JP2013130563A - Sensing sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensing sensor which is small-sized, allows a supply liquid to be easily distributed, and enables measurement with high reliability.SOLUTION: A sample liquid is supplied, by capillarity, to a flow passage which a piezoelectric vibrator 3 included in a sensing sensor 20 faces. Therefore, a pump for distributing the sample liquid is unnecessary while the sensing sensor is a flow cell type. A supply flow passage 10 is configured so as to have a lateral dimension (width) gradually increased from an inlet in a downstream direction, so that bubbles are hardly generated in the supply flow passage 10 because a flow rate in the supply flow passage 10 is not suddenly changed. Thus, the sensing sensor 20 which enables measurement with high reliability while being small-sized can be provided.

Description

  The present invention relates to a sensing sensor for sensing a sensing object using a piezoelectric vibrator that changes its natural frequency by adsorbing to the adsorption layer provided on the surface of the sensing object.

  As a method for detecting a detection object in a sample fluid, for example, a trace amount of protein in blood or serum, a detection sensor using QCM (Quartz Crystal Microbalance) as shown in Patent Document 1, for example, is shown. QCM uses a quartz oscillator with an adsorption film that adsorbs the sensing object on the surface of the excitation electrode by antigen-antibody reaction. The mass load due to the adsorption of the sensing object in the sample liquid is changed by changing the frequency of the quartz oscillator. This is to quantify the sensing object. Specifically, the frequency when the reference liquid that does not include the sensing object is supplied and the frequency when the sample liquid with the unknown presence or concentration of the sensing object is supplied are detected, and these frequencies are detected. The detection of the sensing object and the measurement of the concentration are performed assuming that the difference in frequency corresponds to the mass of the sensing object adsorbed on the adsorption film.

  When such a sensor is used, for example, in the clinical field or food inspection field, it is often performed using a simple device, and a small, simple device that accurately detects the device is required. ing. On the other hand, as a configuration of the QCM, there are known a flow-through cell type in which a sample liquid is continuously flowed to the surface of a crystal resonator and the sample liquid is discharged from the surface, and a static type in which the sample liquid is stored in the cell. The flow-through cell type normally prevents the sample liquid from being diluted with the reference liquid, and can prevent the mass of the sample liquid from affecting the frequency of the crystal unit in addition to the mass of the sensing object. Although excellent, there is a problem that the apparatus becomes large because a pump is required. Further, when the size of the sensing sensor is reduced, the supply flow path for supplying the supply liquid to the surface of the crystal unit becomes thin, and the area for installing the excitation electrode in the supply flow path becomes narrow. If the excitation electrode is reduced in size, the CI value of the crystal resonator increases, making it difficult to perform stable oscillation, and in the case of a highly viscous sample solution, there is a problem that measurement itself cannot be performed, and detection accuracy is increased. There was a problem of deterioration.

JP 2009-206792 A

  The present invention has been made under such circumstances, and an object of the present invention is to provide a small-sized and easy-to-use sensing sensor that can circulate a supply liquid and that can perform highly reliable measurement. There is to do.

The sensing sensor of the present invention comprises a wiring board having a connection terminal portion connected to a measuring instrument for measuring an oscillation frequency and having a recess formed on one surface side,
Excitation electrodes are respectively formed on a common piezoelectric piece fixed to the wiring board so as to close the recess, and each excitation electrode is electrically connected to the connection terminal portion. A piezoelectric vibrator;
In order to form a flow path between the first piezoelectric vibrator and the area on the one surface side of the wiring board including the second piezoelectric vibrator, a sample is provided in the flow path so as to cover the area. A flow path forming member in which an injection port for injecting a liquid and a waste liquid port for discharging the injected sample liquid are formed in front and back;
An adsorption layer provided on the excitation electrode on the flow path forming member side in the first piezoelectric vibrator and adsorbing a sensing object in the sample liquid,
The first excitation electrode and the second excitation electrode are arranged side by side in the flow path,
The flow path forming member circulates the sample liquid from the injection port to the waste liquid port via the one surface of both piezoelectric vibrators by capillary action, and the width of the flow channel increases in the downstream direction from the injection port. It is characterized by being configured.

