JP3890328B2 - Holder for biosensor - Google Patents

Description

The present invention relates to a biosensor holder.

  Conventionally, various electrochemical sensors have been used. Examples of the electrochemical sensor include a gas sensor, a pressure sensor, a concentration sensor, a temperature sensor, an enzyme sensor, and the like. In various measurements, a change amount is converted into an electric signal to obtain a target measurement amount.

For example, a semiconductor-type gas sensor using SnO ₂ or the like for low-concentration CO gas detection has been proposed (see Non-Patent Document 1).

Tokoyama, "Study on high functional environmental sensor by sol-gel method", Mie Prefectural Industrial Technology Research Institute report, 2000, No. 24, p. 79-83

  The gas sensor described in Non-Patent Document 1 has an advantage that aging is unnecessary and handling is easy. However, since it is a semiconductor system, there is a problem that the selectivity is poor because it reacts with components other than the target gas.

  For this reason, there is a demand for an electrochemical sensor that is simple and has high gas selectivity. In addition to the semiconductor sensors described above, various sensors have been proposed. In order to perform stable measurement in these simple and highly selective electrochemical sensors, an aging process for the electrochemical sensor is required. It may be necessary.

  Specifically, the aging process is a process of applying a constant potential to the electrodes constituting the electrochemical sensor so as to maintain a stable charge at the electrode interface. This aging process particularly requires that the electrochemical sensor is not used, that is, it is aged immediately when not used. In this case, after applying a predetermined potential to the electrochemical sensor, the influence of impurities on the electrode surface of the electrochemical sensor is eliminated, and the sensor output is stable until the electric double layer is formed on the electrode surface. An aging process is needed to keep changing.

  When this electrochemical sensor is used as a disposable one, if the aging process is performed every time the electrochemical sensor is replaced, there is a problem that it takes time to measure the target measurement target. is there. In order to solve this problem, it is desirable that the aging process of the electrochemical sensor is performed in advance, the electrochemical sensor is attached to the detector body during measurement, and a predetermined measurement is performed.

  For example, a disposable electrochemical sensor includes an example of an alcohol sensor used for alcohol measurement for the purpose of controlling drunk driving. This alcohol sensor is commercially available as an alcohol sensor kit including an alcohol sensor that measures alcohol and a holder that supports the alcohol sensor (see Non-Patent Document 2).

[Search October 8, 2003], Internet <URL: http://akizukidenshi.com/catalog/items2.php?c=alcohol>

  However, in the measurement with the above alcohol sensor, when the alcohol sensor is replaced with another alcohol sensor, the electric potential is temporarily reduced due to the discharge of the electric charge kept constant by the aging process. Therefore, there is a problem that the effect of restoring the sensor output of the alcohol sensor, that is, the so-called aging effect is lost.

  In addition, a procedure may be considered in which an electrochemical sensor is attached to a predetermined detector body, subjected to aging treatment for a certain period of time, and measurement is started, but each time the electrochemical sensor is used, a certain amount of time for aging treatment is required. Therefore, there is a problem that continuous measurement is impossible. At this time, if a plurality of predetermined detectors are prepared in order to perform continuous measurement, an aging process can be performed, but a problem of high cost arises.

It is an object of the present invention to provide a holder for a biosensor that can eliminate such conventional problems and can maintain the aging effect.

In order to solve the above problem, the holder for the biosensor of the present invention has a sensor insertion opening for fixing the biosensor at the time of measurement by the time of the aging process and biosensors, the bio-sensor fixed in the sensor insertion port An application means is provided which is electrically connected via an electrode, and the biosensor maintains an applied voltage during the aging process .

The electrochemical sensor holder of the present invention, the application means is rather preferably a capacitor, also, the electrodes, the disposed opposite inside of the holder for the biosensor, the terminal in the biosensor It is preferable to have an electrode terminal which contacts, and a terminal exposure part which exposes an electrode terminal to the outer peripheral surface of the said biosensor holder .

When the biosensor holder of the present invention is used, the applied potential during aging of the biosensor is maintained by the applying means, so that, for example, the aging unit can be replaced with a detector while maintaining the aging effect. A biosensor holder that can be provided can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a biosensor holder 1 according to an embodiment of the present invention. Here, FIG. 1 is a cross-sectional view of the electrochemical sensor holder 1, and FIG. 2 is a plan view of the bottom surface side of the biosensor holder 1.

