JP2005043122A - Biosensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biosensor capable of smoothly introducing a liquid sample to be measured into a reserving space part without leaving air bubbles and simple in constitution. <P>SOLUTION: The liquid sample is smoothly introduced into the reserving space part S without leaving air bubbles by forming a protruded part 51 to the single side of a spacer 5 for forming the reserving space part S to accelerate the introduction of the liquid sample into the reserving space part S due to a capillary phenomenon on the side of the protruded part 51. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a biosensor attached to a measuring device that measures a specific component in a liquid sample.
[0002]
Conventionally, a disposable biosensor that can easily measure a specific component in a liquid sample such as urine, blood, and body fluid collected from a living body without dilution has been proposed (see, for example, Patent Document 1). . As shown in FIG. 8, this biosensor 100 is detachably attached to a measuring apparatus, and introduces a liquid sample such as blood brought into contact with the inlet 101 into the holding space 102 using a capillary phenomenon, Electrochemical changes due to the enzyme reaction of the liquid sample are detected by the electrode parts 103 and 104.
[0003]
However, in order to smoothly flow the liquid sample brought into contact with the introduction port 101 into the reservation space portion 102, the biosensor 100 extracts the gas in the reservation space portion 102 to the outside separately from the introduction port 101. Therefore, there is a problem that the configuration of the biosensor is complicated.
[0004]
[Patent Document 1]
Japanese Examined Patent Publication No. 6-58338
[Problems to be solved by the invention]
The present invention was made in view of the above-described drawbacks of conventional biosensors, and without providing an exhaust port for extracting gas in the storage space, without leaving bubbles in the storage space, An object of the present invention is to provide a biosensor with a simple configuration capable of smoothly introducing a liquid sample.
[0006]
[Means for Solving the Problems]
In the present invention, a substrate and a cover are arranged to face each other with a spacer at the tip, and a holding space formed by the substrate, the cover and the edge of the spacer is provided with a reaction part containing an enzyme. Introducing a liquid sample from the front end of the sensor into the holding space using capillary action, and detecting an electrochemical change due to an enzymatic reaction between the liquid sample and the reaction part at an electrode part including a measurement electrode and a counter electrode A biosensor that
In the holding space portion, a protruding portion that protrudes toward the front end side of the sensor is formed on one side of the front end edge of the spacer.
[0007]
Further, the present invention is characterized in that a corner portion is formed at a leading edge of the spacer.
[0008]
Furthermore, the present invention provides a reaction in which an enzyme is contained in a holding space formed by the substrate, the cover, and the leading edge of the spacer, wherein the substrate and the cover are opposed to each other with a spacer at the tip. An electrode including a measurement electrode and a counter electrode for introducing an electrochemical change due to an enzymatic reaction between the liquid sample and the reaction unit into the storage space by introducing a liquid sample from the front end side of the sensor into the storage space. A biosensor for detecting at a part,
In the storage space, protrusions protruding toward the sensor front end are formed on both sides of the front end edge of the spacer, and a notch is formed in the front end edge of the cover.
[0009]
Furthermore, the cut portion reaches the leading edge of the spacer.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the biosensor 10 according to the embodiment of the present invention will be described with reference to FIGS.
[0011]
1 and 2, what is indicated by reference numeral 1 is an electrically insulating substrate made of PET (polyethylene terephthalate) resin. The substrate 1 of the present embodiment is formed in a long plate shape having a length of 22 mm, a width of 7 mm, and a thickness of 250 μm, and its tip is formed in a substantially semicircular shape.
[0012]
What is indicated by reference numeral 2 is an electrode portion disposed on the substrate 1. The electrode part 2 is composed of a measuring electrode 21 and a counter electrode 22 which are arranged substantially in parallel along the longitudinal direction of the substrate 1. In this embodiment, two electrode films obtained by sputtering a platinum film on a polyimide film having a length of 21.7 mm, a width of 1 mm, and a thickness of 25 μm are adhered to the substrate 1 with an adhesive at an interval of 0.5 mm. Part 2 is configured.