In the sensor according to the present invention, the flow path forming member may be configured such that the width of the flow path narrows further toward the waste liquid port after the width of the flow path is widened.
Furthermore, in the detection sensor of the present invention, the flow path forming member may be characterized in that an opening angle of the flow path from the inlet to the downstream direction is 50 degrees to 65 degrees.

  According to the sensing sensor of the present invention, the sample liquid is supplied to the flow path facing the piezoelectric vibrator by capillary action. Therefore, although it is a flow-through cell type detection sensor, a pump for circulating the sample liquid is not necessary. In addition, since the left and right dimensions (width) gradually increase from the inlet toward the downstream from the inlet, the flow velocity in the supply channel does not change abruptly, so that bubbles are generated in the supply channel. Hard to occur. Therefore, it is possible to provide a detection sensor that can perform highly reliable measurement while being a small detection sensor.

1 is a perspective view of a sensing device according to the present invention. It is a perspective view of the sensing sensor which comprises the said sensing device. (A) A vertical side view of the sensing sensor and (b) a vertical side view in which a crystal resonator and a supply channel are enlarged. It is the disassembled perspective view which showed the lower surface side of each part of a detection sensor. It is the disassembled perspective view which showed the upper surface side of each part of a detection sensor. It is a top view which shows (a) upper surface side and (b) lower surface side of the crystal oscillator which comprises the said sensor. It is a top view which shows the state which installed the said crystal oscillator in the supply flow path. It is a schematic block diagram of the said sensing apparatus. It is process drawing which shows the mode of the measurement by the said sensing apparatus. It is process drawing which shows the mode of the measurement by the said sensing apparatus. It is process drawing which shows the mode of the measurement by the said sensing apparatus. It is (a) top view and (b) vertical side view of the supply flow path of the sensor which concerns on other embodiment.

  Hereinafter, a sensing device using the sensing sensor 20 according to the embodiment of the present invention will be described. This sensing device is configured to detect the presence or absence of human influenza virus infection by detecting the presence or absence of an antigen such as influenza virus in a sample liquid obtained from, for example, a human nasal wipe. Yes. As shown in the external perspective view of FIG. 1, the sensing device includes a measuring device 11 including an oscillation circuit unit 12 and a main body 13, and a detection sensor 20 that is detachably connected to the oscillation circuit unit 12 of the measuring device 11. And. The oscillation circuit unit 12 is connected to the main body 13 via, for example, a coaxial cable 14. The display unit 16 provided on the front surface of the housing 15 of the main body unit 13 serves to display, for example, measurement results such as frequency or a change in frequency, presence / absence of detection of viruses, and the like, and is configured by a liquid crystal display screen, for example. ing.

  FIG. 2 is a perspective view of the sensing sensor 20, and the wirings and electrodes in the subsequent drawings are hatched to distinguish them from the substrate or the like. FIG. 3 is a longitudinal side view of the sensing sensor 20. The dimensions in the height direction of the members in FIG. 3 are shown different from the actual dimensions for convenience of explanation. The sensing sensor 20 includes a wiring board 2, a crystal resonator 3, which is one of piezoelectric resonators, a flow path forming member 4, and an upper lid case 5, which are stacked from the bottom and have a length of about 2.0 cm. , Having a width of about 1.2 cm. 4 is an exploded perspective view showing the lower surface side of each part of the sensing sensor 20, and FIG. 5 is an exploded perspective view showing the upper surface side of each part of the sensing sensor 20. As shown in FIG. The sensing sensor 20 will be described with reference to FIGS.

