JP5381936B2 - Biosensor - Google Patents

Description

  The present invention relates to a biosensor using an electrode having translucency.

  In recent years, diabetes patients are increasing year by year in each country. In the treatment of diabetes, for example, there is insulin therapy. Insulin is known as a drug that controls blood sugar levels. In this therapy, insulin, which is a therapeutic agent for diabetes, is administered to diabetic patients. The need to administer insulin is determined based on the blood glucose level of the diabetic patient. For this reason, it is essential for a diabetic patient to grasp the blood glucose level. The blood glucose level is the glucose concentration in the blood. The blood glucose level is obtained by measuring the glucose concentration in the blood. Therefore, development of simple self-blood glucose measuring devices that can be easily handled by diabetic patients at home has been actively conducted.

  A method using a biosensor in a simple self-blood glucose measuring device as described above is known. An enzyme is used for the biosensor. Glucose in the blood is quantified using a specific reaction of the enzyme. Glucose is quantified by a GOD method in which glucose is decomposed into gluconic acid by glucose oxidase (hereinafter sometimes abbreviated as “GOD”), and glucose is abbreviated as glucose dehydrogenase (hereinafter, “GDH”). GDH method of decomposing into gluconolactone is known.

  Electrons are generated when the enzyme specifically breaks down glucose. The generated electrons move to the working electrode of the electrode pair of the biosensor. This movement of electrons causes a current to flow through the electrode pair of the biosensor. The content of glucose in the blood is calculated from the magnitude of this current. That is, a blood sugar level is obtained. In addition, the presence of an electron mediator that carries electrons makes it possible to obtain stable measurement values. Examples of the electron mediator include organic compounds such as potassium ferricyanide, hexaammineruthenium and quinone derivatives, or organic-metal complexes.

  Two types of biosensors are known. One is a three-dimensional type in which a working electrode and a counter electrode are arranged to face each other with a space separated in the thickness direction of the biosensor. The other is a planar type in which a working electrode and a counter electrode are arranged on the same substrate. This planar biosensor is disclosed in Patent Document 1 and Patent Document 2.

JP 2005-003679 A Japanese Patent Laid-Open No. 05-203608

  In order to reduce the burden on the diabetic patient, it is desirable that the amount of the sample to be introduced into the sample space of the biosensor, for example, blood, is very small. For this purpose, the biosensor is miniaturized and designed so that the volume of the space into which blood is introduced and the opening for introducing blood into the space are as small as possible. When blood glucose is measured, a diabetic patient contacts the collected blood with the opening of the biosensor and waits for blood to be guided to the sample space by capillary action. In such an operation, a diabetic patient tries to visually confirm the position of the opening of the biosensor for introducing blood and whether the blood has reached the sample space. However, when the volume of the space including the opening of the biosensor and the sample side portion becomes small, there arises a problem that it is difficult to visually confirm these. This problem is particularly noticeable in patients with decreased vision such as the elderly.

  In order to solve the above-described problem, a mark or the like indicating a place where blood is to be introduced into the biosensor is printed. Further, in the planar biosensor, the working electrode and the counter electrode can be arranged on one of the pair of flat plate-like base materials. The state in which blood moves to the working electrode and the counter electrode by capillary action through the material can be visually confirmed.

  However, when a mark is printed on a transparent base material, it is difficult to visually confirm the state of blood movement below the mark. Therefore, it has not been possible to easily visually confirm both the position of the opening for introducing blood and the situation in which the blood moves.

  The present invention has been made in view of the circumstances described above, and its purpose is to make it possible to specify the position of an opening for introducing a material, and to visually confirm how a sample is introduced into a sample space. It is to provide a possible biosensor.

  (1) The biosensor according to the present invention includes a first substrate, a spacer that is stacked on the first substrate, and that forms a sample space that is open at the periphery of the first substrate, and the first sensor through the spacer. A translucent second substrate laminated on one substrate and the first substrate or the second substrate and the spacer, and at least a part of the translucency exposed to the sample space. The first electrode or the second electrode and the second substrate in a region corresponding to the sample space on the surface of the first substrate on which the spacer is stacked. The mark which can be visually recognized through is attached.