[0013]
What is indicated by reference numeral 3 is an electrically insulating coating layer laminated on the substrate 1 in order to partially cover the electrode portion 2. The covering layer 3 includes a substantially oval opening 31 on the tip end side having a substantially semicircular shape, and the tip end side of the electrode portion 2 is exposed through the opening 31. The covering layer 3 is not laminated on the rear end side of the substrate 1 and exposes the rear end side of the electrode portion 2. Thus, the exposed portion on the front end side of the electrode portion 2 is used as a detection portion for detecting an electrochemical change due to an enzyme reaction between the reaction portion 4 and the liquid sample described below, and the rear end side exposure of the electrode portion 2 is performed. The part is used as a connection terminal for connection to a measuring device. In the present embodiment, a hot melt film having a length of 17 mm, a width of 7 mm, and a thickness of 65 μm having a substantially semicircular tip is laminated as a coating layer 3 on the substrate 1 by thermocompression bonding.
[0014]
What is indicated by reference numeral 4 is a reaction part disposed on the detection part of the electrode part 2 in the opening part 31 of the coating layer 3. The reaction unit 4 includes an enzyme that reacts with a specific component of a liquid sample to be measured and an electron donor that confers electrons during the enzyme reaction. In this embodiment, the reaction part 4 is comprised by melt | dissolving an enzyme and an electron donor in a solvent (for example, water), apply | coating this solution to the opening part 31, and drying.
[0015]
What is indicated by reference numeral 5 is an electrically insulating spacer disposed on the coating layer 3 except for the substantially semicircular portion at the tip of the coating layer 3. A protrusion 51 that protrudes toward the sensor front end 15 is formed on one side in the width direction of the leading edge of the spacer 5, and a corner 52 is formed at the base of the protrusion 51. In the present embodiment, a PET film having an adhesive layer on both sides of a length of 13.5 mm, a width of 7 mm, and a thickness of 150 μm excluding the protruding portion 51 is laminated on the coating layer 3 as a spacer 5.
[0016]
What is indicated by reference numeral 6 is an electrically insulating cover disposed on the spacer 5. The front end portion of the cover 6 is formed in a substantially semicircular shape slightly smaller than the front end portion of the substrate 1. In the semicircular portion of the cover 6, the cover 6 and the substrate 1 are arranged to face each other with a predetermined interval by a spacer 5. As a result, on the sensor tip 15 side, a holding space portion S surrounded by the upper surface of the coating layer 3 and the reaction portion 4 on the substrate 1, the lower surface of the cover 6, and the tip edge of the spacer 5 is formed. In the present embodiment, a transparent PET film having a length of 16.8 mm, a width of 7 mm, and a thickness of 125 μm is laminated as the cover 6 on the upper surface of the spacer 5.
[0017]
When measuring a liquid sample using the biosensor 10 configured as described above, first, the biosensor 10 is attached to the measuring device at its rear end, and then the liquid sample to be measured is attached to the tip 15 of the biosensor 10. And the liquid sample is introduced into the storage space S using a capillary phenomenon. Then, the specific component of the liquid sample and the reaction portion 4 are enzymatically reacted in the reserved space portion S, the electrochemical change at that time is detected by the electrode portion 2, and the specific component in the liquid sample is measured by the measuring device. is there.
[0018]
In this biosensor 10, the protruding portion 51 is formed on one side of the leading edge of the spacer 5, so that the liquid sample flowing from the sensor leading end 15 side by capillary action can be brought into contact with the protruding portion 51 first. Then, the introduction of the liquid sample by capillary action can be promoted by the protrusion 51 using the wettability of the protrusion 51. Therefore, as shown in FIG. 3, after the front edge F of the liquid sample flowing in from the sensor tip 15 side contacts the protrusion 51, the liquid sample is preferentially placed from one side along the side of the protrusion 51. The liquid sample can be smoothly introduced into the entire storage space S while discharging the gas in the storage space S to the opposite side of the protrusion 51 (see arrow C in FIG. 3). .
[0019]
In addition, when the gas is discharged to the opposite side of the protruding portion 51, the discharged airflow C prevents the liquid sample from coming into contact with the spacer 5 in other portions than the protruding portion 51 and creating bubbles. The liquid sample can be introduced without leaving any bubbles in the storage space S.
[0020]
Furthermore, since the biosensor 10 can introduce a liquid sample from one side along the projecting portion 51 by the introduction promoting action of the projecting portion 51, the corner portion 52 is formed in the spacer 5 at the back of the storage space portion S. Even in this case, no bubbles are left in the corner 52.
Therefore, according to the biosensor 10, unlike the conventional case, the formation of the entrance corner portion is not limited due to remaining bubbles, and the capacity of the storage space portion S can be easily increased by the formation of the entrance corner portion. it can.
