CN102445471B - Electrochemical sensory test piece - Google Patents

Abstract

An electrochemical sensing test piece comprises a shell unit, electrode units respectively arranged in the shell unit, a reagent reaction layer and a filter element. The shell unit comprises an insulating substrate and a cover plate which are matched to define a containing space, an opening part and a guide channel. The insulating substrate is provided with an inner groove surface which is matched with the accommodating space to form the accommodating space, and a plurality of through holes which are formed on the inner groove surface, and the electrode units are respectively arranged in the through holes and are provided with at least one sunken top surface which is lower than the inner groove surface. The filter element extends from the opening part into the containing space through the guide channel and covers part of the reagent reaction layer and part of the electrode unit. Therefore, the liquid to be detected can be guided to the reagent reaction layer in an accelerated manner, the reaction time is shortened, and the sensing efficiency of the electrochemical sensing test piece can be improved.

Description

Electrochemical sensory test piece

technical field

The invention relates to a sensory test piece, in particular to a disposable electrochemical sensory test piece.

Background technique

The Electrochemical Sensor Strip has been widely used in the detection of various fluids. Its basic structure mainly includes a container with an opening for accommodating the fluid to be tested, and a layer fixed on the container. A chemical reagent (Reagent) layer that will electrochemically interact with a specific analyte of the fluid to be measured is contained in the container, and an electrode system is arranged in the container. Wherein, after the chemical reagent interacts with the analyte in the fluid to be tested, an output signal of an electrical parameter will be generated, and the concentration of the analyte in the fluid to be tested can be obtained through the output value of the electrical parameter, and the electrode system is It has a counter electrode (counter Electrode), a working electrode (Working Electrode), a reference electrode (Reference Electrode) and a detection electrode (Detecting Electrode). Among them, by changing the types of chemical reagents fixed in the container, electrochemical sensing test strips suitable for different test objects such as blood sugar, uric acid, cholesterol concentration, heavy metals, pesticides and toxic chemical components in sewage can be produced.

In order to obtain more accurate detection results, substances in the fluid to be tested that may interfere with the detection results are usually removed first. Taking whole blood as an example, since red blood cells will affect the sensing results, a filter membrane is usually set between the opening of the container and the chemical reagent layer to separate the plasma from the red blood cells in the whole blood and filter out the red blood cells, for example , U.S. Patent No. 5,139,685 discloses that the use of glass fiber filter membranes can separate blood cells from plasma without centrifugation, but when the amount of blood tested is small, it is easy to cause the filtered liquid due to the adsorption capacity of the filter membrane itself. If the amount is too small, the blood cells in the whole blood must be completely filtered out by applying more pressure, but under the action of pressure, it is easy to cause hemolysis and lead to inaccurate detection results. In addition, the adsorption force between the plasma and the filter membrane will also slow down the progress of the plasma, resulting in a longer time to obtain the response result.

Referring to Fig. 1, as disclosed in U.S. Patent No. 6,319,719, the electrochemical sensory test strip 1 is provided with a plurality of first barrier bumps 11 arranged at intervals and approximately in the shape of a half moon in the flow channel through which the fluid to be tested passes. Several second blocking projections 12 and several third blocking projections 13 are used as structures for blocking and removing red blood cells in whole blood, and mainly use three-dimensional structures to form obstacles for blocking red blood cells, and allow the plasma part to quickly pass through the The gaps between the blocking bumps 11 , 12 , 13 advance toward a reagent reaction layer 14 . But this kind of design requires a larger flow channel space to construct a sufficient number of first blocking projections 11, second blocking projections 12, and third blocking projections 13 to separate blood cells from plasma, and it is necessary to provide more The blood volume can successfully obtain the sensing results. In addition, the shapes and sizes of the first blocking bumps 11, the second blocking bumps 12, and the third blocking bumps 13, as well as the intervals between the blocking bumps 11, 12, and 13 are microscopic with certain specifications. Therefore, the structure of the first blocking bump 11, the second blocking bump 12, and the third blocking bump 13 needs to be produced by etching. In this way, not only the process time is prolonged, but the manufacturing cost is also greatly increased, resulting in The sensory test piece 1 has poor economic benefits in manufacturing and production, and its industrial applicability is relatively low.