  Here, the biosensor in the present invention is electrically connected to a specific measuring device, and generates an electron serving as an electrical signal based on a biological sample typified by blood, plasma, urine, sweat, saliva and the like. Is.

  For example, blood is used as the biological sample. Blood components to be measured mainly include blood sugar, but other than blood sugar, for example, cortisol, cholesterol, neutral fat, hemoglobin, bilirubin, and trace metals such as copper, zinc and iron.

  The biosensor is used by being mounted on, for example, a blood component measurement device. Blood, which is a sample, is introduced into the sample space. When blood sugar, that is, glucose is measured as a blood component, glucose in the blood is specifically decomposed by an enzyme such as GOD or GDH fixed to the second electrode, for example. Electrons are generated during the decomposition of glucose. Due to the movement of the generated electrons, a current is generated between the first electrode and the second electrode. Based on this current value, the blood component measuring device calculates and displays the concentration of the blood component.

  Since the introduced blood can be visually recognized from the outside, it can be visually determined whether or not a sufficient amount of blood has been introduced into the sample space. In addition, since the mark is attached to the region corresponding to the sample space on the surface on which the spacer of the first substrate is laminated, the mark is the first electrode or the first electrode when blood is not introduced into the sample space. It can be visually recognized from the outside through the two electrodes and the second substrate. As blood is introduced into the sample space, the mark is obstructed by the blood and cannot be visually recognized, and the state of blood being introduced into the sample space can be more easily confirmed. In the present invention, “transmission” means that visible light passes through the inside of the substance without being substantially reflected or absorbed.

  (2) In the biosensor according to the present invention, the mark may indicate a position where the sample space opens at the periphery of the first substrate.

  The mark is, for example, a figure such as an arrow or a triangle indicating the position where the sample space is opened, and is provided in the vicinity of the position where the sample space is opened. Thereby, the position for introducing blood can be easily confirmed.

  (3) In the biosensor according to the present invention, a plurality of the marks may be arranged along a direction in which the sample flows from the opening.

  Since the marks are arranged along the direction in which the sample flows from the opening, as the blood is introduced, the marks in the vicinity of the opening cannot be seen in order. Based on the number of marks that are no longer visible, the amount of blood introduced into the sample space is generally understood. Since all marks cannot be seen, it can be determined that a sufficient amount of blood has been introduced into the sample space.

  (4) In the biosensor according to the present invention, each of the first substrate, the spacer, and the second substrate is an elongated thin flat plate, and the sample space is a circumferential edge of the first substrate. And may be extended along the longitudinal direction.

  The plate-shaped biosensor is easily held between human fingers, and the risk of falling is avoided. Since the sample space is opened at the peripheral edge in the short direction of the first substrate, it is easy to bring the opening on the distal end side into contact with blood while holding the vicinity of the proximal end in the longitudinal direction when blood is introduced. Done.

  (5) In the biosensor according to the present invention, a through-hole penetrating in the thickness direction is provided at an end of the second substrate corresponding to the sample space on the opposite side of the peripheral edge of the other substrate. It may be a thing.

  When the opening is brought into contact with blood, blood is introduced into the sample space by capillary action. The air that has filled the sample space is discharged to the outside through the through hole. Thereby, blood can be easily introduced.

  According to the biosensor of the present invention, each of the first electrode and the second electrode has translucency, and one of the first substrate and the second substrate has the first electrode or the second electrode and the translucency. Since the mark is visible through the other substrate having the property, the position of the sample suction port 21 for introducing the sample can be specified, and the state in which the sample is introduced into the sample space is marked. It can be confirmed by visual inspection without being obstructed.