[0021]
Furthermore, since the biosensor 10 can support the cover 6 by the protruding portion 51 protruding toward the sensor tip 15 side, the set interval between the substrate 1 and the cover 6 can be stably maintained. Therefore, for example, it is possible to prevent the cover 6 and the like from being deformed due to a temperature change, an external force, etc., and a liquid sample can be introduced into the storage space S according to a specified amount, and an accurate measurement with little measurement error can be achieved. Is possible.
[0022]
As mentioned above, although one Embodiment of this invention was described, the biosensor which concerns on this invention can be implemented also with another form.
[0023]
For example, the biosensor 20 shown in FIGS. 4 and 5 may be used. The biosensor 20 is characterized by the spacer 7 and the cover 8. Other configurations are the same as those of the biosensor 10 described above, and the description thereof is omitted using the same reference numerals.
[0024]
The spacer 7 of the biosensor 20 has protrusions 71 that protrude toward the sensor tip 25 on both sides in the width direction of the tip edge, and a corner 72 is formed at the root of each protrusion 71. . In this modified example, a PET film having an adhesive layer on both sides of a length of 13.5 mm, a width of 7 mm, and a thickness of 150 μm excluding the protruding portion 71 is laminated on the coating layer 3 as a spacer 7.
[0025]
The front end of the cover 8 is formed in a substantially semicircular shape slightly smaller than the front end of the substrate 1, and a slit-shaped cut portion 81 is formed at the front end edge of the substantially semicircular shape. The cover 8 is disposed on the upper surface of the spacer 7, and the cover 8 and the substrate 1 are disposed to face each other at a predetermined interval by the spacer 7 in a semicircular portion of the cover 8.
Thus, on the sensor front end 25 side, a holding space portion S surrounded by the upper surface of the coating layer 3 and the reaction portion 4 on the substrate 1, the lower surface of the cover 8, and the front end edge of the spacer 7 is formed. In this modification, a transparent PET film having a length of 16.8 mm, a width of 7 mm, and a thickness of 125 μm is laminated as the cover 8 on the upper surface of the spacer 7. As shown in FIG. 5, the cut portion 81 is formed so as to reach from the center in the width direction of the front end edge of the cover 8 to the center portion in the width direction of the front end edge of the spacer 7.
[0026]
Since the biosensor 20 has a cut portion 81 formed at the tip edge of the cover 8, even if the protrusions 71 are formed on both sides of the tip edge of the spacer 7, the liquid sample can be smoothly retained in the space without leaving bubbles. Part S can be introduced.
[0027]
That is, the biosensor 20 uses the wettability of the protrusion 71 to promote the introduction of the liquid sample by the capillary phenomenon at the protrusion 71, and at the same time uses the gap of the notch 81 to generate the liquid by the capillary phenomenon at the notch 81. The introduction of the sample can be suppressed. Therefore, as shown in FIG. 5, the inflow of the liquid sample flowing in from the sensor tip 25 side is suppressed by the notches 81 at the center thereof, but the inflow is promoted by the protrusions 71 on both sides thereof, and is suspended. While the gas in the space S is discharged from the notch 81 (arrow C in FIG. 5), the liquid sample can be smoothly introduced without leaving bubbles in the entire storage space S.
[0028]
In the biosensor 20, the cut portion 81 is formed so as to reach the leading edge of the spacer 7 to facilitate the discharge of the gas in the storage space portion S. Of course, the biosensor according to the present invention is not limited thereto. For example, the leading edge of the spacer 7 does not have to be reached like the cut portion 82 of the biosensor 30 shown in FIG. 6 or the cut portion 83 of the biosensor 40 shown in FIG. 7.
[0029]
As described above, the cut portion not only suppresses the introduction of the liquid sample due to the capillary phenomenon in the gap, but also serves to discharge the gas in the storage space portion S. Therefore, as in the biosensor 40 shown in FIG. 7, when the front edge F of the liquid sample that has flowed in from the sensor tip 45 side contacts the protrusion 71 and the inflow is promoted, the storage space S is cut. As long as the portion 83 communicates with the outside, the gas in the storage space portion S can be discharged at the communicating portion of the cut portion 83. In addition, since the liquid sample can be prevented from blocking the communicating portion of the cut portion 83 by the discharged air flow C, the liquid sample can be smoothly introduced without leaving bubbles in the storage space S. is there. If the cut portions are formed short like the cut portions 82 and 83, the strength against deformation of the cover 8 can be maintained, and a more accurate measurement of the liquid sample becomes possible.