In addition, as disclosed in U.S. Patent No. 6,966,977, the electrochemical sensing test piece mainly uses a filter to filter the fluid to be tested, and guides the blood plasma filtered out of blood cells into the test solution supply channel equipped with a reaction layer and an electrode system. Add the following restrictions: the cross-sectional area of the inlet side of the filter is larger than the cross-sectional area of the output side, and the cross-sectional area of the test solution supply channel and the opening adjacent to the filter are smaller than the cross-sectional area of the filter inlet side cross-sectional area. By reducing the cross-sectional area of the tip portion (output side) of the filter adjacent to the test solution supply channel, blood plasma can flow to the filter tip and enter the test solution supply channel more quickly. However, this type of electrochemical sensing test piece actually still has the following disadvantages:

1. When the filter, the test solution supply channel and the electrode system are arranged horizontally and laterally, the output side of the filter cannot extend through the opening of the test solution supply channel during installation, otherwise It will touch the electrode system and affect the detection results, and even if this configuration can make the plasma reach the front of the filter more quickly through the change of the cross-sectional area of the filter, it must accumulate enough to trigger an effective response. The measurement still takes a long time, so that the sensing test piece still needs a long time to obtain the detection result.

2. Since the test solution supply channel of the sensing test piece is designed to match the reaction layer and the electrode system to a predetermined space size, and its size is not easy to change, in order to comply with the cross-sectional area of the inlet side of the filter is larger than the test solution supply The design requirements of the channel will inevitably widen or thicken the size of the filter, which may cause the overall volume of the filter to increase. On the contrary, it is necessary to increase the amount of fluid to be tested to obtain the detection result smoothly, and it will also prolong the time. detection time.

Another example is the electrochemical sensing test piece disclosed in U.S. Patent No. 5,628,890, which is used for the opening, the filter layer and the electrode unit to be dripped into the fluid to be tested in a vertical configuration pattern. Due to this vertical configuration structure, the filter layer It will cover all the electrodes (three electrodes in its embodiment), although this kind of structural arrangement seems to shorten the distance between the place where the blood to be tested is dropped and the electrode unit, and it is possible to obtain the measurement results more quickly, but in order to To really filter red blood cells in the blood, it is still necessary to increase the number of filter layers and combine several layers of electrical insulation layers of hydrophobic materials to form a multi-layer structure, and this multi-layer structure requires a large amount of blood to successfully obtain measurement results , and usually need to be equipped with a micro-pump or apply pressure, otherwise the detection result will be inaccurate, because the electrochemical sensor test piece with this structure requires a large number of components, must be equipped with a pressure device, and needs to provide a relatively large number of components. There is a lot of test blood, but there is still room for improvement.

The above description shows that there are different types of sensory test pieces to improve detection accuracy and detection speed, but in order to provide products with better usability, there is still a demand for continuous development of different design types of sensory test pieces.

Contents of the invention

The object of the present invention is to provide an electrochemical sensing test piece which is relatively easy to manufacture, helps to obtain accurate sensing results quickly, and has better quantitative detection performance.

The electrochemical sensing test piece of the present invention is suitable for detecting a target analyte in a fluid to be measured, and the sensing test piece comprises a casing unit, an electrode unit respectively arranged in the casing unit, and an electrode unit connected to the casing unit. The reagent reaction layer in contact with the electrode unit, and a filter element covering part of the reagent reaction layer and part of the electrode unit.

The housing unit includes an insulating base plate and a cover plate that are connected correspondingly, and the insulating base plate and the cover plate cooperate to define an accommodating space, an opening, and a The insulating substrate has an extended groove surface that cooperates to form the guide channel, an inner groove surface that is adjacent to the extended groove surface and cooperates to form the accommodation space, and several spaced apart ones facing the cover plate. The through hole formed on the surface of the inner groove.

The electrode units are respectively arranged in the through holes of the insulating substrate of the housing unit, and have at least one sunken top surface lower than the surface of the inner groove.

The reagent reaction layer is arranged in the containing space of the shell unit and contacts with the electrode unit, and includes a sensing reagent capable of reacting with target analytes.

The filter element is made of a material with a pore structure, and extends laterally from the opening of the housing unit through the guide channel into the containing space, and covers part of the reagent reaction layer and part of the depression of the electrode unit On the top surface, the filter element has a wide diameter section located at the opening of the housing unit, a narrow diameter section located in the containing space, and a connection between the wide diameter section and the narrow diameter section and from the The wide-diameter section to the narrow-diameter section is a connecting section whose width tapers.

Preferably, the insulating substrate of the housing unit has two spaced through holes, and the electrode unit includes a first electrode and a working electrode respectively inserted in the through holes, and the sunken top of the electrode unit The surface is formed on at least one of the first electrode and the working electrode, and the first electrode is selected from a counter electrode, a reference electrode, and a combination of the counter electrode and the reference electrode.

Preferably, the sunken top surface of the electrode unit is formed on the first electrode, and the filter element covers part of the reagent reaction layer and the sunken top surface of the first electrode.

