titanium oxide (hereinafter referred to as a photocatalytic active film) 8. It was formed on the entire wall surface of the flow path from 1 to the moving part 5. The injected titanium oxide solution is a solution containing alcohol / ketone containing 10% by weight of titanium oxide crystal particles having a crystallite diameter of 5 to 30 nm as a solvent.
There are two methods for forming a photocatalytically active film such as titanium oxide, including a physical film-forming method such as vapor deposition and sputtering, and a method of applying a heat treatment after applying a solution. In the case of forming a film, the latter method must be used, and after the solution is injected by a syringe pump, the solution is left standing for a while and the solution is discharged. The temperature of the heat treatment can be selected from the range up to 500 ° C. including room temperature drying, but considering the heat resistance of the substrate material, 80 to 150 ° C. is preferable, and 80 ° C. in the examples. The thickness of the photocatalytic active film 8 varies greatly depending on the purpose of use, but in the case of the present invention, it is preferably 0.08 to 0.5 μm. If it is less than 0.08 μm, the electrodes 51 and 52 may be peeled off when a voltage is applied to the moving part 5, and it is difficult to produce a film having a thickness exceeding 0.5 μm by the injection method.

Next, the fluororesin solution (water repellent substance solution in FIG. 1) prepared separately by a syringe pump from the collection unit 1 side is moved down from the collection unit 1 to the separation unit 3, and the moving unit 5 is up. In this way, the sample is injected up to the upper part of the analysis unit 4 (the right end of the water-repellent film forming range shown in FIG. 2) and left to stand for 1 minute, and then the solution is discharged from the injection side and heat-treated at 120 ° C. for 1 hour. Then, a water repellent film 7a mainly composed of a fluorine-based resin was formed on the wall surface of the flow path from the collection unit 1 to the analysis unit 4. The injected solution was prepared by applying a water-repellent coating agent containing fluorine resin (Asahi Glass Co., Ltd., trade name: CYTOP CTL-809MD) and a low-boiling fluorine compound dispersion solvent (Asahi Glass Co., Ltd., trade name: CT-SOLV1820) diluted to 0.5% by weight. By diluting, the viscosity is lowered to a viscosity that is easy to inject.
Although the analysis unit 4 and the movement unit 5 shown in FIG. 2 are one set, the blood analysis device chip 100a usually includes a plurality of sets of the analysis unit 4 and the movement unit 5. In order to allow the water-repellent substance solution to reach the upper part of all the analysis units 4 by the method of injecting the water-repellent substance solution, the boundary positions of the analysis unit 4 and the moving unit 5 are aligned at the same level.

The heat treatment conditions of the fluororesin solution adhering to the wall surface of the flow path are suitably from 80 to 200 ° C. and within the range of 0.5 to 3 hours, and in the examples, 120 ° C. and 1 hour. The thickness of the water repellent film 7a varies depending on the purpose of use, but is usually 0.1 to 1 μm. In the case of this invention, the effect is sufficiently exhibited at around 0.3 μm. If the thickness is 0.1 μm or less, sufficient water repellency cannot be obtained due to the influence of the base, and if it is 1 μm or more, the film is liable to crack, and troubles such as falling off are likely to occur.
The blood analyzer chip 100a is completed by the above-described steps. On the wall surface of the flow path from the collection unit 1 to the analysis unit 4, the water repellent film 7 a covers the photocatalytic active film 8, and only the wall surface of the flow path of the moving unit 5 is exposed to the photocatalytic active film 8. It is. As a result, the flow path from the collection unit 1 to the analysis unit 4 covered with the water-repellent film 7a is in a wall surface state to which blood cells or the like are difficult to adhere, and the flow path of the moving unit 5 covered with the photocatalytic active film 8 Has a high zeta potential wall surface and has an excellent blood transfer capability. For this reason, the moving part 5 of the blood analyzer chip 100a manufactured according to this embodiment has a small and simple shape as shown in FIG.