[Configuration of holder for biosensor ]
As shown in FIGS. 1 and 2, the biosensor holder 1 has a cylindrical case 2 and a fixing portion that opens to the bottom surface side of the case 2 and fixes a biosensor 6 as an electrochemical sensor to be described later. As the sensor insertion port 2A, the electrode terminals 3 and 4 which are arranged opposite to each other inside the case 2 and come into contact with the terminals of the biosensor 6 described later inserted from the sensor insertion port 2A, and the ceiling of the case 2 And a capacitor 5 as application means provided on the surface side.

  As shown in FIG. 2, the case 2 has a terminal exposed portion 2 </ b> B that exposes the electrode terminals 3 and 4 on the outer peripheral surface of the side surface. The case 2 is formed in a cylindrical shape, but is not limited thereto, and may be a polygonal cylindrical member such as a triangular tube or a square tube. In short, the operability during the aging process of the biosensor 6 is improved. Any shape and size that does not hinder can be used as appropriate.

As shown in FIG. 2, the sensor insertion opening 2 </ b> A is substantially the same size as the cross-sectional dimension in the insertion direction of the biosensor 6 and is formed in a rectangular shape. The sensor insertion port 2A is substantially the same size as the cross-sectional dimension of the biosensor 6 in the insertion direction, and is formed in a rectangular shape. What is necessary is just to have a fixing part which can fix biosensor 6 to holder 1 for biosensors separately from sensor insertion slot 2A. Examples of the other fixing portion include a clamp that holds the proximal end side of the biosensor holder 1.

  As shown in FIG. 1, the electrode terminals 3 and 4 are made of an electrically conductive member. As shown in FIG. 2, the electrode terminals 3 and 4 are exposed from the terminal exposed portion 2B and electrically connected to an external detector or the like. Is done.

  As shown in FIG. 1, the capacitor 5 as the application means is a rectangular chip capacitor that fits within the range of the ceiling surface of the case 2, and is electrically connected to the electrode terminals 3 and 4.

  Although the capacitor 5 is used as the application means, the application voltage is not limited to this, and the applied voltage is maintained while the electrochemical sensor is fixed so that the aging effect which is the object of the present invention can be maintained. For example, various application means can be employed as long as it can store electric power. Examples of the application means include a secondary battery that is miniaturized to such an extent that it can be mounted on the case 2. The capacitor 5 is provided on the ceiling surface side of the case 2, but is not limited thereto, and may be provided inside the case 2.

  On the other hand, as an electrochemical sensor, in various measurements such as a gas sensor, a pressure sensor, a concentration sensor, a temperature sensor, an enzyme sensor, etc., various amounts that can convert a change amount into an electrical signal and measure a target value. An electrochemical sensor can be adopted. In this embodiment, the biosensor 6 is illustrated as an electrochemical sensor.

  This biosensor 6 is used as an alcohol sensor. The biosensor 6 is used for an alcohol sensor, but is not limited to this. The biosensor 6 may be used for various applications as appropriate, and the structure may be changed as appropriate according to the application.

[Configuration of biosensor]
FIG. 3 is an exploded perspective view of the biosensor 6.
As shown in FIG. 3, the biosensor 6 is formed by supporting an enzyme on a porous carrier 7A, and the sensitive portion 7 that exposes its surface to the extent that an enzyme reaction is possible, the first internal insulating material 8 and the first 1 is insulated from each other by the external insulating material 10 and by the second internal insulating material 11 and the second external insulating material 13, and is electrically coupled to the sensitive portion 7 and substantially to the sensitive portion 7 And a pair of electrodes consisting of a first electrode 9 and a second electrode 12 formed in a non-stacked state.

Furthermore, the biosensor 6 shown in FIG. 3 includes a sensitive portion 7 having a substantially rectangular sheet shape,
A sheet-like first internal insulating material 8 affixed to the sensitive part 7 so as to cover a part of one surface of the sensitive part 7 at one end of the sensitive part 7;
A first electrode 9 formed on a surface of the first internal insulating material 8 opposite to the sensitive portion 7 and electrically contacting the sensitive portion 7;
The first electrode 9 is sandwiched between the first internal insulating material 8 and the surface of the first electrode 9 at the end opposite to the sensitive portion 7 is exposed. A first external insulating material 10 forming a laminate with the internal insulating material 8 and the first electrode 9;
The sensitive part 7 is affixed to the sensitive part 7 so as to cover a part of the surface on the opposite side of the first internal insulating material 8 and the sensitive part 7 is affixed. A sheet-like second internal insulating material 11 in which the entire non-existing portion is affixed to the first internal insulating material 8;
The surface of the sensitive part 7 to which the second internal insulating material 11 is affixed, the entire surface not covered by the second internal insulating material 11 is covered, and the second internal insulating material 11 A second electrode 12 covering the entire surface opposite to the surface to which the first internal insulating material 8 is attached;
The second electrode so that the second electrode 12 is sandwiched between the second inner insulating material 11 and the surface of the second electrode 12 at the end opposite to the sensitive portion 7 is exposed. 12, a second external insulating material 13 formed on the surface of the second internal insulating material 11 and the second electrode 12 to form a laminate,
Comprising.