Preferably, the sunken top surface of the electrode unit can also be formed on the working electrode, and the filter element covers part of the reagent reaction layer and the sunken top surface of the working electrode.

Preferably, the electrode unit can also have two sunken top surfaces, which are respectively formed on the first electrode and the working electrode, and the filter element covers part of the reagent reaction layer, and covers the first electrode and the working electrode. The sunken top surface of one of the electrodes.

Preferably, the filter element is in the form of an inverted triangle, and the narrow diameter section terminates at a terminal edge.

Preferably, the end edge of the narrow-diameter section of the filter element is rounded to form an arc profile.

Preferably, the extended groove surface of the insulating substrate is designed to be narrower from the opening to the inner groove surface corresponding to the shape of the filter element, and can be accommodated by the filter element.

Preferably, the extension groove surface of the insulating substrate of the housing unit has a stepped structure that gradually climbs upward from the opening to the inner groove surface, and the filter element is arranged along the extension groove surface and sandwiched on the insulating surface. between the substrate and the cover.

Preferably, the housing unit also includes a suction port communicating with the containing space, and the sensing test piece also includes a corresponding suction port installed on the housing unit for attracting the to-be-treated filter element on the filter element A suction device that measures fluid progressing toward the containment space.

Preferably, the cover plate of the housing unit also has an air hole corresponding to the accommodating space.

Preferably, the pore size of the pore structure of the filter element is 0.8 μm-8 μm.

Preferably, the cover plate of the housing unit has an arc-shaped notch corresponding to the opening and recessed toward the accommodating space, and the wide-diameter section of the filter element has an arc-shaped notch corresponding to the arc-shaped notch. Bare samples enter the area.

Preferably, the longitudinal gap between the extending groove surface of the insulating substrate and the cover plate gradually decreases from the opening to the containing space, so that the closer the filter element is to the containing space, the greater the extrusion force is.

Preferably, the density of the filter element gradually increases from the opening of the housing unit to the containing space, and the average pore size of the pore structure decreases gradually.

Preferably, the electrochemical sensing test strip can be applied to a product selected from the following group: household medical detectors, biosensors and sensors for detecting specific biochemical components in fluids.

The beneficial effects of the present invention are: by making the filter element extend into the accommodation space of the housing unit, it is possible to accelerate and guide the target analyte in the fluid to be measured to reach the reagent reaction layer and has been combined with the electrode unit. It is relatively close, so that the required response time can be shortened, and the detection result can be obtained more quickly, so that the present invention can provide better sensing efficiency.

Description of drawings

Fig. 1 is a schematic top view illustrating the situation in which several half-moon-shaped blocking bumps are formed in a sensing test piece in US Patent No. 6,319,719;

Fig. 2 is a three-dimensional exploded schematic view that does not contain a reagent reaction layer, illustrating the configuration of a housing unit, an electrode unit and a filter element of the first preferred embodiment of the electrochemical sensor test piece of the present invention;

Fig. 3 is a schematic top view illustrating the situation in which the first preferred embodiment is assembled;

Fig. 4 is a schematic cross-sectional view taken along the line IV-IV in Fig. 3, illustrating the arrangement of the filter element, electrode unit and one layer of reagent reaction layer in the housing unit of the first preferred embodiment;

Fig. 5 is a schematic sectional view illustrating the situation that the second preferred embodiment of the electrochemical type sensing test piece of the present invention is provided with a suction device;

Figure 6 is a schematic top view illustrating different designs of an insulating substrate of the housing unit;

Fig. 7 is a sectional view taken along line VII-VII in Fig. 6;

Figure 8 is a schematic top view illustrating another design of the insulating substrate of the housing unit;

Fig. 9 is a sectional view taken along line IX-IX of Fig. 8 .

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numerals.

Referring to FIG. 2, FIG. 3 and FIG. 4, a first preferred embodiment of the electrochemical sensing test strip 2 of the present invention is suitable for detecting a target analyte 101 in the fluid 10 to be tested, and the sensing test strip 2 includes a shell Body unit 3, an electrode unit 4 arranged in the housing unit 3, a reagent reaction layer 5 in contact with the electrode unit 4, and a filter covering part of the reagent reaction layer 5 and part of the electrode unit 4 Element 6. In this embodiment, a blood glucose meter is used as an example to illustrate the sensing test strip 2, that is to say, the fluid 10 to be tested is whole blood, the target analyte 101 is blood sugar, and blood cells in the whole blood are interfering substances 102. However, the type of the sensing test strip 2 should not be limited in this way. By changing the composition of the reagent reaction layer 5, the sensing test strip 2 can also be used to detect uric acid and cholesterol in addition to detecting blood sugar in the blood. concentration and the concentration of heavy metals, pesticides and toxic chemical components in sewage, thereby enabling the sensory test piece 2 to be further made into biosensors, sensors for detecting specific biochemical components in fluids, and household medical detection Devices and other electrochemical sensor products.

