JPH0714876Y2 - Mechanism of attachment of diffusion limiting membrane in biosensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a diffusion limiting membrane attachment mechanism in a biosensor, and more specifically, dropping body fluid onto a physiologically active substance-immobilized membrane on which a physiologically active substance is immobilized, In a biosensor that measures the amount of a specific substance in a body fluid by detecting the amount of the substance that is produced or disappeared in the presence of a physiologically active substance, a state in which the body fluid is dropped to bring it into contact with an electrode The present invention relates to a novel diffusion limiting membrane attachment mechanism for performing the above.

<Problems to be solved by conventional technology and device> Focusing on the characteristic that it is possible to detect extremely complicated organic compounds, proteins, etc. from the past with extremely high sensitivity and selectively, Research and development have been carried out for measuring the above-mentioned organic compounds, proteins and the like with a biosensor having a physiologically active substance immobilized on the surface of.

In particular, in the case of biochemical analysis of body fluid components for clinical examinations and prevention of diseases, the biosensors described above are optimal, and research and development are being carried out more enthusiastically.

A glucose sensor for measuring glucose concentration will be described as an example. As shown in FIG. 6, an electrode body (72) is provided at a predetermined position of a base (71) and is pressed against the electrode body (72). The electrode body (7
2) is kept in a wet state, and a wetting liquid holding section (not shown) for keeping the active state is provided. The electrode body (72) includes a base electrode (73), an immobilized glucose oxidase film (hereinafter referred to as an immobilized GOD film) (74) covering the base electrode (73), and an immobilized GOD film. And a diffusion limiting film (75) that covers (74).

Therefore, when the glucose concentration is not measured, the wet state of the electrode main body (72) is maintained and fixed by pressing the wetting liquid holding unit against the electrode main body (72).
It maintains the activity of the GOD membrane (74) and maintains a state in which accurate glucose concentration measurement can be performed. Then, when the glucose concentration is measured, the pressure contact state of the wetting liquid holding portion with respect to the electrode body portion (72) is released, and the diffusion limiting film (7
5) The body fluid to be measured, for example, blood, may be dropped onto the surface of 5), large particles such as blood cells are prevented from entering, and only small particles reach the immobilized GOD membrane (74). Of the small particles that have reached the immobilized GOD membrane (74), glucose undergoes an enzymatic reaction in the presence of glucose oxidase (hereinafter abbreviated as GOD) and oxygen to produce gluconic acid and hydrogen peroxide. . Therefore, by extracting an electric signal corresponding to the amount of hydrogen peroxide through the base electrode (73), the glucose concentration in blood can be accurately measured.

However, in the case of sequentially measuring the glucose concentration in the blood of a large number of people, it is not only necessary to drop the blood on the diffusion limiting film (75) each time the measurement operation is performed, but also the measurement operation is performed. Therefore, it is necessary to prevent the decrease in glucose permeability by replacing the diffusion limiting membrane (75) in which clogging has occurred. And these tasks are
This involves replacement work of the diffusion limiting film (75) integrally attached to the electrode body (72), and moreover, the diffusion limiting film (75) is immobilized on the GOD film (74). Since it is necessary to make the mounting state uniform with respect to, the work time is not only long, but also there is some variation in the mounting state, so the measurement results vary.

Further, in order to solve such a problem, a diffusion limiting film is adhered to a diffusion limiting film holding plate, and the diffusion limiting film holding is fixed in a state of having a predetermined relative positional relationship with the electrode. It is conceivable to adopt a structure in which the diffusion limiting film holding plate is mounted on the plate mounting member, but even if such a structure is adopted, the pressure contact state of the diffusion limiting film holding plate to the electrode surface is said to be uniform. There is no guarantee, and there is the problem that the measurement results will vary considerably (for example, variation of about 4%).

Further, when the above configuration is adopted, when the diffusion limiting film holding plate is attached or removed, the immobilized GOD film provided on the electrode surface is inevitably rubbed,
There is also a problem that the activity of the immobilized GOD membrane as a whole is lowered, and in the worst case, the immobilized GOD membrane is damaged.

Although the above description has been made only for the case of measuring the glucose concentration, the same applies to the case of measuring the concentration of other substances in blood, the case of measuring the concentration of substances contained in urine other than blood, etc. Problems can occur.