  In the embodiment shown in FIG. 3, one end portion of the first internal insulating material 8 overlaps the one end side surface of the sensitive portion 7 formed in a sheet shape, and the second internal insulating material 11 is disposed on the one end side rear surface of the sensitive portion 7. One end of each overlaps.

  From the tip of the second internal insulating member 11 on the sensitive portion 7 side to the tip of the sensitive portion 7 (the end opposite to the end of the sensitive portion 7 to which the second internal insulating member 11 is joined) is the second. 11 A of contact spaces for the electrode 12 to contact the sensitive part 7 are formed. From the end where the first internal insulating material 8 is joined to the sensitive part 7, the first electrode 9 is in electrical contact with the sensitive part 7, and the first electrode 9 is in contact with the sensitive part 7. The sensitive part 7 ahead from the part is exposed.

  The sensitive part 7 is formed by carrying an enzyme on the porous carrier 7A and exposes its surface to the extent that an enzyme reaction is sufficiently possible.

  When the biosensor shown in FIG. 3 is simply used as an alcohol sensor for detecting alcohol in breath, the enzyme is preferably alcohol oxidase.

  The biosensor shown in FIG. 3 preferably immobilizes the enzyme on the porous carrier 7A by a comprehensive method. As a comprehensive method in this case, a method of immobilizing an enzyme on a porous carrier by impregnating the porous carrier with a mixed solution of alcohol oxidase and a photocrosslinkable resin, drying in a cool and dark place, and then irradiating with light Can be mentioned.

  A preferable example of the photocrosslinkable resin is a water-soluble photosensitive polymer (PVA-SbQ) containing polyvinyl alcohol (PVA) and formylstyrylpyridinium (FSbQ) salt.

  The first internal insulating material 8 has a function of sandwiching the first electrode 9 with the first external insulating material 10 to form a laminated body, and making the first electrode 9 and the second electrode 12 insulated. Have.

  As shown in FIG. 3, the first internal insulating material 8 is preferably formed of an insulating material such as polyolefin such as polyethylene. As shown in FIG. 3, the first internal insulating material 8 has a sheet shape or a strip shape, and specifically has a thickness of 0.001 to 1 mm and a width (width) of 0.05 to 20 mm. The vertical dimension is a thin piece arbitrarily determined from the viewpoint of the type, scale, cost, etc. of the biosensor.

  As shown in FIG. 3, the first internal insulating material 8 is affixed to the sensitive part 7 so as to overlap a part of one flat surface at one end of the sensitive part 7 having a sheet shape. . The sensitive part 7 and the first internal insulating material 8 may be attached with an adhesive, and if the first internal insulating material 8 is a thermoplastic resin such as polyolefin, it is bonded by thermal fusion. You may do it.

  As shown in FIG. 3, the first electrode 9 covers a part of the surface of the sensitive part 7 so as to be in electrical contact with the sensitive part 7, and is in contact with the sensitive part 7 of the first internal insulating material 8. It is formed so as to cover the entire surface opposite to the surface. The first electrode 9 can be formed of various materials as long as it has conductivity.

  Examples of materials that can form the first electrode 9 include metals such as aluminum, nickel, copper, platinum, gold, and silver, conductive metal oxides such as ITO, and carbon materials such as carbon fibers and carbon nanotubes. Can be mentioned.

  The first external insulating material 10 can form a laminate by sandwiching the first electrode 9 with the first internal insulating material 8, and can insulate the first electrode 9 from the second electrode 12. As long as various forms can be adopted.

  In the biosensor 6 shown in FIG. 3, the first external insulating material 10 is formed in a strip-shaped sheet, and the surface of the first electrode 9 covered by the first internal insulating material 8 Is attached so as to cover the surface of the first electrode 9 on the opposite side from the end on the sensitive part 7 side to the predetermined position from the end on the opposite side. In the biosensor 6 shown in FIG. 3, the surface of the first electrode 9 exposed without being covered with the first external insulating material 10 forms a terminal 14 for taking out an electric signal.

  The first external insulating material 10 can be formed of the same material as that of the first internal insulating material 8, and is preferably formed of polyolefin, particularly polyethylene, like the first internal insulating material 8.