The housing unit 3 includes an insulating base plate 31 and a cover plate 32 that are joined together correspondingly. The insulating base plate 31 cooperates with the cover plate 32 to define a housing space 301, an opening 302, and a The guiding passage 303 between the space 301 and the opening 302 .

The insulating substrate 31 has an extending groove surface 311 facing the cover plate 32 to form the guide channel 303 , an inner groove surface 312 adjacent to the extending groove surface 311 and forming the receiving space 301 , and several Through holes 315 are formed on the inner groove surface 312 at intervals. Wherein, the extending groove surface 311 has a stepped structure gradually climbing up from the opening 302 to the inner groove surface 312. In this embodiment, the extending groove surface 311 has a first step adjacent to the opening 302. 313 , and a second step portion 314 adjacent to the inner groove surface 312 , and the height of the second step portion 314 is higher than the height of the first step portion 313 . Wherein, the first step portion 313 and the second step portion 314 are obtuse angle structures with an angle greater than 90°. In addition, the number of steps can be increased or decreased according to actual needs.

The cover plate 32 has an arc-shaped notch 321 corresponding to the opening 302 and recessed toward the accommodating space 301 so that part of the filter element 6 is exposed; The viewing channel 322 of the accommodation space 301 and an air hole 323 corresponding to the accommodation space 301 pass through. The pores 323 are mainly used to induce capillary action, so that the fluid 10 to be tested can smoothly advance to the containing space 301 along the guide channel 303 in the filter element 6 .

Preferably, the housing unit 3 further includes an observation window plate 33 that covers the viewing channel 322, and the user can view the filter element 6 arranged along the guide channel 303 through the observation window plate 33, and then The movement of the fluid to be tested 10 on the filter element 6 can be observed during detection.

The electrodes of the electrode unit 4 are respectively disposed in the through holes 315 of the insulating substrate 31 of the housing unit 3 , and have at least one sunken top surface 401 lower than the inner groove surface 312 .

In this embodiment, the insulating substrate 31 has two spaced through holes 315, and the electrode unit 4 includes a first electrode 41 which is not falling off and is respectively plugged in the through holes 315, and a A working electrode (wording electrode) 42, the electrode unit 4 has two sunken top surfaces 401 respectively formed on the first electrode 41 and the working electrode 42, the first electrode 41 is selected from the counter electrode (counter electrode) , a reference electrode (reference electrode), and combinations of said electrodes. The first electrode 41 used in this embodiment is formed by combining the counter electrode and the reference electrode and has a double-electrode function, and the first electrode 41 is adjacent to the extension groove surface 311, while the working electrode 42 is far away from the extension groove surface 311, but the first electrode 41 and the working electrode 42 can still achieve the same function by exchanging positions. After the setting is completed, the sunken top surfaces 401 of the first electrode 41 and the working electrode 42 are all lower than the inner groove surface 312, whereby the sunken top surfaces 401 of the first electrode 41 and the working electrode 42 are respectively Cooperating with the through holes 315 , two recessed spaces 316 are formed. Wherein, the number of electrodes of the electrode unit 4 is not limited, and different numbers of electrodes can be matched due to different requirements of electrochemical action in practical applications. Therefore, the electrode unit 4 can also be formed by including a working electrode, a counter electrode and a reference electrode. A three-electrode system, or a multi-electrode system including a working electrode, a counter electrode, a reference electrode and at least one detecting electrode. In addition, it is also possible to form the sunken top surface 401 only on the first electrode 41, or only on the working electrode 42, and make the electrode formed with the sunken top surface 401 adjacent to the extension groove surface 311 during the arrangement, and still achieve the predetermined Effect.

The reagent reaction layer 5 is disposed in the containing space 301 of the shell unit 3 and contacts the electrode unit 4 , and includes a sensing reagent 51 capable of reacting with the target analyte 101 . Wherein, the reagent reaction layer 5 is not only coated along the inner groove surface 312 , but also fills the recessed space 316 on the top surfaces of the first electrode 41 and the working electrode 42 .