<Purpose of Invention> This invention was made in view of the above problems,
Provided is a mechanism for attaching a diffusion limiting film in a biosensor, which can make the pressed state of the diffusion limiting film against the electrode uniform and can keep the physiological activity of the immobilized physiologically active substance film provided on the electrode surface high. Is intended.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the diffusion limiting membrane attachment mechanism in the biosensor of the present invention has an electrode for measuring body fluid, which is provided at a predetermined position of the casing, and accommodates the electrode. And a diffusion limiting film holding plate mounting member provided at a predetermined position of the casing so that the through hole and the diffusion limiting film holding plate can be accommodated, and the electrode can be moved toward and away from the diffusion limiting film holding plate. A positioning portion provided at a predetermined position of the casing for positioning the membrane holding plate mounting member at a position moved by a predetermined distance in a direction away from the electrode or a position moved by a predetermined distance in a direction in which the electrode approaches. ing.

However, it is preferable that the diffusion limiting film holding plate mounting member is rotatably provided with one end as a fulcrum, and particularly, as the diffusion limiting film holding plate mounting member,
More preferably, the diffusion limiting film holding plate can be accommodated in the groove or taken out from the groove only by sliding the diffusion limiting film holding plate.

Further, the positioning portion is a swing member having a guide groove that engages with an engagement shaft provided in the diffusion limiting film holding plate mounting member, and the guide groove is located in line with the swing center. It is preferable to have a pair of engaging portions, and in this case, the diffusion limiting film holding plate, which is positioned by the positioning portion and has moved a predetermined distance in the direction of approaching the electrode, is mounted on the surface of the electrode. It is sufficient that the position is moved by a predetermined distance in the direction away from the electrode and is moved by a predetermined distance in the direction away from the electrode. The diffusion limiting film holding plate to which the above position is attached may be set so as not to be in contact with the surface of the electrode.

<Operation> In the diffusion limiting membrane mounting mechanism having the above configuration, the body fluid measurement electrode provided at the predetermined position of the casing, the through hole capable of accommodating the electrode, and the groove capable of accommodating the diffusion limiting membrane holding plate are provided. The diffusion limiting film holding plate mounting member provided at a predetermined position of the casing so as to be capable of reciprocating so as to approach and separate from the electrode, and the diffusion limiting film holding plate mounting member by a predetermined distance in the direction of separating from the electrode. The diffusion limiting film holding plate mounting member is positioned because it has a positioning portion provided at a predetermined position of the casing for positioning at the moved position or the position moved by a predetermined distance in the approaching direction of the electrode. By attaching the diffusion limiting film holding plate to which the diffusion limiting film is adhered in a state where the portion is positioned at a position moved by a predetermined distance in a direction away from the electrode,
It is possible to reliably prevent the rubbing force from acting on the electrodes. Then, if the diffusion limiting film holding plate mounting member having the diffusion limiting film holding plate mounted thereon is moved in a direction approaching the electrode and positioned by the positioning portion, the diffusion limiting film holding plate can be pressed against the electrode. The pressure contact state in this case can be uniformly set based on the position which is positioned by the positioning portion and which is moved by a predetermined distance in the direction approaching the electrode, and the diffusion limiting film holding plate is pressed against the electrode. In this case, it is possible to reliably prevent the rubbing force from acting.

When the diffusion limiting film holding plate mounting member is rotatably provided with one end as a fulcrum, it is sufficient to apply a moving force to an arbitrary portion of the diffusion limiting film holding plate mounting member. A smooth turning operation can be performed.

In these cases, if the diffusion limiting film holding plate mounting member is such that the diffusion limiting film holding plate can be accommodated in the groove or taken out from the groove only by sliding the diffusion limiting film holding plate, the diffusion limiting film holding plate can be removed. The film holding plate can be accurately positioned with respect to the diffusion limiting film holding plate mounting member, and the mounting operation and the removing operation can be easily performed.