  The first external insulating material 10 shown in FIG. 3 has a sheet shape or a strip shape, and specifically has a thickness of 0.001 to 1 mm and a width (width) of 0.05 to 20 mm. The dimension is a thin piece that is arbitrarily determined from the viewpoint of the type, scale, and cost of the biosensor.

  The second internal insulating material 11 has a function of sandwiching the second electrode 12 with the second external insulating material 13 to form a laminated body and making the first electrode 9 and the second electrode 12 insulated. Have. As long as it has such a function, the second internal insulating material 11 can be formed using various insulating materials. As a suitable insulating material capable of forming the second internal insulating material 11, like the first internal insulating material 8, polyolefins such as polyethylene, polypropylene and polybutene can be exemplified.

  The second internal insulating material 11 is preferably formed of an insulating material such as polyolefin such as polyethylene. The second internal insulating material 11 shown in FIG. 3 has a sheet shape or a strip shape, and specifically has a thickness of 0.001 to 1 mm and a width (width) of 0.05 to 20 mm. The dimension is a thin piece that is arbitrarily determined from the viewpoint of the type, scale, and cost of the biosensor.

  As shown in FIG. 3, the second electrode 12 has an entire surface opposite to the surface of the sensitive portion 7 that is partially covered with the first internal insulating material 8 so as to be in electrical contact with the sensitive portion 7. And covering the entire surface of the second internal insulating material 11 opposite to the surface in contact with the sensitive portion 7. The second electrode 12 can be formed of various materials as long as it has conductivity. The conductive material forming the second electrode 12 is the same as the material capable of forming the first electrode 9.

  As with the first electrode 9, the second electrode 12 is preferably formed by a printing method in which a conductive paste is printed. The second electrode 12 is preferably formed by a printing method using a conductive paste such as carbon paste to form a working electrode.

  The second external insulating material 13 can form a laminate by sandwiching the second electrode 12 with the second internal insulating material 11, and can insulate the second electrode 12 from the first electrode 9. As long as various forms can be adopted.

  In the biosensor 6 shown in FIG. 3, the second external insulating material 13 is formed in a strip-like sheet, and is opposite to the end of the second external insulating material 13 on the sensitive portion 7 side. Affixed to cover a predetermined position from the end on the side.

  In the biosensor 6 shown in FIG. 3, the surface of the second electrode 12 exposed without being covered with the second external insulating material 13 forms a terminal 15 for taking out an electric signal.

  The second external insulating material 13 can be formed of the same material as that of the first internal insulating material 8, and is preferably formed of polyolefin, particularly polyethylene, like the first internal insulating material 8. The second external insulating material 13 shown in FIG. 3 has a sheet shape or a strip shape, and specifically has a thickness of 0.001 to 1 mm and a width (width) of 0.05 to 20 mm. The dimension is a thin piece that is arbitrarily determined from the viewpoint of the type, scale, and cost of the biosensor.

  For example, the biosensor 6 shown in FIG. 3 includes the second external insulating material 13, the second electrode 12, the second internal insulating material 11, the first internal insulating material 8, and the first electrode. 9 and the first external insulating material 10 are laminated in this order, one end of the first internal insulating material 8 and one end of the second internal insulating material 11 sandwich the one end of the porous carrier 7A, and the second A part of one end of the electrode 12 covers a part of the surface of the sensitive part 7 so that the second electrode 12 and the sensitive part 7 are electrically coupled, and the surface of the sensitive part 7 is capable of an enzymatic reaction. The second electrode 12 covers the surface opposite to the exposed surface of the sensitive portion 7 and is electrically coupled. On the other hand, the first electrode 9 and the second electrode The end surface on the opposite side of the twelve sensitive portions 7 is exposed so as to function as a terminal. Formed by formed in a stick-shaped laminate of single Te.

Procedure Using the holder and biosensors for biosensors
The procedure for using the biosensor holder 1 and the biosensor 6 will be described below with reference to FIGS. FIG. 4 is an explanatory diagram illustrating the principle of the device configuration for detecting a predetermined component by the biosensor 6. FIG. 5 is a schematic diagram showing a state when the biosensor 6 is subjected to an aging process.

[Measurement with biosensor 6]
First, after performing an aging process described later, the biosensor 6 is used. After performing this aging process, the biosensor 6 is connected to a detector or the like to start measurement. As shown in FIG. 4, the electrode terminals 3 and 4 in the biosensor holder 1 are connected to, for example, a potentiostat 16. The potentiostat 16 applies a constant potential to the electrode of the biosensor 6 and measures the current generated in the electrode during sample measurement. Under the present circumstances, the front-end | tip part of the biosensor 6 is the state which has brought the measuring object close to the position which can be measured.