FIG. 1 is a perspective view of a biosensor 10 according to an embodiment of the present invention as viewed from the second substrate 17 side. FIG. 2 is a perspective view of the biosensor 10 according to the embodiment of the present invention as viewed from the first substrate 11 side. FIG. 3 is a perspective view showing the configuration of the biosensor 10 according to the embodiment of the present invention. FIG. 4 is an enlarged view of the periphery of the sample space 23 before blood introduction. FIG. 5 is an enlarged view of the periphery of the sample space 23 into which blood is introduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. Note that the embodiment described below is merely an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention.

[Outline of Biosensor 10]
As shown in FIGS. 1, 2, and 3, the biosensor 10 includes a first substrate 11, a first electrode 12, a second electrode 13, a third electrode 14, a fourth electrode 15, and a spacer. 16 and the second substrate 17. These are laminated in the up-down direction 101 in the order of the second substrate 17, the spacer 16, each electrode, and the first substrate 11 in order from the upper side. However, a region (intermittent portion 20) where some spacers 16 do not exist exists above the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15, and the first electrode 12, A sample space 23 and the like are formed by the two electrodes 13, the third electrode 14, the fourth electrode 15, and the intermittent portion 20. The sample space 23 is an internal space into which blood as a sample is introduced, and is continuous with the external space through the sample suction port 21 and the air hole 22. The first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are disposed on the first substrate 11, respectively. On top of this, the first substrate 11 is bonded to the second substrate 17 via spacers 16. Here, the sample inlet 21 and the air hole 22 correspond to the opening and the through hole in the present invention, respectively. In the present embodiment, the vertical direction shown in FIGS. 1 and 2 is referred to as the vertical direction 101, the longitudinal direction of the biosensor 10 is referred to as the longitudinal direction 102, and the short direction of the biosensor 10 is short. This is referred to as direction 103. Further, the end of the longitudinal direction 102 where the sample inlet 21 is opened is referred to as the distal end side of the biosensor 10, and the opposite end is referred to as the proximal end side of the biosensor 10.

[First substrate 11]
The first substrate 11 is a rectangular flat plate made of an electrically insulating material. Each dimension of the first substrate 11 can be appropriately determined by those skilled in the art. As an example, the dimension in the longitudinal direction 102 and the lateral direction 103 of the first substrate 11, that is, the long side of the rectangle and the length of the short side The lengths are about 3 cm and about 1 cm, respectively. The dimension of the first substrate 11 in the vertical direction 101, that is, the thickness of the flat plate is about 2 mm. A first electrode 12, a second electrode 13, a third electrode 14, and a fourth electrode 15 are laminated on one surface of the first substrate 11. Examples of the electrically insulating material include polyesters such as polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA), fluororesin, and polycarbonate. Spacers 16 are stacked on the first substrate 11 with these electrodes in between, and the opposite surface is exposed to the external space. The dimensions of the first substrate 11 in the longitudinal direction 102 and the transverse direction 103 are the same as the dimensions of the second substrate 17 in the longitudinal direction 102 and the transverse direction 103. Here, the surface of the first substrate 11 on which the electrodes are laminated is referred to as an inner surface of the first substrate 11, and the opposite surface is referred to as an outer surface of the first substrate 11.

  For example, three marks 18 are arranged along the longitudinal direction 102 at positions corresponding to the intermittent portions 20 on the first substrate 11. The intermittent portion 20 extends about 1 cm from the distal end of the biosensor 10 toward the proximal end side, and has an extension of about 3 mm around the center in the short direction 103. The mark 18 is for indicating the position of the sample suction port 21. For example, a triangle or an arrow is selected as the shape. By arranging the mark 18 so that one of the corners of the triangle forming the mark 18 and the tip of the arrow are directed toward the sample suction port 21, the position of the sample suction port 21 can be easily determined. The mark 18 is, for example, part of the material of the first substrate 11 colored with a paint or the like, and is generally attached to the first substrate 11 by printing. The mark 18 is disposed on the inner surface of the first substrate 11, and the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are arranged on the first substrate 11 after the mark 18 is disposed. Is laminated. As the color of the first substrate 11, for example, white is selected as a color in which the mark 18 and the introduced blood are easily confirmed.