Further, the positioning portion is a rocking member having a guide groove that engages with an engagement shaft provided on the diffusion limiting film holding plate mounting member, and the guide groove is positioned in line with the rocking center. In the case of having a pair of engaging portions, the engaging shaft moves due to the moving force applied to the diffusion limiting film holding plate mounting member, and the swinging member swings. Is positioned while being engaged with one of the engaging portions. Then, when a force in the same direction as the above-mentioned moving force is applied and then a moving force in the opposite direction is applied, first, the engagement between the engaging shaft and one of the engaging portions is disengaged, and the swinging member. The engaging shaft moves while swinging, and is finally positioned in a state of being engaged with the other engaging portion. Since the diffusion limiting film holding plate mounting member moves in conjunction with the engagement shaft, the diffusion limiting film holding plate mounting member is also positioned at the corresponding position.

Further, as long as the position, which is moved by a predetermined distance in the direction approaching the electrode, which is positioned by the positioning portion, is set so that the mounted diffusion limiting film holding plate can be pressed against the surface of the electrode, the same as above. The action of can be achieved.

Further, if the position, which is positioned by the positioning unit and is moved by a predetermined distance in the direction away from the electrode, is set so that the mounted diffusion limiting film holding plate is not in contact with the surface of the electrode. The same operation as above can be achieved.

<Examples> Hereinafter, detailed description will be given with reference to the accompanying drawings illustrating examples.

FIG. 5 is a schematic perspective view showing a blood glucose level measuring device, in which a display part (11) and an operation switch (12) are provided at a predetermined position of a casing (1) and an external cover (2) which can be opened and closed. Is provided. The enzyme electrode (3), the diffusion limiting membrane holding plate mounting member (32), and the inner cover (5) are provided corresponding to the outer cover (2).

This will be described in more detail with reference to FIG. 1 showing the main part of FIG.

Enzyme electrode (3) attached to the casing (1)
Has a base electrode (not shown) and a fixed GOD film (31) covering the base electrode, and
The upper surface is formed to be an arcuate convex surface. And
The diffusion limiting film holding plate mounting member (32) has a through hole (33) through which the enzyme electrode (3) can be inserted, and a diffusion limiting film holding plate (4) described later at a predetermined position on the upper surface.
An upper flange that has a diffusion limiting film holding plate accommodating groove (34) of the same width as that of the diffusion limiting film retaining plate accommodating plate (34) and that protrudes in a direction slightly closer to the through hole (33) slightly above the diffusion limiting film retaining plate accommodating groove (34). (35) and an inner cover positioning protrusion (39) protruding from a predetermined position on the upper side of the opening of the diffusion limiting film holding plate accommodating groove (34). Further, the diffusion limiting film holding plate accommodating groove (34) has an engaging protrusion (36) at a predetermined position and a hole (37) penetrating in the vertical direction. Further, the diffusion limiting film holding plate mounting member (32) is wholly connected to the casing (1) by a shaft (38) so that the diffusion limiting film holding plate mounting member (32) can be vertically rotated by a positioning mechanism (13) described later. It is regulated. The casing (1)
(30) between the diffusion limiting film holding plate mounting member (32)
Is inserted to constantly bias the diffusion limiting film holding plate mounting member (32) upward. Further, at a predetermined position of the casing (1), there is provided a retaining shaft (15) protruding upward through the hole (37) in the downward rotating state.

The inner cover (5) slidably and rotatably engages with a guide groove (52) formed in a predetermined range near the shaft (38) of the diffusion limiting film holding plate mounting member (32). It has a pair of inward projections (51) and a shaft (3
It has a large diameter hole (53) facing the through hole (33) at a position farthest from the position (8). Further, the downward projection (54) is provided on the lower surface of the end portion parallel to the sliding direction, and the downward projection (55) engaging with the internal cover positioning projection (39) is provided at a predetermined position closer to the inside. Have

The outer cover (2) is rotatably attached to the casing (1) by a shaft (21) at an end on the guide groove (52) side, and has a predetermined end of the casing (1) at the other end. An engagement portion (22) for holding a closed state in which the slide engagement portion (14) provided at the position is engaged is provided. And
A wetting liquid storage tank (23) is detachably attached to a predetermined position on the lower surface of the outer cover (2), and an opening (24) facing the enzyme electrode (3) in a closed state is formed so as to project. Moreover, the sponge (2
5) is housed. Further, a downward flange (26) is formed at an end portion of the outer cover (2) adjacent to the shaft (21), and the outer cover (2) is rotatably connected to the downward flange (26) by a shaft (27). The tip of the link (28) is engaged with the inward projection (51). Incidentally, (29) is an inward projection formed at a predetermined position of the casing (1), and engages with a predetermined position near the base of the inner cover (5) which moves following the operation of opening the outer cover (2). Then, the inner cover (5) is brought into pressure contact with the diffusion limiting film holding plate mounting member (32).