As is clear from the above description, the photocatalytically active film 8 and the water repellent film 7a may be formed by using a syringe pump and an electric furnace or a thermostatic chamber that can be heated to about 150 ° C. for heat treatment. The method for producing a chip for a blood analysis device according to the method is excellent in economy.
The completed blood analysis device chip 100a was cut and the cross section was observed with a scanning electron microscope to measure the thickness of the photocatalytic active film 8 and the water repellent film 7a. The thickness of the photocatalytic active film 8 was 0.09 μm. The thickness of the water repellent film 7a was 0.15 μm.
Moreover, when blood was injected into the completed blood analysis device chip 100a and a predetermined voltage was applied between the electrodes 51 and 52 of the moving part 5, the blood could be moved as planned.
Furthermore, a fluororesin water-repellent film was formed on PET under the same process conditions as described above, and the adhesion density of red blood cells was compared with that of PET itself. As a result, the surface of PET itself was around 600 per square mm. In the case where the water-repellent film was formed, the number was dramatically reduced to 10 or less per square mm, and the remarkable effect of the water-repellent film was confirmed.

In the above embodiment, PET is used as the substrate material, but other thermoplastic resin materials such as polyethylene, polyurethane, methacrylic resin, polybutylene terephthalate, polyimide, polycarbonate, polysulfone, etc. can be used. It was confirmed.
The fluororesin as a material for the water-repellent film 7a is not particularly limited. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoro, and the like. Various fluororesins such as propylene copolymer (FEP), tetrafluoroethylene / ethylene copolymer (FTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and the like can be used. Especially, what has perfluoro groups, such as PTFE, PFA, and FEP, is preferable.

In addition, the fluorine resin solution preferably contains a primer component in addition to the fluorine resin. An example of the primer component is a silane coupling agent. By adding the primer component, for example, the reaction between the silanol group of the silane coupling agent and the resin surface proceeds, and a fluororesin thin film having excellent adhesion can be formed.
Although it does not specifically limit as a silane coupling agent, For example, at least 1 type of alkoxy group selected from the group which consists of a methoxy group and an ethoxy group, an amino group, a vinyl group, an acrylic group, a methacryl group, an epoxy group, a mercapto group And a silane coupling agent having at least one reactive functional group selected from the group consisting of a halogen group and an isocyanate group.
As a solution containing the above fluororesin as a main component, a commercially available water repellent coating agent containing a fluororesin can be used. In the examples, as described above, trade names of Asahi Glass Co., Ltd. Cytop was used.

Process drawing which shows the Example of the manufacturing method of the blood analyzer by this invention Model plane cross section showing the configuration of the flow path of the blood analysis device chip 100a manufactured by the method of manufacturing a blood analysis device according to the present invention Plan sectional view showing the configuration of a blood analyzer chip 100 as an example of a blood analyzer according to the prior art Model plane cross section showing the configuration of the flow path of the conventional blood analysis device chip 100

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sampling part 11 Hollow needle 2 Filtration part 21 Slit 3 Separation part 4 Analysis part 41 Lead wire 5 Pump part 51, 52 Electrode 53 Silicon oxide film 6 Control part 7 Coating film
7a Water repellent film 8 Photocatalytically active film
100, 100a Blood analyzer chip

Claims (2)

A first flow path for taking blood, a second flow path for filtering the blood to obtain plasma, and a second flow path for separating coagulation molecules from the obtained plasma by centrifugal force to obtain serum. 3 channels, a fourth channel for analyzing the properties of the obtained serum and substances in the serum, and a second channel for moving blood or blood components in each channel by electrophoretic force. 5 are arranged in communication with each other in order, and the wall surfaces of the first to fourth channels are subjected to a treatment for suppressing adhesion of blood cells and proteins in the blood, and The wall surface of the flow path is a method for producing a resin blood analysis device chip that has been subjected to a treatment for increasing the zeta potential,
Forming a thin film of a substance having photocatalytic activity from the first channel to the wall surface of the fifth channel;
Subsequently, a step of forming a water-repellent film mainly composed of a fluororesin on the wall surface of the fourth channel from the first channel,
A method for manufacturing a chip for a blood analyzer characterized by the above. As the substance having photocatalytic activity, titanium oxide and a composite thereof are used.
The method for manufacturing a chip for a blood analyzer according to claim 1.

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