  The wiring board 2 has a connection terminal portion 22 inserted into the oscillation circuit unit 12 on the rear side in the length direction. A square-shaped recess 23 is formed in the front end portion 21 on the front side. Wirings 25, 26, and 27 are provided on the upper surface side of the wiring board 2. These wires 25 to 27 are routed from the connection terminal portion 22 side to the outer edge of the recess 23, and are formed to extend in parallel along the length direction of the wiring substrate 2. Terminals 25a, 26a, and 27a are formed on the connection terminals 22 side of the wirings 25, 26, and 27, respectively. The wires 25, 26, and 27 are routed from the outer edge of the recess 23 to the bottom of the recess 23, and the ends of the wires form terminal portions 25b, 26b, and 27b, respectively.

  Next, the crystal unit 3 will be described with reference to FIGS. 6A and 6B showing the upper and lower surfaces, respectively. The crystal unit 3 includes a first crystal unit 3A and a second crystal unit 3B, and the first crystal unit 3A and the second crystal unit 3B are AT-cut common. The crystal piece 31 is provided. The crystal piece 31 is formed, for example, in a rectangular shape, and the left half and the right half are assigned to the first crystal oscillator 3A and the second crystal oscillator 3B, respectively, when the length direction of the crystal piece 31 is front and rear. Yes. Hereinafter, the left half region and the right half region of the crystal piece 31 will be referred to as a first vibration region 32a and a second vibration region 32b, respectively.

  An excitation electrode 33a is formed on the upper surface side of the first vibration region 32a, and an excitation electrode 33b is formed on the upper surface side of the second vibration region 32b. Excitation electrodes 34a and 34b are formed on the lower surfaces of the respective regions 32a and 32b. The excitation electrodes 33a and 33b formed on the upper surface side of the crystal piece 31 are disposed in the first and second vibration regions, respectively, and are formed in a substantially strip shape having a length of about 3.8 mm and a width of about 0.8 mm. . The excitation electrodes 33a and 33b are arranged in parallel with each other with an interval of about 0.4 mm. Each excitation electrode 33 is cut off two corners each located outside the strip shape arranged in the left and right. The excitation electrodes 34a and 34b on the lower surface side have the same shape, and are provided so as to face the excitation electrodes 33a and 33b on the upper surface side with the crystal piece 31 interposed therebetween.

  On the surface of the excitation electrode 33a provided in the first vibration region 32a, an adsorption layer (not shown) made of an antibody that selectively binds to an antigen as a sensing object is provided. On the other hand, an inhibition film (not shown) that inhibits the binding between the antigen and the excitation electrode 33b is provided on the surface of the excitation electrode 33b in the second vibration region 32b.

  One ends of the excitation electrodes 33 a and 33 b on the upper surface side are connected to each other, and the extraction electrode 35 is extended from the connection portion toward the periphery of the crystal piece 31. From the excitation electrodes 34 a and 34 b on the lower surface side of the crystal piece 31, extraction electrodes 36 a and 36 b are drawn outwardly so as to be orthogonal to the length direction of the crystal piece 31.

The crystal unit 3 is inserted into the recess 23 provided in the wiring board 2 described above. The quartz crystal resonator 3 is arranged so that the excitation electrodes 34a and 34b face the recess 23, and the extraction electrodes 35, 36a, and 36b overlap the terminal portions 25b, 26b, and 27b provided at the bottom of the recess 23, respectively. Connected to. The crystal resonator 3 is opposed to the bottom surface of the recess 23 through a gap by a conductive adhesive 37 used to connect the lead electrodes 35, 36a, 36b and the terminal portions 25b, 26b, 27b provided in the recess 23. To be held.
Incidentally, since the lead electrode of the crystal resonator is provided so as to overlap the wiring of the wiring board 2, in FIG. 3, the peripheral portion of the crystal piece 31 is shown as floating from the wiring board 2. The thickness of each electrode of the vibrator 3 and each wiring of the wiring board 2 is extremely small, and the crystal vibrator 3 is provided on the wiring board 2 in a substantially horizontal state.