The filter element 6 is made of a material with a pore structure, and the pore diameter of the pores in the pore structure is 0.8 μm˜8 μm. In addition, the filter element 6 extends laterally from the opening 302 of the housing unit 3 through the guide channel 303 into the accommodation space 301, and covers part of the reagent reaction layer 5 and part of the sunken roof of the electrode unit 4. Face 401. Since the electrode unit 4 of this embodiment has a sunken top surface 401 formed on the first electrode 41 and the working electrode 42, the filter element 6 can only cover the Covering the sunken top surface 401 of one of the electrodes usually covers the sunken top surface 401 of the electrode that is closer to the guiding channel 303 . In addition, if only one of the electrodes 41 , 42 is formed with the sunken top surface 401 , the filter element 6 is made to cover the one electrode 41 , 42 formed with the sunken top surface 401 . In this embodiment, the filter element 6 is covered on the first electrode 41 . In addition, if the electrode unit 4 is a three-electrode system, the filter element 6 can only cover one of the electrodes, or two of the electrodes. It is a principle that the filter element 6 completely covers all electrodes.

Preferably, the filter element 6 has a wide-diameter section 61 that can be placed in the opening 302, a narrow-diameter section 62 that can be placed in the containing space 301, and a Between the diameter sections 62 and from the wide diameter section 61 to the narrow diameter section 62 is a connecting section 63 whose width tapers. The wide diameter section 61 has a circular arc-shaped gap 321 corresponding to the cover plate 32 and is an exposed sample entry area. 611. In this embodiment, the filter element 6 has an inverted triangular membrane structure whose width gradually decreases from large to large, and the narrow-diameter section 62 terminates at an end edge 621 . Wherein, in order to cause the filtrate containing the target analyte 101 to trigger the electrochemical reaction faster to obtain the sensing result quickly, the filter element 6 is extended into the containing space 301, therefore, the end edge 621 is located at the reagent above the reaction layer 5 and the electrode unit 4 (see FIG. 4 ), whereby the filtrate containing the target analyte 101 enters the reagent reaction layer 5 and is quite close to the electrode unit 4, so the electrode unit 4 can be triggered more quickly. Unit 4 generates a response.

It is worth noting that although the filter element 6 is configured to cover the first electrode 41, the design of the end edge 621 with a pointed structure can still allow the filtrate containing the target analyte 101 to be filtered. Concentrated collection and fast flow out, so that the sensing results can be obtained quickly. In addition, by forming the sunken top surface 401 on the first electrode 41 to define the recessed space 316, the filter element 6 and the first electrode 41 have a larger separation distance, so even if the filter element 6 extends to Covering the position above the first electrode 41 does not prevent the filter element 6 from touching the first electrode 41 and interfering with the detection result, so accurate sensing results can be obtained smoothly.

Preferably, due to the shape of the filter element 6, there will be a gap between the flow velocity of the fluid to be tested 10 at the tip of the filter element 6 and the two side wings, because the flow velocity difference at different positions is too large to easily generate air bubbles to wrap it, for To avoid this bad situation, the end edge 621 is rounded to form a circular arc profile, which can reduce the generation of air bubbles and prevent the detection accuracy from being affected. Moreover, this structural design does not affect the effect that the filtrate containing the target analyte 101 is collected through the filter element 6 and flows out quickly, and makes it easier for the reagent reaction layer 5 to detect the target analyte 101, and can Quickly provide more accurate answer results.

In addition, the filter element 6 is arranged along the extending groove surface 311 of the insulating substrate 31 of the housing unit 3, and is sandwiched between the insulating substrate 31 and the cover plate 32. In this embodiment, the extending groove The longitudinal gap between the surface 311 and the cover plate 32 gradually narrows from the opening 302 to the accommodation space 301, so that the closer the filter element 6 is to the accommodation space 301, the greater the extrusion force, in addition to making the filter The cross-sectional area of the element 6 from the opening 302 to the accommodation space 301 is gradually reduced due to being squeezed, the density of the filter element 6 will gradually increase, and the average pore size of the pore structure will also increase. From the wide-diameter section 61 to the terminal edge 621 , the blocking effect on the interfering substance 102 is greater as it gets closer to the terminal edge 621 , which facilitates the rapid separation of the interfering substance 102 and the target analyte 101 . In addition, the extended groove surface 311 is designed to be narrower from the opening 302 to the inner groove surface 312 corresponding to the shape of the filter element 6, and can be accommodated by the filter element 6, thereby The structural design of the engagement of the extending groove surface 311 with the filter element 6 can limit the displacement of the filter element 6 and provide an auxiliary positioning effect.