The diffusion limiting film holding plate (4), as shown in FIG.
An opening (41) facing the enzyme electrode (3) in the mounted state is formed at a predetermined position of a long plate whose short side is formed in an arc shape, and the engaging projection (36) and hole (37) are formed. ), Openings (42) and (43) facing each other are formed, and the openings (41) are covered with a diffusion limiting film (44). In addition, the engaging protrusion (3
Form a downward protrusion (45) at the center of the end on the 6) side,
The diffusion limiting film holding plate (4) can be easily gripped regardless of the surface on which the diffusion limiting film holding plate is placed.

2A is a vertical cross-sectional view of a main part of the positioning mechanism, and FIG. 2B is a partially transparent bottom view of FIG. 2C to 2F are enlarged views showing the operation of the positioning mechanism.

The diffusion limiting film holding plate mounting member (32) has a flange (61) on the lower surface of the tip portion, and an engaging shaft (62) extending toward the shaft (38) at a predetermined position below the flange (61). )have. Then, a lever (64) capable of horizontally rotating around the shaft (63) is provided at a predetermined position of the casing (1), and the lever (64) rotates toward the side away from the shaft (38). A biasing spring (65) is provided. Further, the lever (64) has an endless groove (66) which engages with the engaging shaft (62) in the center thereof, and the upper part of the lever (64) follows the vertical movement of the engaging shaft (62). A swing member (67) that swings around the shaft (67a) is provided. The groove (66) is located on a straight line with respect to the center of swing.
A diffusion limiting film having a pair of upward recesses (66a) (66b) and reaching an upper or lower rotation limit position in a state in which the engagement shaft (62) is engaged with any one of the recesses. Holding plate mounting member (32)
Is designed to rotate. Further, (68) is a rotating member exposed to the outside from the lower surface of the casing (1), and is in a state in which the lever (64) can be rotated by the spring (65), that is, the engaging shaft (62). The state where the engagement state with the groove (66) is maintained and the state where the rotation of the lever (64) by the spring (65) is blocked, that is, the engagement between the engagement shaft (62) and the groove (66) This is to select the state to be released.

The operation of the blood glucose level measuring device having the above configuration is as follows.

External cover (2) when blood glucose is not measured
It suffices that the engagement part (22) is engaged with the slide engagement part (14) to maintain the closed state,
The sponge (25) stored in the opening (24) of the wetting liquid storage tank (23) comes into contact with the enzyme electrode (3) to immobilize the immobilized GOD membrane (3).
1) is kept in a wet state and the immobilized GOD membrane (31) is retained without lowering its activity (see FIG. 3A). In this state, the engagement shaft (62) provided on the diffusion limiting film holding plate mounting member (32) is moved downward against the spring (30) and once engaged with the upward recess (66a). After that (see FIG. 2E), the engagement is in the disengaged state (see FIG. 2F). When the outer cover (2) is closed, the inner cover ( Since a force that substantially corresponds to the sliding direction of 5) is applied, the inner cover (5) can be slid smoothly.

When measuring blood glucose level, slide engaging part (14)
It is sufficient to slide the outer cover (2) by sliding, and the engagement shaft (62) moves upward together with the diffusion limiting film holding plate mounting member (32) by the spring (30), and the engagement shaft (62) moves upward. Accordingly, the swinging member (67) is swung as shown in FIG. 2D and is finally positioned in the state of being engaged with the upward recess (66b) (see FIG. 2C). In this state, after the diffusion limiting film holding plate (4) having blood dropped in the opening (41) is mounted on the diffusion limiting film holding plate mounting member (32), the diffusion limiting film holding plate mounting member (32) is springed ( The immobilized GOD membrane (31) and the diffusion limiting membrane (44) are brought into close contact with each other by rotating downward against the (30), and the operation switch (12) is operated in this state, whereby the enzyme electrode (3) Necessary processing is performed based on the electrical signal extracted from the display unit, and the blood glucose level is visually displayed on the display unit (11). Door can be.