Next, the flow path forming member 4 will be described. The flow path forming member 4 is made of, for example, PDMS (polydimethylsiloxane) having a high self-adsorption property. The flow path forming member 4 is formed in a square plate shape. In the flow path forming member, a through-hole serving as a cylindrical injection port 41 having a diameter of 1.5 mm in the thickness direction and a through-hole serving as a waste liquid port 42 are drilled side by side at an interval of about 4 mm. The
On the lower surface side of the flow path forming member, a frame portion 50 surrounding the injection port 41 and the waste liquid port 42 is formed to protrude downward at a height of 1 μm to 300 μm. As will be described later, the region surrounded by the frame portion 50 is closed by the quartz crystal resonator 3 on the lower side to become the supply flow path 10. The supply flow path 10 is provided in a straight line connecting the injection port 41 and the waste liquid port 42 with the shortest distance. The vicinity of the injection port 41 and the waste liquid port 42 is fan-shaped in a direction facing each other from the respective through holes. It is formed so as to spread, and the midstream portion is a linear flow path. That is, the supply channel is formed in a symmetrical hexagonal shape, and is provided so that the inlet 41 and the waste liquid port 42 are positioned at a pair of corners facing each other. The frame 50 is provided at a constant height, and the height of the supply flow path 10 is constant.

  The flow path forming member 4 is disposed so as to overlap from above the wiring board 2 on which the crystal resonator 3 is installed. The opening surface side of the supply flow path 10 is sealed by the crystal unit 3 to form a flow path space. The crystal resonator 3 and the frame 50 are in close contact with each other, so that the supply liquid is prevented from leaking along the surface of the crystal resonator 3. As shown in FIG. 7, the first crystal unit 3A and the second crystal unit 3B are arranged so as to divide the region of the supply channel 10 so as to equally divide the supply channel 10 in the width direction. Is done. The excitation electrodes 33a and 33b on the upper surface side provided in the first crystal unit 3A and the second crystal unit 3B are arranged so as to face the inner region of the supply channel 10 formed in the above-described hexagonal shape. The excitation electrodes 33a and 33b on the upper surface side are extended in the length direction of the supply flow path 10 and arranged so as to be lined up on the left and right.

  Before installing the flow path forming member 4 on the wiring board 2, the flow path forming member 4 is plasma-cleaned to activate the surface and remove organic substances on the surface. The plasma cleaning is performed in this manner because the inlet 41, the waste liquid port 42, the supply flow path 10 and the waste liquid pool 52 formed by being surrounded by the upper lid case 5 on the upper surface side of the flow path forming member 4 described later. Increase the affinity to facilitate the flow of the supply liquid inlet 41, the waste liquid port 42 and the waste liquid pool 52, the flow path forming member 4 and the wiring board 2, and the flow path forming member 4 and the upper lid case 5. The purpose is to prevent the supply liquid from leaking through these gaps. The flow path forming member 4 can be made of, for example, acrylic resin or quartz other than PDMS.

  Next, the upper lid case 5 will be described. A recess serving as an injection port 51 is provided in front of the upper lid case 5 on the upper surface side. The injection port 51 is provided with an inclination, and is configured so that the supply liquid dropped onto the injection port 51 is collected at the bottom. An air hole 53 penetrating the lower surface side is provided behind the upper lid case 5. On the lower surface side of the upper lid case 5, a hole 46 that penetrates the bottom of the injection port 51 is provided, and this hole 46 is provided at a position overlapping the injection port 41 of the flow path forming member 4. On the rear side of the lower surface of the upper lid case 5, a recess serving as a waste liquid pool 52 is provided, and the front side of the waste liquid pool 52 is provided at a position overlapping the waste liquid port 42 of the flow path forming member 4. Further, the back of the waste liquid pool is connected to the air hole 53. The waste liquid pool 52 is configured to have a larger volume than the injection port 51 so that a large amount of the supply liquid can be stored, and the waste liquid pool 52 is provided at a position lower than the injection port 51. A hook 54 that extends downward is provided on the front portion and the left and right side portions of the upper lid case 5.