It should be added that, in this embodiment, the filter element 6 is made of glass fiber material, but the material of the filter element 6 should not be limited in this way, and the filter element 6 can also be made of a blended fiber material, and In this embodiment, in order to achieve the effect of filtering out the interfering substances (red blood cells) 102 and allowing the target analyte 101 to pass through smoothly, the pores of the filter element 6 are matched with the particle size difference between the interfering substance 102 and the target analyte 101 The average pore size of the structure is designed to be 0.8 μm to 8 μm.

When in use, a predetermined amount of the fluid 10 to be tested is dropped from top to bottom on the sample entry area 611 of the filter element 6 exposed from the arc-shaped notch 321 of the cover plate 32, so that the fluid 10 to be tested is adsorbed to the filter element 6. In the filter element 6, then, move along the filter element 6 through the guide channel 303 to the containing space 301 by capillary action, because the target analyte 101 and the interfering substance 102 in the fluid 10 to be measured are in the filter element 6 The adsorption force and capillary force in the medium are different, so that the two achieve the purpose of phase separation due to the difference in moving speed, so that the target analyte 101 with a faster moving speed reaches the reagent reaction layer 5 first, and can A biochemical reaction occurs with the sensing reagent 51 without interference, and then a signal is triggered through the electrode unit 4, so that more accurate detection results can be obtained.

In addition, by using the extension groove surface 311 and the inner groove surface 312 of the insulating substrate 31 to cooperate with the cover plate 32, the opening area of the opening 302 in the advancing direction of the fluid to be measured 10 is larger than that of the guiding channel 303. Opening area, and the opening area of the guide channel 303 is larger than the opening area of the accommodating space 301, which also makes the filter element 6 flow from the opening 302 to the accommodating space due to different degrees of extrusion force. The space 301 shows a more significant change in the gradually shrinking cross-sectional area, which helps to quickly separate the interfering substance 102 and the target analyte 101 in the fluid to be measured 10 .

As shown in Figure 6, it can be seen from the top view that the extended groove surface 311 of the insulating substrate 31 and the outer surface portion corresponding to the opening 302 are trapezoidal in width from outside to inside, while the inner groove surface 312 is in the shape of a trapezoid. A long finger shape with a fixed width. Preferably, the insulating substrate 31 also has a laterally protruding stop bar 317 blocked between the inner groove surface 312 and the extension groove surface 311, as shown in FIG. 7 , is The cross-sectional view taken from the line VII-VII of FIG. 6 shows that the extension groove surface 311 is in the form of a gradually rising slope from the opening 302 to the retaining bar 317, thereby, when matched with the cover plate 32 (see FIG. 2 ) , it will show the state that the area of the opening formed by the inner groove surface 312 is gradually reduced, and then the filter element 6 clamped between the cover plate 32 (see FIG. 2 ) and the insulating substrate 31 (see FIG. 2 ) 2) Produce different degrees of extrusion effects. In addition, when the reaction reagent is coated on the inner groove surface 312 to form the reagent reaction layer 5 (see FIG. 4 ), the bar 317 can be used to prevent the reaction reagent from leaking from the inner groove surface 312 and flowing into the opening 302 , to successfully complete the coating of the reaction reagent.

As shown in FIG. 8, it is another design type of the insulating substrate 31. It can be seen from the top view that the extension groove surface 311 and the outer surface portion corresponding to the opening 302 are designed as closed circular grooves. The inner groove surface 312 is also in the shape of a long finger with a fixed width. A transversely protruding retaining strip 317, as shown in Figure 9, is a cross-sectional view taken from line IX-IX in Figure 8, showing that a groove space is defined and formed on the extended groove surface 311, and has a groove bottom 318 and its own The groove side 319 extending upwards from the bottom of the groove 318, and the part of the side of the groove 319 adjacent to the bar 317 is in the form of a slope that gradually rises from the bottom of the groove 318 to the bar 317, whereby when When matched with the cover plate 32 (see FIG. 2 ), this type of insulating substrate 31 also presents a state that the area of the opening formed gradually decreases as it gets closer to the inner groove surface 312 . In addition, the bar 317 can also prevent the coated reaction reagent from leaking from the inner groove surface 312 , so that the coating of the reaction reagent can be successfully completed.

Referring to Fig. 5, it is a second preferred embodiment of the electrochemical sensing test strip of the present invention, the main difference between the second preferred embodiment and the first preferred embodiment is that the sensing test strip 2 also includes a corresponding The suction device 7 provided by the filter element 6, and in order to avoid the weakening of the suction effect of the suction device 7, the cover plate 32 is not provided with the air hole 323 (see Figure 4), and the rest is the same as the first preferred embodiment, No longer.