More specifically, the diffusion limiting film holding plate mounting member (32) is pressed downward by the closing operation, and the engagement shaft (62) is released from the lower upward recess (66a). Since the engagement portion (22) and the slide engagement portion (14) are disengaged from each other (see FIG. 2F), the urging force of the spring (30) is generated. The diffusion limiting film holding plate mounting member (32), the inner cover (5), and the outer cover (2) are rotated upward to some extent (see FIG. 3B), and then the outer cover (2) can be freely moved. It can be rotated. When the outer cover (2) is rotated, the distal end of the link (28) is engaged with the inward projection (51), so that the rotation of itself is significantly suppressed. Is moved to the shaft (21) side, and as a result, the inner cover (5) is also moved to the shaft (21) side (see FIG. 3C). Since the inner cover (5) has only a pair of inward projections (51) engaged with the guide grooves (52), it may rotate upwards as it is, but the inward projections ( Since a downward force is exerted by engaging with 29), the downward protrusion (54) is pressed against the upper surface of the diffusion limiting film holding plate device portion (32), and the downward protrusion (55) is inside. The state of engaging with the cover positioning protrusion (39) can appear.

In this state, the diffusion limiting film holding plate (4) on which blood is dropped is inserted into the diffusion limiting film holding plate housing groove (34), and the opening (42) of the diffusion limiting film holding plate (4) is engaged with the engaging projection ( 36), and in this state, by applying a downward force to the inner cover (5), the inner cover (5) is rotated downward together with the diffusion limiting film holding plate mounting member (32), and the engaging shaft (62 ) Engages with the lower upward recess (66a) (second
(See FIG. E) As a result, the downward rotation state is maintained, and the diffusion limiting film (44) of the diffusion limiting film holding plate (4) is pressed against the immobilized GOD film (31) of the enzyme electrode (3). Can be secured. Further, the retaining shaft (15) protruding through the hole (37) engages with the opening (43), so that the diffusion limiting film holding plate (4) is prevented from being pulled out by force, and by extension, the fixing due to friction is performed. It is possible to prevent deterioration of the compound GOD film (31). Even when the diffusion limiting film holding plate (4) is attached, the immobilized GOD film (31) caused by friction
Can be prevented from deteriorating.

Therefore, the blood glucose level can be measured by operating the operation switch (12) in this state, and the measurement result can be visually displayed on the display unit (11).

After the measurement is completed, the engagement between the engagement shaft (62) and the downward concave portion (66a) may be released by applying a downward force to the inner cover (5) (Fig. 2F). If the downward force is released, the inner cover (5) and the diffusion limiting film holding plate mounting member (32) are rotated upward by the urging force of the spring (30), so the diffusion limiting film (44). And fixed GO
The pressed state with the D film (31) is released, and the engagement between the retaining shaft (15) and the opening (43) is released.

Therefore, the diffusion limiting film holding plate (4) can be pulled out without applying a frictional force to the fixed GOD film (31).

When the blood glucose level is measured again, blood may be dropped on a new diffusion limiting film holding plate (4) and the above series of operations may be performed.

And, as is clear from the above description, when the diffusion limiting film holding plate (4) is mounted on the diffusion limiting film holding plate mounting member (32), it is caused by the sliding of the inner cover (5). Since the large-diameter hole (53) is displaced from the position directly facing the enzyme electrode (3), it becomes almost impossible to touch the enzyme electrode (3) through the large-diameter hole (53). When it is necessary to focus attention on the pressing operation of the cover (5), the pressing operation of the operation switch (12), etc., a part of the body is inadvertently dropped on the blood dropped on the diffusion limiting film holding plate (4). It is possible to reliably prevent the inconvenience of touching. Of course, when the diffusion limiting film holding plate (4) is attached or detached, or when blood is dropped on the diffusion limiting film holding plate (4), the blood is exposed. Although some may be touched, there is little room for inattention to intervene because other operations are not performed while these operations are being performed.

Note that the present invention is not limited to the above-described embodiments, and can be applied to, for example, a device for measuring cholesterol, neutral fat, urea, etc., and a diffusion limiting film holding plate device member (32 ) Can be moved up and down while maintaining the horizontal state as a whole, and various design changes can be made within a range not changing the gist of the present invention.

