JP5902426B2 - Liquid feeding device and liquid feeding method - Google Patents

Description

  The present invention relates to a liquid feeding apparatus and a liquid feeding method capable of controlling the flow of a liquid, and further relates to a micro analysis chip and an analysis apparatus for performing a trace chemical analysis.

In the medical field, biochemical field, etc., immunoassay methods for measuring various components that are indicators of health conditions and diseases present in specimens such as blood and urine are known as important analysis and measurement methods. ing. However, a general measurement method requires complicated work such as pretreatment to make a sample ready for measurement and use of multiple devices, and the reaction at each stage of measurement requires time. Takes more than a day for analysis.
Therefore, in order to be able to carry out this analysis easily and in a short time, and in order to promote the implementation of clinical tests (so-called POCT) in the vicinity of patients such as hospital bedsides and homes, simple operations can be used. There is a demand for a small analyzer that can perform quick analysis.

Against this background, recently, micro-analysis chips that form micro-order flow paths on a substrate and perform various reactions in the flow paths have been developed and put into practical use.
The microanalysis chip can perform analysis with a simple operation using a small amount of test solution, and can reduce the amount of necessary samples, shorten the analysis time, and reduce the size of the device. In order to perform washing and reaction, a function to sequentially feed a very small amount of liquid and a function to stop the liquid at the time of detection are required, and the liquid supplied to the flow path is moved using pneumatic action force. A so-called micropump is incorporated (see, for example, Patent Document 1).
A micro analysis chip incorporating this micro pump can deliver a plurality of liquids and can be stopped at any timing. However, since the configuration is complicated, there are large peripheral devices for controlling the chip. Tend to be.
For this reason, a micro-analysis chip has been developed that does not use a micropump, but transports liquid using a capillary phenomenon or an absorber that occurs between a flow path and a liquid in the flow path (for example, see Patent Document 2). .

JP 2008-128906 A JP 2001-88096 A

The micro analysis chip using the capillary force is generally based on the micro flow channel structure shown in FIG.
In FIG. 10, reference numeral 106 denotes a first substrate, 105 denotes a second substrate, 103 denotes a flow path, 101 denotes a liquid introduction portion, and 102 denotes a liquid discharge portion. When the liquid is dropped onto the introduction part 101, the liquid moves through the flow path 103 by capillary force and moves to the discharge part 102 . Therefore, the liquid can be moved from the introduction unit 101 side to the discharge unit 102 side without requiring an external force such as a pump. However, in this method, when a liquid having an amount smaller than the flow path volume is used, it is difficult to feed the liquid to a predetermined position or to stop at a specific place.

For this reason, as described in Utility Model Registration No. 3142126, an amount of liquid smaller than the volume of the flow path is manually injected into the flow path 103, and oil is additionally injected to feed the liquid to a predetermined location. However, since it uses capillary action, it cannot be precisely controlled.
Furthermore, when a plurality of flow paths are connected, the amount of liquid is so large that when the liquid is sent to another flow path, the detection value decreases or the other liquid decreases due to dilution by mixing with another liquid. This is a factor that affects the detected value, such as reaction inhibition by components contained in.
In addition, since the micro analysis chip uses a very small amount of liquid, capacity fluctuation and concentration occur due to evaporation due to the external environment and time, and measurement error becomes a problem.
The present invention eliminates such inconveniences, has a simple structure and can be manually controlled, a liquid feeding apparatus and a liquid feeding method, a microanalysis chip using the liquid feeding apparatus, and a microanalysis chip. It aims at providing the used analytical device.

In order to achieve the above object, the present invention provides a liquid comprising at least a first liquid that is a target liquid to be fed and a second liquid that is a driving liquid that can be separated by interfacial tension in the flow path. in liquid delivery device for moving by the action of interfacial tension at the interface formed between the first liquid and the second liquid located in the flow path, the interfacial tension contrary to the moving direction of the liquid a stop exerting, provided in the flow path, the flow path has a reaction portion is provided to detect unit or reaction to detect, the detection unit or reaction portion, the more the stops The present invention provides a liquid feeding device provided in front of the liquid moving direction .

In the liquid delivery device according to the first aspect, the interface portion formed in the middle of the liquid moving in the flow path is stopped at the stop portion in the flow path, so that the fluid is stopped at a specific position in the flow path. It can be made.
In the liquid delivery device according to the first aspect, when at least the first and second liquids separable by the interfacial tension are put into the flow path, the interface between the first and second liquids is located at the stop portion. Thus, the first and second liquids can be stopped.
Furthermore, even when the liquid in the flow path is moved by an external force, the liquid can be stopped in a state where the interface formed in the middle of the liquid is located at the stop portion.

Further, the present invention is a liquid feeding device in which a detection unit or a reaction unit is provided in a flow path, and the liquid feeding method moves the liquid in the flow path by the action of interfacial tension. An introduction part for introducing a liquid into the liquid delivery device, and a stop part are provided, and the stop part is provided between the introduction part and the detection part or the reaction part. A first liquid that is a target liquid to be fed and a second liquid that is a driving liquid are introduced in this order, and the stop portion is an interface formed between the first liquid and the second liquid. In addition, by supplying an interfacial tension opposite to the moving direction of the liquid and stopping the movement of the liquid at least temporarily, only the first liquid reaches the detection unit or the reaction unit. A method is provided.