Cooperate with the installation of the suction device 7, the housing unit 3 also includes a suction port 304 communicating with the accommodating space 301, and the suction device 7 is installed on the housing unit 3 corresponding to the suction port 304 for suction The fluid to be tested 10 on the filter element 6 advances toward the containing space 301 to accelerate the moving speed of the fluid to be tested 10 , thereby assisting in improving the filtering efficiency. In this embodiment, the suction port 304 is formed on the insulating substrate 31, and the suction device 7 forms a suction force in the containing space 301 through the suction port 304, so as to attract the fluid 10 to be measured to move toward the containing space 301. . Wherein, the suction device 7 is a micropump.

To sum up the above, the electrochemical type sensing test piece 2 of the present invention can obtain the following effects and advantages, so the object of the present invention can be achieved:

1. The electrochemical sensing test piece 2 of the present invention belongs to a lateral arrangement structure, that is, the sample entry area 611 for receiving the fluid 10 to be tested on the filter element 6 and the electrode unit 4 are staggered along a horizontal direction The type of configuration, whereby the effect of separating the target analyte 101 and the interfering substance 102 can be achieved only through the capillary action of the filter element 6, without the need to set multiple covering layers as in US Patent No. 5,628,890 and provide relatively A large amount of fluid 10 to be tested can successfully filter out interfering substances 102 and obtain test results. The present invention can further accelerate the process by making the filter element 6 extend laterally into the accommodation space 301 of the housing unit 3. When the filtrate containing the target analyte 101 in the fluid to be tested 10 is guided to reach and enter the reagent reaction layer 5, it is already quite close to the electrode unit 4, thereby shortening the required reaction time and obtaining more quickly detection results.

2. Through the structural characteristics of the inverted triangular membrane of the filter element 6, the total adsorption area and volume of the filter element 6 can be reduced by about half compared with the existing rectangular filter membrane, and the required waiting time can be effectively reduced. Measure the amount of fluid 10, and even if the amount is reduced, the filter element 6 is designed to gradually narrow in width in the forward direction of the fluid 10 to be measured, which can promote the target analyte 101 to gradually gather at the end edge 621 and enter the reagent reaction. The layer 5 interacts with the sensing reagent 51 to trigger relevant biochemical reactions and responses, thereby enabling the present invention to reduce the amount of the fluid to be tested 10 and still obtain accurate detection results.

3. By extending the filter element 6 to cover part of the reagent reaction layer 5 and part of the electrode unit 4, there is a larger overlapping area between the filter element 6 and the reagent reaction layer 5, and through the extension The target analyte 101 in the second step portion 314 of the groove surface 311 can enter the reagent reaction layer 5 in a large amount in a relatively short period of time, and the interfering substance 102 in the fluid to be tested 10 will also be affected by the dual action of gravity and adsorption force. It is more difficult to reach the second stage portion 314 without interfering with the detection results, thereby enabling the target analyte 101 to simultaneously undergo a biochemical reaction with the sensing reagent 51 in the reagent reaction layer 5 and produce a response in a short time , which can also improve the sensing efficiency.

4. The opening area of the housing unit 3 from the opening 302 to the accommodation space 301 through the guide channel 303 is gradually reduced, the density and the average pore size of the filter element 6 can be changed, and the fluid to be measured 10 The faster separation of the target analyte 101 from the interfering substance 102 also contributes to improved sensing efficiency.

5. Using the filter element 6 with the suction device 7 can further accelerate the moving speed of the target analyte 101, so that the present invention can quickly obtain detection results and have better sensing efficiency, thus meeting the practical requirements of fast and accurate.

6. By designing the extended groove surface 311 of the insulating substrate 31 into a stepped structure surface type that gradually climbs upwards, the filter element 6 follows the surface structure of the extended groove surface 311 in the guide channel 303 along with the fluid to be measured. The forward direction of 10 forms a state extending upward from the downward slope, whereby the moving speed difference between the target analyte 101 and the interfering substance 102 can be further enlarged so that it can be separated quickly, and the interfering substance with relatively large weight and volume 102 is less likely to enter the reagent reaction layer 5, which makes the present invention less susceptible to interference during detection and helps to obtain more accurate detection results.