[First electrode 12, second electrode 13, third electrode 14, fourth electrode 15]
Each of the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 is a transparent electrode having translucency. Examples of materials for the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 include, for example, an indium tin oxide mixture, zinc oxide, tin oxide, silver, an indium zinc-based mixture, and a titanium oxide-based mixture. Etc. Such a transparent electrode can be formed on the 1st board | substrate 11 with which the mark 18 was printed, for example by methods, such as a screen printing method, an inkjet method, sputtering, vacuum evaporation, a sol gel method, cluster beam evaporation, or PLD. The first substrate 11 is provided with contacts 19A, 19B, 19C, and 19D made of conductive metal. The contacts 19 </ b> A, 19 </ b> B, 19 </ b> C, and 19 </ b> D are disposed around the base end side of the first substrate 11 so as to penetrate the first substrate 11 in the vertical direction 101. One ends of the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are located on the contacts 19A, 19B, 19C, and 19D exposed from the inner surface of the first substrate 11, respectively. The contacts 19A, 19B, 19C, 19D are electrically connected. The contacts 19A, 19B, 19C, and 19D exposed from the outer surface of the first substrate 11 are electrically connected to terminals provided in a blood component measuring device described later. That is, the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are electrically connected to the blood component measuring device via the contacts 19A, 19B, 19C, and 19D, respectively.

  FIG. 4 shows an enlarged view of the periphery of the sample space 23 before blood introduction. The first electrode 12 and the second electrode 13 each extend in the longitudinal direction 102 in the first substrate 11, and have a key-like portion protruding inward in the lateral direction 103 near the tip of the electrode. Two key-like portions are provided for the first electrode 12 and one for the second electrode 13. The respective key-like portions are arranged to face the inner side in the short direction 103, and the key-like portion of the second electrode 13 is located between the two key-like portions of the first electrode 12 in the longitudinal direction 102. . At that time, the distal ends of the key-shaped portions of the second electrode 13 are located on the first electrode 12 side in the lateral direction 103 relative to the distal ends of the two key-shaped portions of the first electrode 12. That is, the first electrode 12 and the second electrode 13 are disposed so that the respective key-like portions are engaged with each other. A gap having a predetermined interval is interposed between the first electrode 12 and the second electrode 13. Each key-like part is arranged at a position corresponding to the intermittent part 20. The proximal ends of the first electrode 12 and the second electrode 13 are electrically connected to the aforementioned contacts 19A and 19B, respectively. When the biosensor 10 is used, the blood introduced into the sample space 23 contacts the first electrode 12 and the second electrode 13 across the gap interposed between both electrodes.

  An enzyme that decomposes glucose in blood as a sample is immobilized on the key-shaped portion of the second electrode 13. Examples of this enzyme include GOD and GDH. In addition to these enzymes, coenzymes and electron mediators may be immobilized on the second electrode 13. Examples of such coenzymes include pyrroloquinoline quinone, nicotinamide adenine dinucleotide, flavin adenine dinucleotide, and nicotinamide adenine dinucleotide phosphate that function as electron carriers. Moreover, as an electron mediator, the compound containing transition metals, such as ruthenium, osmium, molybdenum, tungsten, iron, cobalt, is mentioned, for example. The immobilization of these enzymes and the like is realized by applying a solution containing the enzymes and the like to the second electrode 13 and drying it.

  The third electrode 14 and the fourth electrode 15 are used by the blood component measurement device to determine whether or not a sufficient amount of blood has been introduced into the sample space 23. The third electrode 14 and the fourth electrode 15 extend slightly from the central position in the longitudinal direction 102 with respect to the key portions of the first electrode 12 and the second electrode 13, and the other ends are electrically connected to the contacts 19C and 19D. It is connected to the. The third electrode 14 and the fourth electrode 15 are juxtaposed inside the first electrode 12 and the second electrode 13 in the lateral direction 103, respectively. Since the introduced blood enters from the sample inlet 21 toward the base end side of the biosensor 10, the blood contacts the first electrode 12 and the second electrode 13, and then the third electrode 14 and the fourth electrode. 15 is contacted. Since the blood component measuring apparatus determines that a sufficient amount of blood has been introduced into the sample space 23 based on the contact of the blood with the third electrode 14 and the fourth electrode 15, the blood reliably After the contact with the second electrode 13, the process of calculating the concentration of the blood component and the like can be started.