In the liquid feeding method according to the first aspect, since the liquid moving in the flow path can be stopped at the position of the stop portion by the interface formed in the middle of the liquid, the liquid can be fed by an appropriate amount. .
In the liquid feeding method according to the first aspect, when at least the first and second liquids separable by the interfacial tension are put into the flow path, the liquid is fed by the interface between the first and second liquids at the position of the stop portion. Since the liquid can be stopped, the second liquid can be sent to a predetermined position even if the amount of the first liquid is smaller than the volume of the flow path.
Furthermore, in the liquid feeding method according to the first aspect, even when the liquid in the flow path is moved by an external force, the liquid can be stopped at the position of the stop portion by the interface between the first and second liquids.
Moreover, according to the liquid feeding method according to the first aspect, since the interface is formed, the second liquid is not mixed with the first liquid.

Furthermore, the present invention provides a micro analysis chip using the liquid feeding device.
According to the micro- analysis chip according to the first aspect, the liquid can be accurately moved and stopped without using a micro pump or a control device for controlling the movement and stop of the liquid in the flow path, so that the configuration is simple. Thus, the size can be reduced.

Furthermore, the present invention provides an analyzer using the microanalysis chip.
Such analyzers are small, portability is good, it improves use freely.

By providing the stop portion in the channel, the liquid tip can be stopped at a specific position other than the end of the channel in the series of channels. This eliminates the need for an end to stop the liquid. Further, since the interface between the liquid and the liquid or the liquid and the gas can be stopped by the stop portion and the liquid feeding can be stopped, it is not necessary to define the filling amount. A sufficient amount of liquid can be filled to feed the flow path through the capillary force. Furthermore, when a liquid having a low boiling point such as oil is used as the second liquid following the first liquid, it is possible to prevent a change in volume and concentration due to vaporization of the liquid. Thereby, the influence by the difference in the elapsed time from filling and an external environment can be suppressed.
Feeding apparatus and feeding method according to the present invention, despite a simple structure, it is possible to perform feed control with high reliability. Therefore, the micro-analysis chip and the analysis apparatus using the same are remarkably effective in improving usability and downsizing.

It is a figure which shows the liquid feeding apparatus which concerns on Embodiment 1 of this invention, Comprising: Fig.1 (a) is a top view, FIG.1 (b) is sectional drawing. It is a top view for demonstrating the flow of the liquid of the liquid feeding apparatus which concerns on Embodiment 1 of this invention. FIG. 3A is a pillar structure diagram illustrating an example of a stop portion of the present invention, and FIG. 3A is a plan view in a flow path, and FIG. 3B is a perspective view in a flow path. It is a figure which shows the liquid feeding apparatus which concerns on Embodiment 2 of this invention, Comprising: Fig.4 (a) is a top view, FIG.4 (b) is sectional drawing. It is a top view for demonstrating the flow of the liquid of the liquid feeding apparatus which concerns on Embodiment 2 of this invention. It is a top view which shows the liquid feeding apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the flow of the liquid by the electrowetting valve | bulb of the liquid feeding apparatus which concerns on Embodiment 3 of this invention. It is a figure for demonstrating the flow of the liquid of the liquid feeding apparatus which concerns on Embodiment 3 of this invention. It is a perspective view which shows the analyzer which concerns on Embodiment 4 of this invention. It is a figure which shows the liquid feeding apparatus which concerns on a prior art, Comprising: Fig.10 (a) is a top view, FIG.10 (b) is sectional drawing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
1A and 1B are diagrams showing a liquid feeding device according to Embodiment 1, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view. As shown in FIGS. 1 (a) and 1 (b), the liquid delivery device according to the first embodiment is configured to flow a liquid that is provided on the upstream side of the flow path 3 and the flow path 3 for moving the liquid. An introduction part 1 that is, for example, a hole to be introduced into the path, and a discharge part such as a hole provided on the downstream side (opposite to the introduction part 1) of the flow path 3 for discharging air or the like in the flow path 3 2, a stop portion 4 for controlling the movement of the liquid is provided in the flow path 3 near the introduction portion 1. Details of the stop unit 4 will be described later. The liquid that moves in the flow path 3 is a target liquid that is a target of liquid feeding and a driving liquid that moves the target liquid.

In the present embodiment, the flow path 3 is formed by bonding the first substrate 5 and the second substrate 6, and the groove formed in the back surface of the first substrate 5 is formed by the second substrate 6 on the flat plate. It has a structure with a lid. Therefore, the first substrate 5 is made of a polydimethylsiloxane material (PDMS) that can be processed, and the second substrate 6 is made of a glass material.
The thickness of the first substrate 5 is about 0.1 mm to 10 mm, and the thickness of the second substrate 6 is 0.0.
It is about 1 mm to 10 mm. The introduction part 1 and the discharge part 2 may be through holes having a diameter of 10 μm or more formed in the first substrate 5.