<Effects of the Invention> As described above, the present invention provides the diffusion limiting film holding plate mounting member on which the diffusion limiting film holding plate is mounted so as to be movable in the direction of approaching and separating from the electrode, and the diffusion limiting film. Since the holding plate mounting member is provided with a positioning portion that positions the holding plate mounting member at a position that is moved a predetermined distance in the direction away from the electrode or at a position that is moved a predetermined distance in the direction approaching the electrode, it is By mounting the diffusion limiting film, it is possible to reliably prevent the sliding state between the electrode and the electrode, and maintain the activity of the physiologically active substance at a high level. By moving in the direction of approaching the electrode for a predetermined distance,
The pressure-contact state between the physiologically active substance-immobilizing membrane and the diffusion limiting membrane can be set in a preset state, and the practicable effect peculiar to the invention is that the variation in the measured values can be significantly suppressed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a diffusion limiting film mounting mechanism, FIG. 2A is a longitudinal sectional view of an essential part showing a positioning mechanism, and FIG. 2B is a partially transparent bottom view of FIG. 2C to F are enlarged views for explaining the operation of the positioning mechanism, FIG. 3 is a view for explaining the diffusion limiting film mounting operation, FIG. 4 is a schematic diagram showing the configuration of the diffusion limiting film holding plate, and FIG. FIG. 6 is a perspective view schematically showing a blood glucose level measuring device incorporating a diffusion limiting film attachment mechanism, and FIG. 6 is a schematic vertical sectional view showing a conventional example. (1) ... Casing, (2) ... Outer cover, (3) ... Enzyme electrode, (4) ... Diffusion limiting membrane holding plate, (5) ... Inner cover, (13) ... Positioning mechanism, (30) ... Spring, (32) ... Diffusion limiting film holding plate mounting member, (33) ... Through hole, (34) ... Diffusion limiting film holding plate accommodating groove, (44) ... Diffusion limiting film, (62) ...
Engaging shaft, (66) ... Groove, (66a) (66b) ... Upward recess,
(67) ... Rotating member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Yamazaki 2 at 1000 Otani Okamoto-cho, Kusatsu City, Shiga Prefecture Daikin Industries, Ltd. Shiga Works

Claims (6)

[Scope of utility model registration request] 1. A body fluid measuring electrode (3) provided at a predetermined position of a casing (1), a through hole (33) capable of accommodating the electrode (3), and a diffusion limiting film holding plate (4). A diffusion limiting film holding plate mounting member (32) having a movable groove (34) and reciprocatingly provided at a predetermined position of the casing so as to approach and separate from the electrode (3), and a diffusion limiting film holding member. A predetermined position of the casing (1) for positioning the plate mounting member (32) at a position moved a predetermined distance away from the electrode (3) or at a position moved a predetermined distance away from the electrode (3). A diffusion limiting film attachment mechanism in a biosensor, comprising: a positioning part (13) provided on the. 2. The diffusion limiting film in the biosensor according to claim 1, wherein the diffusion limiting film holding plate mounting member (32) is rotatably provided with one end as a fulcrum. Mounting mechanism. 3. A diffusion limiting film holding plate mounting member (32) stores the diffusion limiting film holding plate (4) in the groove (34) only by sliding the diffusion limiting film holding plate (4), or The diffusion limiting film mounting mechanism in the biosensor according to claim 1 or 2, which can be taken out from the groove (34). 4. A swing member (wherein the positioning portion (13) has a guide groove (66) for engaging with an engagement shaft (62) provided at a predetermined position of the diffusion limiting film holding plate mounting member (32). 67) and
Any one of claims 1 to 3 in which the guide groove (66) has a pair of engaging portions (66a) (66b) positioned on a straight line with a swing center. A diffusion limiting film attachment mechanism in the biosensor according to Crab. 5. Positioning is carried out by a positioning part (13),
The position moved by a predetermined distance in the direction approaching the electrode (3) is
The biosensor according to any one of claims 1 to 4, wherein the mounted diffusion limiting film holding plate (4) is set so as to be capable of being pressed against the surface of the electrode (3). Diffusion limiting membrane attachment mechanism in. 6. Positioning is performed by a positioning part (13),
The above utility model registration in which the position moved by a predetermined distance in the direction away from the electrode (3) is set so that the attached diffusion limiting film holding plate (4) is not in contact with the surface of the electrode (3). A diffusion limiting film attachment mechanism in the biosensor according to any one of claims 1 to 4.