[Spacer 16]
The spacer 16 is a flat plate member interposed between the first substrate 11 and the second substrate 17. For the spacer 16, a double-sided tape, an adhesive, or the like is used, and a light-transmitting material is preferably used. The spacer 16 does not necessarily have translucency, but the spacer 16 has translucency so that the entire inner surface of the first substrate 11 can be visually recognized from the second substrate 17 side of the biosensor 10. Become. Therefore, in addition to the marks 18, marks, symbols, and characters that can be visually recognized from the outside can be written on the inner surface of the first substrate 11. The dimensions of the spacer 16 in the longitudinal direction 102 and the transverse direction 103 are the same as those of the first substrate 11, and the dimension in the vertical direction 101, that is, the thickness of the spacer 16 is about 0.1 mm. As shown in FIG. 3, the spacer 16 has an intermittent portion 20. As described above, the intermittent portion 20 extends about 1 cm from the distal end of the biosensor 10 toward the proximal end side, and has an extension of about 3 mm around the center in the lateral direction 103. That is, the spacer 16 has a substantially concave shape in which a part of a rectangular flat plate is cut off by the intermittent portion 20. A space between the first substrate 11 and the second substrate 17 constituted by the intermittent portion 20 is referred to as a sample space 23 in the present embodiment. However, each dimension of the spacer 16 is not limited to this, and may be any dimension suitable for blood that has contacted the sample inlet 21 to be introduced into the sample space 23 by capillary action. The periphery of the tips of the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 is located in the intermittent portion 20 and exposed to the sample space 23.

[Second substrate 17]
For the second substrate 17, for example, polyethylene terephthalate is suitably used as a light-transmitting material. As described above, the shape and dimensions of the second substrate 17 are the same as those of the first substrate 11. The second substrate 17 is provided with an air hole 22 penetrating the second substrate 17 in the vertical direction 101. The air hole 22 is continuous with the sample space 23 and the external space. When air is introduced, the air filled in the sample space 23 is released to the external space. Since the blood introduced into the sample space 23 is filled between the sample inlet 21 and the air hole 22, the air hole 22 is connected to the third electrode 14 and the air in order to make sure that the blood contacts all the electrodes. It is necessary to be provided around the distal end of the fourth electrode 15 or on the proximal end side.

[Blood component measuring device]
A blood component measuring device not shown in the figure calculates and displays the concentration of blood components and the like (blood glucose level when measuring blood glucose) based on the current generated by the chemical change of the blood component. The blood component measuring device is provided with a sensor insertion port into which the biosensor 10 can be inserted, and the inserted biosensor 10 is electrically connected to the blood component measuring device via the contacts 19A, 19B, 19C, 19D. . The blood component measurement device calculates and displays the concentration of the blood component based on the current input from the biosensor 10. The blood component measurement device includes an operation button for receiving an operation and a display screen for displaying necessary information. The operator can start measurement of blood components or display the calculated concentration of blood components on the display screen by performing an operation with the operation button while checking the information displayed on the display screen. . In addition, the blood component measuring apparatus may include a nonvolatile memory or a clock for storing the calculated blood component concentration and the like in time series. The size and shape of the blood component measuring device are selected by those skilled in the art. For example, assuming that a diabetic patient always carries a blood component measurement device and performs measurement regularly or irregularly, the blood component measurement device may be configured to have a portable size.

[How to use biosensor 10]

  Hereinafter, a method of using the biosensor 10 will be described with reference to the drawings as appropriate.