The flow path 3 formed by the first substrate 5 and the second substrate 6 can feed the liquid to be fed by capillary action, but is moved by applying the external force F from the introduction portion 1. Is also possible. Liquid feeding by this capillary phenomenon can be performed when the contact angle with respect to the liquid on the channel surface is 90 degrees or less.
Here, the flow of the liquid in the microchannel using the capillary force will be described. The force of flowing liquid due to the capillary force is greatly affected by the contact angle between the channel wall surface and the liquid. When the wall surface of the flow path is made of a uniform material and the cross-sectional shape perpendicular to the direction of travel of the flow path is a circle, the pressure acting on the liquid (pressure of liquid feeding due to capillary action) P is the interfacial tension at the gas-liquid interface. Where σ is the channel wall contact angle θ, and the channel radius is r.
P = 2σ cos θ / r (Formula 1)
In Equation 1, when P is positive, that is, cos θ is positive, the liquid can travel through the space in the flow path, and when P is 0 or negative, that is, when cos θ is 0 or negative, the liquid Stops without going through the space in the flow path. Thus, the movement of the liquid due to the capillary force is related to the value of the contact angle θ.

Here, when the liquid is water, the case where the contact angle measured under conditions of 1 atm and 25 ° C. using pure water (25 ° C.) having a specific resistance larger than 18 MΩ · cm is less than 90 ° is hydrophilic. It is called sex. Hydrophobic means that the contact angle of the pure water is 90 ° or more. However, since the action of the contact angle in the liquid feeding direction varies greatly in the vicinity of 90 °, the hydrophilicity in the present invention is preferably such that the contact angle with respect to pure water is 85 ° or less, and the contact angle is 60 ° or less. It is more preferable that
Further, the interfacial tension that determines the capillary phenomenon may be improved by subjecting the first substrate 5 and the second substrate 6 to a hydrophilic treatment. For example, it may be hydrophilized by hydrophilic treatment treatment, plasma treatment, UV treatment, hydrophilic film coating, or surface roughness control. That is, the first substrate 5 and the second substrate 6 may not be hydrophilic due to the characteristics of the substrates themselves (for example, material and surface shape).
The channel refers to a channel having such a size that capillary action occurs, and includes, for example, a channel whose width or height is about 0.1 micrometer to about 10 millimeters. The width or height of the flow path is preferably 10 micrometers to 1 millimeter.

  Further, materials other than PDMS and glass may be used for the first substrate 5 and the second substrate 6. The material of these substrates may be selected according to the purpose and application of the liquid delivery device, and is not particularly limited to PDMS or the like. For example, when the liquid delivery device is used for liquid analysis and optical detection is performed, in order to optically detect the liquid in the liquid delivery device, a transparent or translucent material may be used for these substrates. . You may select the material with little light emission by the excitation light by fluorescent substance. Examples of such a transparent or translucent material include glass, quartz, thermosetting resin, thermoplastic resin, and film. In addition, silicon resins, acrylic resins, and styrene resins are preferable from the viewpoint of moldability as well as transparency. In addition, as a plastic material that emits less light by excitation light from phosphors, it can be used as a fluorine-based plastic material such as fluorinated polymethyl methacrylate in which hydrogen atoms of polymethyl methacrylate are replaced with fluorine atoms, and as an additive for catalysts and stabilizers. Examples include polymethyl methacrylate using a member that does not emit fluorescence.

<Liquid and stop part 4>
The stopping portion 4 is a portion where the interface tension acting between the liquid and the other portion in the flow path acts differently, so that the pressure P against the driving liquid or gas-liquid interface becomes 0 or negative. Provided. For example, when the wall surface of the flow path 3 is used as the stop portion 4, the portion 4 is subjected to a hydrophilic treatment, and a difference is provided between the wall surface of the other flow paths. In short, the surface state of the stop portion has a lower contact angle with the liquid than the surface state of other portions in the flow path. Thereby, the contact angle of the driving liquid with respect to the channel wall surface can be increased. Alternatively, by providing a constricted portion with respect to the cross-sectional area of the flow channel perpendicular to the liquid traveling direction, the interface tension of the driving liquid with respect to the flow channel can be increased to form the stop portion 4.
Examples of the structure of the narrowed portion include a pillar structure, a columnar shape, a circular shape, an elliptical shape, a semicircular shape, and a triangular shape. As shown in FIG. 3, the pillar structure 7 is a structure in which a plurality of (three in FIG. 3) square pillars are arranged in the flow path 3 in a direction crossing the liquid flow. The width or height is preferably 1 micrometer to 1100 micrometers, and more preferably 30 micrometers to 50 micrometers.
According to the above configuration, portions having different contact angles may exist on the flow path surface, and the capillary phenomenon generated in the flow path is determined by the sum of the respective interfacial tensions. The tension is obtained, and the interfacial tension is integrated according to the composition ratio. In the case of the liquid 1, the cos θ that is the sum of the interfacial tensions may be positive, and the pressure P acting on the entire flow path can be obtained. .

FIG. 2 shows the flow of liquid when two kinds of liquids 8 and 9 are fed into the flow path 3 shown in FIG. 1 and stopped. As the liquid 8 to be fed and the driving liquid 9, a liquid that is formed by an interface tension and does not mix is selected. In order to send the liquid by capillary force, it is preferable to use an aqueous liquid as the target liquid 8 positioned in front of the liquid traveling direction and an oily liquid as the driving liquid 9. For example, oil can be used as the oily liquid, and examples include vegetable oil, mineral oil, and silicone oil. According to the said structure, the liquid-liquid interface is formed between the object liquid 8 and the driving liquid 9, and it can isolate | separate without mixing by interface tension. Further, by using an oily liquid for the driving liquid 9, vaporization of the liquid can be suppressed. Thereby, not only the liquid amount of the target liquid 8 can be kept constant, but also the concentration of the target liquid 8 can be prevented.
Moreover, by adjusting the viscosity of the driving liquid 9 in addition to the interfacial tension, the liquid feeding speed can be suppressed and the liquid feeding can be stopped.
According to the above configuration, since the liquid-gas interfacial tension and the gas have a higher kinematic viscosity than the liquid, the stop portion 4 can stop the liquid feeding.