[0030]
Further, various changes can be made to the shape of the cut portion, and the gap interval may be increased toward the tip as in the cut portion 83 of the biosensor 40 to form a substantially V shape. As a result, the inflow suppressing action at the initial inflow of the liquid sample can be increased, and the reliability of gas discharge can be increased. As described above, the biosensor according to the present invention has various design changes with respect to the width, length, shape, and the like of the gap of the cut portion in consideration of, for example, the type of the liquid sample, the capacity of the reserved space portion S, the interval, and the like. Is possible.
[0031]
In addition, the present invention can be implemented in a mode in which various improvements, changes, and modifications are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention. In addition, within a range where the same action or effect is produced, any invention specific matter may be replaced with another technology, and the integrally configured invention specific matter may be made up of a plurality of members. Even if comprised, you may implement with the form which comprised the invention specific matter comprised from the several member integrally.
[0032]
【The invention's effect】
As described above, according to the biosensor according to the present invention, the introduction of the liquid sample by capillary action can be promoted on one side of the reservation space part by the protrusion formed on one side of the back part of the reservation space part. Thus, unlike the prior art, there is no need to provide an exhaust port for extracting gas in the inner part of the holding space part, and the liquid sample can be smoothly introduced without leaving bubbles in the holding space part with a simple configuration.
[0033]
In addition, the cut portion formed at the tip of the holding space portion can suppress the introduction of the liquid sample due to the capillary phenomenon, and the cut portion can discharge the gas in the holding space portion. In addition, it is not necessary to provide an exhaust port for extracting gas in the inner part of the storage space, and the liquid sample can be smoothly introduced without leaving bubbles in the storage space with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a biosensor of the present invention, where FIG. 1 (a) is a plan view and FIG. 1 (b) is a cross-sectional view along line AA.
FIG. 2 is an exploded perspective view of the biosensor of the present invention.
FIG. 3 is a partial plan view illustrating an introduction process when a liquid sample is introduced into the storage space of the biosensor of the present invention.
FIG. 4 is an exploded perspective view of a modified example of the biosensor of the present invention.
FIG. 5 is a partial plan view for explaining an introduction process when a liquid sample is introduced into the storage space portion of the modified example of the biosensor of the present invention.
FIG. 6 is a partial plan view for explaining an introduction process when a liquid sample is introduced into a holding space portion according to another embodiment of the biosensor of the present invention.
FIG. 7 is a partial plan view for explaining an introduction process when a liquid sample is introduced into a storage space portion of still another modified example of the biosensor of the present invention.
8A and 8B are diagrams showing a conventional biosensor, where FIG. 8A is a perspective view and FIG. 8B is an exploded perspective view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Electrode part 21 Measuring electrode 22 Counter electrode 3 Covering layer 4 Reaction part 5 Spacer 51 Protrusion part 52 Corner part 6 Cover 7 Spacer 71 Projection part 72 Corner part 8 Cover 81 Cut part 10, 20, 30, 40 Enzyme sensor 15, 25, 35, 45 Sensor tip S Reservation space

Claims (4)

A substrate and a cover are arranged to be opposed to each other with a spacer at the tip, and a holding space formed by the substrate, the cover and the edge of the spacer is provided with a reaction part containing an enzyme,
A liquid sample is introduced from the front end side of the sensor into the holding space part by utilizing capillary action, and an electrochemical change due to an enzymatic reaction between the liquid sample and the reaction part is detected by an electrode part including a measurement electrode and a counter electrode. A biosensor,
The biosensor according to claim 1, wherein a protruding portion that protrudes toward a sensor front end side is formed on one side of a front end edge of the spacer in the holding space portion. The biosensor according to claim 1, wherein a corner portion is formed at a leading edge of the spacer. A substrate and a cover are arranged to be opposed to each other with a spacer at the tip, and a holding space formed by the substrate, the cover and the edge of the spacer is provided with a reaction part containing an enzyme,
A liquid sample is introduced from the front end side of the sensor into the holding space part by utilizing capillary action, and an electrochemical change due to an enzymatic reaction between the liquid sample and the reaction part is detected by an electrode part including a measurement electrode and a counter electrode. A biosensor,
The biosensor according to claim 1, wherein in the holding space portion, a protruding portion that protrudes toward the sensor tip side is formed on both sides of a tip edge of the spacer, and a cut portion is formed in the tip edge of the cover. The biosensor according to claim 3, wherein the cut portion reaches a leading edge of the spacer.

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