Claims (17)

1. An electrochemical type sensing test piece is suitable for detecting the concentration of a target analyte in a fluid to be measured, and the sensing test piece comprises a housing unit, an electrode unit respectively arranged in the housing unit, A reagent reaction layer and a filter element, characterized in that: The housing unit includes an insulating base plate and a cover plate that are connected correspondingly, and the insulating base plate and the cover plate cooperate to define an accommodating space, an opening, and a The insulating substrate has an extended groove surface that cooperates to form the guide channel, an inner groove surface that is adjacent to the extended groove surface and cooperates to form the accommodation space, and several spaced apart ones facing the cover plate. A through hole formed on the inner groove surface; The electrode units are respectively arranged in the through holes of the insulating substrate of the housing unit, and have at least one sunken top surface lower than the inner groove surface; The reagent reaction layer is arranged in the accommodation space of the housing unit and is in contact with the electrode unit, including a sensing reagent that reacts with the target analyte; The filter element is made of a material with a pore structure, and extends laterally from the opening of the housing unit through the guide channel into the containing space, and covers part of the reagent reaction layer and part of the depression of the electrode unit On the top surface, the filter element has a wide diameter section located at the opening of the housing unit, a narrow diameter section located in the containing space, and a connection between the wide diameter section and the narrow diameter section and from the A connecting section whose width tapers from the wide diameter section to the narrow diameter section. 2. The electrochemical sensor test strip according to claim 1, characterized in that: the insulating substrate of the housing unit has two through holes spaced apart, and the electrode unit includes a plugged in the through holes respectively. A first electrode, and a working electrode, the sunken top surface of the electrode unit is formed on at least one of the first electrode and the working electrode, and the first electrode is selected from a counter electrode, a reference electrode, and the above-mentioned combination of the counter electrode and the reference electrode. 3. The electrochemical sensing test strip according to claim 2, characterized in that: the sunken top surface of the electrode unit is formed on the first electrode, and the filter element covers part of the reagent reaction layer and the sunk of the first electrode top surface. 4. The electrochemical sensing test strip according to claim 2, characterized in that: the sunken top surface of the electrode unit is formed on the working electrode, and the filter element covers part of the reagent reaction layer and the sunken top surface of the working electrode . 5. The electrochemical sensing test strip according to claim 2, characterized in that: the electrode unit has two sunken top surfaces, which are respectively formed on the first electrode and the working electrode, and the filter element covers part of the reagent The reaction layer covers the sunken top surface of one of the first electrode and the working electrode. 6 . The electrochemical sensing test strip according to claim 1 , wherein the filter element is in the shape of an inverted triangle, and the narrow-diameter section terminates at an end edge. 7 . 7 . The electrochemical sensor test strip according to claim 6 , wherein the end edge of the narrow-diameter section of the filter element is rounded to form an arc profile. 8 . 8. The electrochemical sensor test piece according to claim 1, characterized in that: the extended groove surface of the insulating substrate is a design pattern in which the groove gradually narrows from the opening to the inner groove surface corresponding to the shape of the filter element, And it can be accommodated by the filter element. 9. The electrochemical sensor test piece according to claim 1, characterized in that: the extended groove surface of the insulating substrate of the housing unit is in a stepped structure that gradually climbs upward from the opening to the inner groove surface, and the The filter element is arranged along the surface of the extending groove and sandwiched between the insulating substrate and the cover plate. 10. The electrochemical sensing test piece according to claim 1, characterized in that: the housing unit also includes a suction port communicated with the containing space, and the sensing test piece also includes a corresponding suction port installed In the housing unit, a suction device for attracting the fluid to be measured on the filter element to advance toward the containing space. 11 . The electrochemical sensor test strip according to claim 1 , wherein the cover plate of the housing unit also has an air hole corresponding to the containing space. 12 . 12. The electrochemical sensor test piece according to claim 1, characterized in that: the pore size of the pore structure of the filter element is 0.8 μm-8 μm. 13. The electrochemical sensor test piece according to claim 1, characterized in that: the cover plate of the housing unit has an arc-shaped notch corresponding to the opening and recessed toward the containing space, the filter element Then there is an exposed sample entry area corresponding to the arc-shaped notch. 14. The electrochemical sensor test piece according to claim 1, characterized in that: the longitudinal gap between the extension groove surface of the insulating substrate and the cover plate gradually narrows from the opening to the containing space, so that the filter element The closer it is to the accommodation space, the greater the extrusion force it bears. 15. The electrochemical sensor test strip according to claim 14, characterized in that: the density of the filter element from the opening of the housing unit to the containing space increases gradually, and the average pore size of its pore structure decreases gradually . 16. The electrochemical sensor test piece according to claim 1, characterized in that: the density of the filter element gradually increases from the opening of the housing unit to the containing space, and the average pore size of its pore structure gradually decreases . 17. The electrochemical sensing test strip according to claim 1, characterized in that: the electrochemical sensing test strip is applied to a product selected from the following group: household medical detectors, biosensors and detection fluids Sensors for specific biochemical components.

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