The interfacial tension of the liquid can be calculated by measuring the contact angle with the flow path wall. The viscosity can be measured using a capillary viscometer, a falling ball viscometer, or a rotational viscometer.
Therefore, it is possible to design a structure capable of stopping liquid feeding by combining the flow channel surface state and the flow channel shape with respect to the types of the liquids 8 and 9.
For example, when the flow path has a quadrangular cross section with respect to the liquid traveling direction, the liquid feeding speed v due to capillary action is γ _LV , viscosity η, flow path height h, When the width is w and the contact angle of the channel wall surface is θ, it is expressed by the following equation 2.


... (Formula 2)
From this, when the liquid feeding speed due to the capillary phenomenon of the liquid 8 in the flow path 3 is v1, and the liquid feeding speed due to the capillary phenomenon of the liquid 9 in the stop portion is v2, the type of liquid is such that v1 and v2 are substantially balanced. What is necessary is just to select the structure of a stop part. In addition, since the pillar structure 7 can be designed simultaneously with another flow path when producing the first substrate, it is preferable from the viewpoint of ease of production.

In FIG. 2, the liquid feeding operation will be described. First, the target liquid 8 is filled from the introduction unit 1, and a driving liquid 9 that is not mixed with the target liquid 8 is filled behind the target liquid 8. That is, the liquids 8 and 9 that can be separated by the interfacial tension are sequentially introduced while being in contact with each other. The liquids 8 and 9 flow toward the discharge part 2 due to the effects of their own weight and interfacial tension, and the target liquid 8 is a liquid in which a positive pressure acts in the moving direction on both the flow path and the stop part. The liquid is fed by the capillary force and passes through the stop portion 4. In contrast, the driving liquid 9 exerts a positive pressure in the movement direction on the flow path, but in the stop portion 4, the pressure is zero or negative, so the liquid interface is When the stop part 4 is reached, the liquid feeding stops. More precisely, when the direction in which the liquids 8 and 9 are fed by the capillary force F1 is a positive direction, the interface tension P1 received by the front interface of the target liquid 8 is the positive direction, and the driving liquid 9 Since the interfacial tension P2 received by the front interface is negative, it is only necessary to provide a stop 4 that balances the combined force of F1 and P1 with P2.
Therefore, even if the required amount of the target liquid 8 as a sample is small, if the stop unit 4 is provided at a position corresponding to the required amount, the target liquid 8 subsequently moves the driving liquid 9 from the introduction unit 1 to the stop unit. If it is introduced in a larger amount (amount A1) than the flow path volume B1 up to 4, the target liquid 8 moves reliably toward the discharge part 2 without stopping in the flow path up to the stop part 4.

On the other hand, when the driving liquid 9 reaches the stop 4, a negative pressure is generated by the action of the interfacial tension, so that the drive liquid 9 does not move before the stop 4, so that the target liquid 8 is moved to a predetermined position. I can do it. Since the two liquids 8 and 9 are originally separable by the difference in interfacial tension and are not mixed with each other, the components of the target liquid 8 are not contaminated by the driving liquid 9.
The amount of the driving liquid 9 is not limited to A1, but may be an amount that gives the target liquid 8 in the flow path 3 a force that moves toward the discharge portion 2 by capillary force.
Further, instead of introducing the liquids 8 and 9 in contact with each other as described above, when the driving liquid 9 is introduced after the target liquid 8 and further behind the gas, the liquid is fed by the capillary force F2 received by the liquid. The interface tension P3 received by the front interface of the target liquid 8 faces in the positive direction, and the interface tension P4 received by the front interface of the driving liquid 9 faces in the negative direction. The stop portion 4 may be provided so that at least the combined force consisting of at least the interfacial tension P4 and the external force F2 and the interfacial tension P3 is substantially balanced.

The contents of the present invention will be described more specifically with reference to examples.
(Example 1)
The basic structure of the liquid delivery device according to Example 1 is the same as that of the first embodiment. With reference to FIG. 2, the liquid delivery apparatus of Example 1 will be described more specifically.
The formation of the channel groove on the first substrate 5 was performed by a resin molding method using a mold. The mold was manufactured by forming a resist pattern on a silicon substrate by a photolithography method and then performing an etching by a dry etching process method. The width of the flow path 3 was 600 μm, the height of the flow path 3 was 50 μm, the length of the flow path 3 was 15 mm, and a pillar structure 7 having a width of 30 μm was provided as a stop structure at a position 5 mm downstream from the introduction portion.