  Next, the detected current detected by the potentiostat 16 is converted into a digital signal by the AD converter 17, a digital signal corresponding to this detected signal is taken into the computer 18, and a calibration curve stored in the computer 18 is obtained. Thus, the concentration of the substance detected by the biosensor 6 can be calculated, and the concentration of the substance can be displayed on the monitor 19 as display means.

[Aging process of biosensor 6]
Next, as shown in FIG. 5, after the measurement of the biosensor 6 is completed, an aging process is performed. First, although not shown, an aging unit for performing an aging process is electrically connected to the electrode terminals 3 and 4 in the biosensor holder 1.

  Furthermore, at least the sensitive part of the biosensor 6 is immersed in the buffer solution filled in the buffer solution tank 20. Thereafter, current flows from an aging unit (not shown), the sensor output of the biosensor 6 is monitored, and when the current reaches a predetermined current, the aging process is terminated. At this time, since the electrode terminals 3 and 4 and the capacitor 5 are connected during the aging process, the electric charge is accumulated in the capacitor 5, and when the aging is completed, the electric charge is sufficiently accumulated in the capacitor 5. It becomes.

Note that if the biosensor 6 as an electrochemical sensor is taken out from the biosensor holder 1 and left as it is, the potential held by the biosensor 6 decreases and re-aging before measurement is required. It is necessary to keep the biosensor 6 in the biosensor holder 1 just before. In addition, the time during which this neglect is allowed is in a range in which the interelectrode potential does not substantially decrease.

According to this embodiment as described above, the following effects are obtained.
(1) Since the capacitor 5 as the application means is provided, the biosensor 6 is fixed at the sensor insertion port 2A as the fixing portion, and electric power is stored in the capacitor 5, so that the applied voltage during aging is maintained. The aging effect can be sustained.

(2) Since the application means is the capacitor 5, the capacitor itself is inexpensive, so that the material cost can be reduced.

(3) The sensor insertion port 2A is substantially the same size as the cross-sectional dimension of the electrochemical sensor 2 in the insertion direction, and is formed in a rectangular shape, so that the electrochemical sensor 2 is only inserted into the sensor insertion port 2A. Thus, the electrochemical sensor 2 can be fixed to the biosensor holder 1.

(4) Since the electrode terminals 3 and 4 are exposed from the terminal exposed portion 2B and the terminal exposed portion 2B is formed on the outer peripheral portion of the side surface of the case 2, an external detector, an aging unit, etc. Can be easily connected to.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention. The specific structure, shape, and the like at the time of carrying out the present invention may be other structures or the like as long as the object of the present invention can be achieved.

It is sectional drawing of the holder for biosensors which concerns on this invention. It is a top view of the bottom face side of the holder for biosensors of FIG. It is an exploded perspective view of the biosensor, which is fixed to the holder for the biosensor of FIG. It is principle explanatory drawing which shows in principle the apparatus structure which detects a predetermined component with a biosensor. It is the schematic which shows the state at the time of carrying out an aging process of a biosensor.

Explanation of symbols

1 Biosensor holder 2 Case 2A Sensor insertion slot (fixed part)
2B Terminal exposed part 3 Electrode terminal 4 Electrode terminal 5 Capacitor (applying means)
6 Biosensor (electrochemical sensor)
DESCRIPTION OF SYMBOLS 7 Sensing part 7A Porous support | carrier 8 1st internal insulation material 9 1st electrode 10 1st external insulation material 11 2nd internal insulation material 11A Contact space 12 2nd electrode 13 2nd external insulation material 14 Terminal 15 Terminal 16 Potentiostat 17 AD converter 18 Computer 19 Monitor 20 Buffer liquid tank

Claims (3)

It has a sensor insertion port for fixing the biosensor at the time of aging treatment and measurement by the biosensor ,
It is electrically connected via an electrode to the biosensor that is fixed in the sensor insertion port, a biosensor wherein the application means the biosensor to maintain the applied voltage at the time of aging treatment is provided holder. 2. The biosensor holder according to claim 1, wherein the applying means is a capacitor.   The electrodes are disposed opposite to each other inside the biosensor holder, and have electrode terminals that contact the terminals of the biosensor, and terminal exposed portions that expose the electrode terminals on the outer peripheral surface of the biosensor holder. The biosensor holder according to claim 1, wherein the holder for biosensor is provided.

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