  First, a diabetic patient inserts, in the longitudinal direction 102, the end opposite to the side where the sample inlet 21 is opened into the blood component measuring device. Thereby, the 1st electrode 12, the 2nd electrode 13, the 3rd electrode 14, and the 4th electrode 15 are electrically connected with a blood component measuring device via contacts 19A, 19B, 19C, and 19D, respectively.

  Diabetic patients pierce their palms with a needle to exude blood. A diabetic patient holds a blood component measuring device and makes the sample inlet 21 of the biosensor 10 contact the exuded blood. At this time, the diabetic patient can visually confirm the position of the sample inlet 21 by confirming the mark 18 on the first substrate 11.

  The blood that has contacted the sample inlet 21 enters the sample space 23 from the sample inlet 21 by capillary action. The air that has filled the sample space 23 is discharged from the air hole 22 to the outside. The diabetic patient can visually confirm how blood is introduced into the sample space 23 through the second substrate 17. As the sample space 23 is filled with blood, the marks 18 cannot be confirmed in order from the one on the sample suction port 21 side. When all three marks 18 cannot be confirmed, the diabetic patient determines that a sufficient amount of blood has been introduced into the sample space 23.

  FIG. 5 shows an enlarged view of the periphery of the sample space 23 into which blood is introduced. The blood 31 has entered the vicinity of the air hole 22 in the sample space 23 by capillary action. In this state, the three marks 18 are blocked by the blood 31 and are not visually recognized. The blood 31 is in contact with all of the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15.

  In order to determine whether or not blood has been introduced into the sample space 23, a constant voltage is applied between the third electrode 14 and the fourth electrode 15 by the blood component measuring device. When a sufficient amount of blood is introduced into the sample space 23, a minute current flows through the blood component measuring device via the blood interposed between the third electrode 14 and the fourth electrode 15. When this current exceeds the threshold value, the blood component measurement device determines that a sufficient amount of blood has been introduced into the sample space 23. When a sufficient amount of blood has been introduced into the sample space 23, the blood component measurement device automatically starts calculating the glucose concentration and the like. If the blood component measuring apparatus does not have a function of automatically determining the introduction of blood, calculation of the glucose concentration or the like may be started by receiving an input from a diabetic patient.

  When the calculation of the glucose concentration is started, the blood component measurement device applies a constant voltage between the first electrode 12 and the second electrode 13. In the sample space 23, glucose contained in blood is specifically decomposed by GOD or GDH fixed to the second electrode 13. Free electrons generated by the decomposition of glucose move between the first electrode 12 and the second electrode 13 due to the influence of voltage, and a current flows. This current is detected by the substrate of the blood component measurement device through the contacts 19A and 19B, and the amount of glucose contained in the blood is calculated.

[Operational effects of this embodiment]

  According to the biosensor 10 according to the present embodiment, the mark 18 is disposed on the first substrate 11, and the second substrate 17, the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are respectively provided. Since it has translucency, the mark 18 becomes visible through the first electrode 12 and the second substrate 17 (or the second electrode 13 and the second substrate 17). Accordingly, the position of the sample inlet 21 for introducing the sample can be specified, and the state of blood being introduced into the sample space 23 can be visually confirmed without being blocked by the mark 18.

  Further, since the mark 18 is arranged along the longitudinal direction 102, the amount of blood introduced into the sample space 23 can be roughly determined by the number of the marks 18 that cannot be confirmed from the outside. Since it becomes impossible to confirm, it can be determined that a sufficient amount of blood has been introduced into the sample space 23.

  Further, since the sample space 23 is continuous with the external space by the sample suction port 21 and the air hole 22, blood is easily introduced by capillary action when blood is brought into contact with the sample suction port 21. .

  In addition, since the biosensor 10 includes the third electrode 14 and the fourth electrode 15, the blood component measurement device can determine whether or not a sufficient amount of blood has been introduced into the sample space 23. As a result, it is possible to prevent a diabetes patient from operating mistakes or malfunction of the device, or to control for automating the start of measurement.