The mold was provided with a mold, and silicon rubber (polydimethylsiloxane, Toray Dow Corning Zilpot 184) was poured until the thickness became 2 mm, and heated at 100 ° C. for 15 minutes to be cured. After curing, the mold and the cured silicone rubber were separated.
Next, the silicon rubber was shaped into a length of 20 mm, a width of 10 mm, and a thickness of 2 mm, and a through-hole having a diameter of 1 mm was opened as a lead-in part and a discharge part by using a punch to produce the first substrate 5. The inner surface of the manufactured first substrate 5 was subjected to oxygen plasma treatment under the conditions of 100 W, an oxygen flow rate of 30 sccm, and 60 seconds to increase the hydrophilicity of the inner surface of the first substrate 5.

The second substrate 6 was prepared by cutting a Tempax glass substrate having a thickness of 600 μm into a length of 25 mm and a width of 15 mm with a dicing saw.
The manufactured first substrate and the second substrate were superposed on each other to produce a liquid feeding device according to Example 1.
A liquid feeding test was performed on the liquid feeding apparatus according to Example 1.
0.2 μl of glycine buffer was dropped into the introduction part, and 1 μl of silicone oil KF-96-350cs (manufactured by Shin-Etsu Silicone), which is an oily liquid, was further dropped from the introduction part. The glycine buffer solution flowed through the flow path 3 by capillary force, passed through the stop portion 4, and liquid feeding stopped when the silicone oil reached the stop portion 4.

(Comparative Example 1)
As a comparative example, a liquid delivery apparatus similar to that of Example 1 was prepared except that no stop portion was provided. With respect to the liquid feeding device according to the comparative example, an experiment for flowing a liquid was performed in the same manner as in Example 1.
In Comparative Example 1, when a glycine buffer solution is dropped into the introduction portion and silicone oil is further dropped, the glycine buffer solution enters the flow channel in the liquid feeding device due to capillary action, and the glycine buffer solution does not stop in the middle of the flow channel. Silicone oil was delivered to the discharge section.
From the above, in Example 1, it was confirmed that the silicone oil, which is an oily liquid, could not pass through the stop portion and the liquid feed stopped, whereas in Comparative Example 1, the glycine buffer solution was fed to the discharge portion. From this, it was confirmed that the liquid feeding apparatus of Example 1 can stop liquid feeding.

(Embodiment 2)
Next, a second embodiment of the liquid delivery device in the present invention will be described. 4A and 4B are diagrams showing a liquid feeding device according to Embodiment 2, in which FIG. 4A is a plan view and FIG. 4B is a cross-sectional view. The liquid delivery apparatus according to Embodiment 2 is characterized in that the liquid delivery is stopped at the stop unit 4 by the interfacial tension between the liquid and the gas.
<Bubble generation electrode>

In the present embodiment, a bubble generating electrode 10 for generating bubbles in the liquid is provided in the flow path 3 from the introduction portion 1 to the stop portion 4. In order to form electrodes on the surfaces of the flow path 3, the first substrate 5, and the second substrate 6, the substrate material may be a material capable of forming electrodes. Examples of materials capable of forming such an electrode include materials such as glass, quartz, and silicon from the viewpoints of productivity and reproducibility. When the flow path is formed on the first substrate 5, it is difficult to form the electrode on the uneven portion. Therefore, the electrode may be formed on the second substrate 6 where the flow path is not formed. The electrode material may be a general electrode material such as gold, platinum, silver, silver chloride, copper, iridium, aluminum, ITO (indium tin oxide), nickel, titanium, or chromium. The shape of the working electrode and the counter electrode is not particularly limited, such as a circular shape, a square shape, or a linear shape, but it is preferable to ensure a size corresponding to the current value.
<Liquid>

Examples of a method for generating gas include a method of generating bubbles from dissolved gas by electrolysis or heating of water by applying a voltage to an electrode. Thus, in order to generate bubbles by electrolysis at a low voltage, the liquid needs to be an aqueous liquid containing an electrolyte. Examples of the electrolyte include sodium chloride and potassium chloride. In the case of the present embodiment, liquid feeding can be stopped with only one type of liquid. However, an oily liquid may be filled behind the liquid as in the first embodiment.
Other configurations may be the same as those in the first embodiment.

FIG. 5 shows the liquid flow. The liquid 8 is introduced from the introduction part 1 and fed by capillary force. Bubbles 11 are generated by applying a voltage to the bubble generating electrode 10 while the liquid 8 is being fed. When the bubble 11 reaches the stop portion 4, the pressure applied to the stop portion 4 becomes negative due to the interfacial tension, so that the liquid 8 is stopped from being sent from the bubble 11.
In the case of the second embodiment, if the bubbles 11 are generated, the liquid can be stopped by the stop portion 4 at a predetermined location, so that the movement in the flow path 3 can be easily controlled. In addition, in the prior art, there is an apparatus that generates a large amount of bubbles and stops the movement of the liquid by using the interface tension of the gas-liquid interface at the end of the flow path. The second embodiment is different from the second embodiment in that it can be stopped only by the connecting portion. According to this embodiment, the liquid can be stopped at an arbitrary position in the flow path.
Therefore, even if the required amount of the liquid 8 as a sample is small, by introducing a larger amount of the liquid 8 from the introduction unit 1, the capillary force is sufficiently applied, and the liquid 8 is in the flow path 3. In addition, the bubbles 8 can be generated in the middle of the liquid feeding to feed the liquid 8 to a predetermined position in the flow path 3.
Further, even when the driving liquid 9 is put into the flow path 3 behind the liquid 8 and sent, the necessary amount of the liquid 8 is divided by the bubbles generated by the bubble generating electrode 10 and only the necessary amount is obtained. It is also possible to send the liquid to the discharge unit 2.
(Embodiment 3)

Next, as a third embodiment, a microanalysis chip 62 using the liquid feeding device according to the present invention will be described. FIG. 6 shows a microanalysis chip according to the third embodiment.
The micro analysis chip 62 includes a main flow path 33 including a detection unit 34 therein, and an open hole 21 for introducing liquid into one of the main flow paths 33 and an air hole 24 formed in the other. Yes. Also, open holes 22 and 23 for introducing liquid into the chip are provided through introduction channels 27 and 28, respectively, and connected to the main channel 33. The main channel 33 is further provided with a discharge part 25 via a discharge channel 26 in the vicinity of the opening 21.
The first and second introduction flow paths 27 and 28 and the discharge flow path 26 are provided with first to third valves 29, 30 and 31 for opening and closing the liquid flow, respectively. Moreover, an absorber is enclosed in the discharge part 25. A stop portion 32 similar to the stop portion 4 is provided in the introduction flow path 27 between the open hole 22 and the valve 29.

Microanalysis chip according to the present embodiment is formed by bonding a first substrate having a groove made in the same manner as in the flow path in the first embodiment is formed and a second substrate to the cover of the first substrate However, the description of the components of the first and second embodiments is omitted, and the other parts are described.
<Detector 34>

The main channel 33 is provided with a detection unit 34 that detects the amount of a specific substance contained in the liquid. For example, when the detection unit 34 is an electrochemical detection means, the detection unit 34 is provided with a working electrode, a reference electrode, and a counter electrode. As a material for the working electrode, the reference electrode, and the counter electrode, common electrode materials may be used. For example, gold, platinum, silver, silver chloride, copper, iridium, aluminum, ITO, nickel, titanium, chromium, or the like may be used. it can.
In addition, the shape of the working electrode, the reference electrode, and the counter electrode can be circular, square, linear, or the like, and is not particularly limited. The size should be ensured in accordance with the detected current value. For example, in the case of a circular shape, the outer diameter is about 10 μm to 10 mm, and preferably the outer diameter is about 0.5 mm to 5 mm. Even in the case of a shape other than a circle, it is preferable that the area is approximately the same as the area in the case of a circle.

When the detection unit 34 is a means for detecting by a change in impedance, for example, an electrode for impedance detection is provided in the detection unit. The electrode material for impedance detection may be a general electrode material such as gold, platinum, silver, silver chloride, copper, iridium, aluminum, ITO, nickel, titanium, chromium, etc.
In the case where the detection unit 34 is a means for performing fluorescence detection, for example, a fluorescence detection unit is provided on the side surface or bottom surface of the flow path.
<Reaction part>

Instead of the detection unit 34, or together with the detection unit 34, a reaction unit that performs an antigen-antibody reaction or an enzyme reaction can be provided. In the case of performing an enzyme reaction, for example, an enzyme used for the enzyme reaction is immobilized on the side surface or bottom surface of the flow path or in the flow path. Moreover, it is also possible to use a method in which a liquid containing an enzyme flows to the reaction part.
When an antigen-antibody reaction is performed, the antibody or antigen used for the antigen-antibody reaction can be immobilized in the flow channel as described above. In addition, a liquid containing an antibody or an antigen can be flowed to the reaction part.
The shape of the reaction part that performs the antigen-antibody reaction or the enzyme reaction is not particularly limited.
<valve>

The valves 29, 30, and 31 can stop the liquid filled from the open hole in the introduction flow path. As a result, the liquid can be fed sequentially or simultaneously in a state of being filled with a plurality of liquids.
As the bulbs 29, 30, and 31, electrowetting bulbs and light bulbs can be used. In addition, a structure is provided in which a hydrophobic part is provided on a part of the wall surface of the flow path, a pressable part is provided on the upstream side of the flow path, and the liquid in the flow path is sent out beyond the hydrophobic part by applying pressure from the outside. It can be. In addition, a hydrophobic part provided on the wall surface of the flow path and an electrode part for electrolyzing the liquid in the flow path on the upstream side of this to generate bubbles are generated. The structure can be made to exceed the sex part.

FIG. 7 shows the flow of liquid by the electrowetting valve. FIG. 7A shows a state where the voltage application is OFF, and FIG. 7B shows a state where the voltage application is ON.
As shown in FIG. 7, the electrowetting valve includes a working electrode 45 and a reference electrode 44 for switching between stopping and advancing of the liquid, and these electrodes are hydrophilic substances constituting one surface of the inner wall surface of the flow path. The surface of the working electrode 45 is treated so as to be hydrophobic. When the voltage application is OFF, the surface of the working electrode 45 is hydrophobic, so that the liquid cannot pass through the working electrode 45. On the other hand, when a voltage is applied between the working electrode 45 and the reference electrode 44 (about 0.8 V to 2.0 V), the electrode surface of the working electrode 45 changes to the hydrophilic side, so that the liquid that has stopped Can be moved forward (see FIG. 7B). The materials for the working electrode and the reference electrode are not particularly limited, and general conductive materials can be used. For example, gold, platinum, silver, silver chloride, copper, iridium, aluminum, ITO, nickel, titanium, chromium, etc. can be used.
Further, in order to ensure the liquid stopping function, a hydrophobic film such as a tetrafluoroethylene film or a very low hydrophilic film such as a natural oxide film of an electrode metal is provided on the surface of the working electrode 45. deep.
<Absorber>