[Modification]
Hereafter, it supplements about the modification of this invention. First, in the present embodiment, the first electrode 12, the second electrode 13, the third electrode 14, the fourth electrode 15, and the second substrate 17 do not have to be completely transparent, and the second substrate of the biosensor 10 is not necessary. It is sufficient that the sample space 23 and the mark 18 have translucency so that they can be visually recognized from the 17th side. Therefore, the first electrode 12, the second electrode 13, the third electrode 14, the fourth electrode 15, and the second substrate 17 may have a translucent color. The first electrode 12, the second electrode 13, the third electrode 14, the fourth electrode 15, and the second substrate 17 need only have translucency at positions corresponding to the sample space 23, and are not necessarily the whole. It is not necessary to have translucency.

  In the present embodiment, the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are directly connected to the contacts 19A, 19B, 19C, and 19D, respectively. The contacts 19A, 19B, 19C, and 19D may be connected to each other through a metallic lead wire or the like disposed on one substrate 11.

  In this embodiment, the mark 18 is a triangle, and three marks 18 are provided along the longitudinal direction 102. However, these marks may be other figures suitable for showing the sample suction port 21. The number is not limited to three. For example, the mark 18 is an arrow extending along the longitudinal direction 102, and the mark 18 may have a scale that can determine the distance that blood has entered.

  In the present embodiment, the sample inlet 21 is provided on the distal end side of the biosensor 10, but the sample inlet 21 is not necessarily provided on the distal end side. That is, it may be opened at the side edge of the biosensor 10. Accordingly, the position and shape of the sample space 23 are also appropriately changed. A spacer 16 having an optimal shape for forming such a sample space 23 is selected. Further, the arrangement and shape of the first electrode 12, the second electrode 13, the third electrode 14, the fourth electrode 15, and the mark 18 are also appropriately changed according to the sample space 23.

  In the present embodiment, the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 are stacked on the first substrate 11, but the first electrode 12, the second electrode 13, The third electrode 14 and the fourth electrode 15 may be stacked on the surface of the second substrate 17 on the spacer 16 side. At this time, the first electrode 12, the second electrode 13, the third electrode 14, and the fourth electrode 15 may be stacked so as to bypass the air hole 22 opened in the second substrate 17. The contacts 19A, 19B, 19C, 19D are respectively provided on the second substrate 17 and exposed on the surface opposite to the spacer 16. Also in the present embodiment, the mark 18 is visible through the first electrode 12 and the second substrate 17 (or the second electrode 13 and the second substrate 17).

DESCRIPTION OF SYMBOLS 10 ... Biosensor 11 ... 1st board | substrate 12 ... 1st electrode 13 ... 2nd electrode 16 ... Spacer 17 ... 2nd board | substrate 18 ... Mark 21 ... Sample inhalation Mouth (opening)
22 ... Air hole (through hole)
23 ... Sample space

Claims (5)

A first substrate;
A spacer that is stacked on the first substrate to form a sample space that is open at the periphery of the first substrate;
A second substrate having translucency laminated on the first substrate through the spacer;
A first electrode and a second electrode that are laminated between the first substrate or the second substrate and the spacer and have a light-transmitting property at least partially exposed to the sample space;
A biosensor in which a region corresponding to the sample space on the surface of the first substrate on which the spacers are stacked is marked through the first electrode or the second electrode and the second substrate.   2. The biosensor according to claim 1, wherein the mark indicates a position where the sample space opens at a peripheral edge of the first substrate.   The biosensor according to claim 2, wherein a plurality of the marks are arranged along a direction in which a sample flows from the opening.   Each of the first substrate, the spacer, and the second substrate is an elongated thin flat plate, and the sample space is opened at a peripheral edge in the short direction of the first substrate, and extends along the longitudinal direction. The biosensor according to any one of claims 1 to 3, wherein the biosensor is extended.   5. The through-hole penetrating in the thickness direction is provided at an end of the second substrate corresponding to the sample space on the opposite side of the peripheral edge of the other substrate. Biosensor.

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