The absorber enclosed in the discharge part 25 is a structure that absorbs liquid, and includes materials such as fibers, porous bodies, water-absorbing polymers, polymer gels, and structures formed of these materials. Examples thereof include sodium polyacrylate fine particles, cotton, glass fibers, molecular sieves (zeolite) powder, and a fine structure formed of a resist.
When the liquid solvent to be absorbed is water, it is preferable to use a hydrophilic material. When the hydrophilicity of the material itself is low or absent, the material may be subjected to a hydrophilic treatment. For example, it may be hydrophilized by hydrophilic treatment treatment, plasma treatment, UV treatment, hydrophilic film coating, or surface roughness control.

This micro-analysis chip can control the introduction and transfer of a plurality of liquids. For example, an antibody or the like is immobilized on the detection unit 34, and a liquid containing an antigen is allowed to flow by causing a liquid containing an antigen to flow, thereby causing a liquid containing an enzyme-labeled antibody to flow. Immunoassay in which the antigen-antibody reaction is performed by flowing, the substrate solution is further flown to cause the enzyme-substrate reaction, and the amount of the electrode active substance generated by the enzyme-substrate reaction is detected by the detection electrode, thereby measuring the amount of the antigen. It can be used for antigen measurement using the method.
By performing the liquid feeding procedure shown in FIG. 8, a specific substance can be measured using this microanalysis chip.

(1) The antibody is immobilized on the detection electrode provided with the detection unit 34. The opening hole 22 is filled with the substrate solution 52 and the oil 53, and the opening hole 23 is filled with the cleaning solution 54. At this time, since the second valve 30 and the third valve 31 are closed, the substrate solution 52 and the cleaning solution 54 send the first introduction channel 27 and the second introduction channel 28 by capillary force. After being liquefied, the valves 30 and 31 are stopped.

(2) A sample liquid 51, which is a mixed solution of the specimen and the enzyme-labeled antibody after pretreatment (separation, dilution, decomposition), is introduced into the main channel 33 from the open hole 21 (FIG. 8-a). After the sample liquid 51 is sent to the air hole 24, the sample liquid 51 is stopped for a certain period of time in order to cause the specific substance contained in the sample liquid to react with the antibody immobilized on the detection electrode (FIG. 8-b). Thereafter, the first valve 29 is opened, and the sample liquid 51 is discharged to the discharge unit 25 provided with the absorber (FIG. 8-c).

(3) In order to clean the inside of the main flow path 33 with the cleaning solution 54, the third valve 31 is opened, and the cleaning solution 54 is introduced from the introduction flow path 28 into the main flow path 33 and directly to the discharge section 25. Discharge (FIGS. 8-d, e).

(4) In order to send the substrate solution for reacting with the enzyme remaining on the detection electrode to the main channel 33, the second valve 30 is opened and the substrate solution 52 is introduced from the introduction channel 27. . The interface between the substrate solution 52 and the oil 53 is stopped by the stop portion 32, and only a required amount is sent to the main channel 33 (FIG. 8-f). Thereafter, the enzyme and the substrate are reacted for a certain time.

(5) The reactant generated on the detection electrode 34 is electrochemically detected by the detection electrode 34 and the amount of the specific substance in the sample liquid 51 is measured.
As the liquid feeding stop method, the method of Embodiment 2 may be used by providing a bubble generating electrode in the flow path from the open hole 22 to the stop portion 32 in the microanalysis chip of the present embodiment.
(Embodiment 4)

The fourth embodiment relates to a portable handy analyzer. The contents of the fourth embodiment will be described with reference to FIG. FIG. 9 is a conceptual diagram for explaining the outline of a portable handy analyzer according to the fourth embodiment.
This handheld microanalyzer is composed of a microanalytical chip 62 and a control handy device 61 that drives and controls the microanalytical chip. The micro analysis chip 62 is the same micro analysis chip as described in the third embodiment. Therefore, detailed description of the micro analysis chip is omitted here.

As shown in FIG. 9, a chip connection port 63 into which the micro analysis chip 62 is inserted is provided in the lower part of the control handy device 61, and the micro analysis chip 62 is formed at the back of the chip connection port 63. An external input / output terminal (not shown) that is electrically connected to the external connection terminal 64 is provided.
The external connection terminal 64 is used to input drive power and drive information from the outside to the chip, and to output detection results and the like to the outside. When a gold thin film is used for the formation of the terminal, the external connection terminal can be formed in the same manner as the electrowetting valve and the detection electrode, so that the production efficiency is good. Of course, other conductive materials such as copper, iron or aluminum may be used instead of gold.

When the external connection terminal 64 of the micro analysis chip 62 is inserted into the chip connection port 63, the external input / output terminal in the control handy device 61 and the external connection terminal 64 of the micro analysis chip 62 are electrically connected.
The control handy device 61 has a display unit 65 that can display the measurement result of the analysis chip (amount of the substance to be detected, etc.), and various data for specifying measurement parameters. An input unit 66 is provided. As the input unit 66, for example, a touch panel structure can be adopted.

Furthermore, although not shown, the control handy device 61 incorporates an information processing system such as a CPU that can process data and an I / O logic circuit that processes input information and output information.
The micro analysis chip 62 is connected to the control handy device 61, various data are input, and the measurement start button is pushed. As a result, liquids such as reagent liquids and sample liquids (test liquids) that have been previously provided in the microanalysis chip and that have stopped flowing into the flow path by the open / close valve sequentially enter the flow path. As a result, a predetermined reaction is performed in each flow path to become a detectable substance to reach the detection unit, where an electrical signal corresponding to the amount of the substance to be detected is generated. This electrical signal is output from the external connection terminal 64 to the outside.

  The signal output from the external connection terminal 64 is received by the external input terminal of the control handy device 61 electrically connected to the external connection terminal 64, and this signal is stored in software information stored in the control handy device 61 in advance. Analyze based. Thereby, the quantity or type of the substance to be detected can be specified.

  As described above, according to the present invention, it is possible to realize a compact liquid feeding apparatus that can switch between stopping and advancing of liquid with a simple operation with a simple structure. Such a liquid feeding device can be used as a microanalysis chip that performs reaction and detection within the chip, and the industrial applicability of the present invention is great.

DESCRIPTION OF SYMBOLS 1 Introduction part 2 Discharge part 3 Flow path 4 Stop part 5 1st board | substrate 6 2nd board | substrate 7 Pillar structure 8 Liquid 1 (target liquid)
9 Liquid 2 (driving liquid)
10 Bubble generating electrode 11 Bubble 21 Open hole 1
22 Open hole 2
23 Opening hole 3
24 Air hole 25 Discharge unit 26 Discharge channel 27 First introduction channel 28 Second introduction channel 29 First valve 30 Second valve 31 Third valve 32 Stop unit 33 Main channel 34 Detection unit 35 Substrate 41 First substrate 42 Second substrate 43 Flow path 44 Working electrode 45 Reference electrode 51 Sample liquid 52 Substrate solution 53 Oil 54 Cleaning solution 61 Control device 62 Micro analysis chip 63 Chip connection port 64 External connection terminal 65 Display unit 66 Input Part

Claims (14)

A liquid feeding device that moves at least a first liquid that is a target liquid to be fed and a second liquid that is a driving liquid that can be separated by interfacial tension in the flow path by the action of interfacial tension. In
The interface formed between the first liquid and the second liquid located in the flow path, a stop for exerting a surface tension opposite to the direction of movement of the liquid, provided in the flow path The flow path is provided with a detection unit for performing detection or a reaction unit for performing reaction,
The detection unit or reaction unit is provided in front of the liquid moving direction from the stop unit,
Liquid delivery device. The liquid feeding device according to claim 1,
Said stop portion, feeding device characterized by consisting of different shapes, surface condition, or stenosis from other portions of the flow channel. In the liquid feeding device according to claim 1 or 2,
Contact angles with respect to the liquid of the wall surface of the flow path is not more than 90 degrees,
The contact angle with respect to the liquid stop portion, liquid delivery device wherein the flow path than the contact angle of the other part is in. In the liquid feeding device according to any one of claims 1 to 3,
Feeding apparatus characterized by comprising an electrode upstream of the flow channel from the stop to the advancing direction of the liquid. The liquid feeding device according to claim 4, wherein
The liquid feeding device , wherein the first liquid is an aqueous liquid containing an electrolyte . In a liquid delivery apparatus provided with a detection part or a reaction part in a flow path, a liquid feed method for moving the liquid in the flow path by the action of interfacial tension,
The liquid feeding device is provided with an introduction portion for introducing a liquid into the liquid feeding device, and a stop portion,
The stop unit is provided between the introduction unit and the detection unit or reaction unit,
A first liquid that is a target liquid to be fed and a second liquid that is a driving liquid are introduced in this order into the introduction section;
The stopping unit applies an interfacial tension to the interface formed between the first liquid and the second liquid in the direction opposite to the moving direction of the liquid to stop the movement of the liquid at least temporarily. A liquid feeding method that causes only the first liquid to reach the detection unit or the reaction unit . In the liquid feeding method according to claim 6,
An aqueous liquid as the first liquid and an oily liquid as the second liquid are introduced into the flow path . In the liquid feeding method of Claim 6 or Claim 7,
A liquid feeding method , wherein a liquid having a higher viscosity than the first liquid is introduced into the flow path as the second liquid. In the liquid feeding method according to any one of claims 6 to 8,
A flow path that is connected to the introduction section and allows a liquid to flow downstream; and a discharge section that is provided on the downstream side of the flow path that discharges gas or liquid in the flow path,
The liquid feeding method, wherein the volume of the first liquid is made smaller than the volume of the flow path from the introduction section to the stop section, and the volume of the second liquid is at least equal to or larger than the volume of the flow path. . In the liquid feeding apparatus of any one of Claims 1-5 ,
In the flow path, a valve capable of switching the liquid in a stopped state to forward is provided.
A liquid feeding device characterized by that. The liquid delivery device according to claim 10 , wherein
The liquid feeding device , wherein the valve is an electrowetting valve . In the liquid feeding device according to any one of claims 1 to 5, 10, and 11,
A liquid feeding device, wherein a liquid absorber is provided . Microanalysis chip comprising the liquid delivery device according to any one of claims 1～5,11～12. An analysis apparatus using the micro analysis chip according to claim 13 .