  The upper lid case 5 is disposed so as to cover the flow path forming member 4 from above, and is locked to the wiring board 2 by a hook 54. The crystal resonator 3, the flow path forming member 4, and the upper lid case 5 are placed on the wiring board 2. Are stacked in this order. When the upper lid case 5 is laminated on the flow path forming member 4, the hole 46 provided in the injection port 51 is connected to the injection port 41 of the flow path forming member 4, and the lower surface side of the waste liquid pool 52 flows. It is closed by the upper surface of the path forming member 4 to form a space and is connected to the waste liquid port 42 of the flow path forming member 4. As a result, a series of flow paths are formed, which are the following: injection port 51 → injection port 41 → supply flow channel 10 → waste liquid port 42 → waste liquid pool 52

  The injection port 41 and the waste liquid port 42 are detachably provided with columnar filters 43 and 44 serving as capillary members. The filters 43 and 44 are porous bodies, and are configured by bundling straw-like chemical fibers made of cellulose, for example, and a large number of small holes are also formed on the side walls of the straw. The filter 43 is provided so as to protrude from the surface of the crystal unit 3 through the inlet 41 and the hole 46 and protrude to the bottom of the injection port 51, and the filter 44 passes through the waste liquid port 42 from the surface of the crystal unit 3, It is provided so as to protrude into the waste liquid pool 52.

  The filter 43 has a role of preventing clogging of the flow path by capturing foreign substances contained in the supply liquid in the holes. On the other hand, the size is such that fine particles can be sufficiently passed while holding the supply solution so as not to prevent the passage of the antigen contained in the sample solution. In addition, when viewed microscopically, the supply liquid that has passed through the filter 43 is in a finely divided state, and therefore, due to surface tension compared to the supply liquid that has been supplied to the inlet 41 without passing through the filter 43. The tendency to aggregate on the wiring board 2 is suppressed. Accordingly, the supply liquid that has passed through the filter 43 is promptly introduced into the supply flow path 10. The material of the filters 43 and 44 is not limited to cellulose, but it is preferable to select a material having a high affinity with the supply liquid in order to pass the supply liquid quickly. The filter 44 on the side of the waste liquid port 42 absorbs the supply liquid that has passed through the portion of the supply flow path 10 where the excitation electrode 33 is installed.

  When the connection terminal portion 22 of the sensing sensor 20 is inserted into the oscillation circuit unit 12, the wiring terminals 25a, 26a, and 27a of the connection terminal portion 22 correspond to the wiring terminals 25a to 27a in the oscillation circuit unit 12. The sensing device shown in FIG. 1 is configured by being electrically connected to the formed connection terminal portion. As shown in FIG. 8, the oscillation circuit unit 12 is provided with a first oscillation circuit 64 and a second oscillation circuit 65. The first oscillation circuit 64 connects the first crystal resonator 3A to the second oscillation circuit 64. The oscillation circuit 65 oscillates the second crystal resonator 3B.

  Next, each unit provided in the main body unit 13 constituting the sensing device will be described. A switch unit 66 is provided following the oscillation circuits 64 and 65, and the frequency signal from the two oscillation circuits 64 and 65 is taken into the data processing unit 67 by the switch unit 66. The data processing unit 67 digitally processes a frequency signal as an input signal, and oscillates by the first oscillation circuit 64. The time series data of the oscillation frequency “F1” and the oscillation frequency “F2” from the second oscillation circuit 64 are obtained. ”Is acquired. Further, the difference “F1−F2” of each time series data is calculated, the time series data of the difference data is acquired, and the graph of “F1−F2” is displayed on the display unit 16.

  The operation of the sensing sensor 20 according to the embodiment of the present invention will be described. In addition, in the supply liquid, a liquid for making the surroundings of the crystal unit 3 into a liquid atmosphere without including the sensing object is referred to as a reference liquid, and the sensing sensor 20 is used to determine whether or not the sensing object is included. The liquid to be supplied is referred to as a sample liquid. In this example, the reference solution is physiological saline, and the sample solution is obtained by diluting a human nasal wiping solution with physiological saline. In FIG. 9 to FIG. 11, the reference liquid is indicated by a number of points, and the sample liquid is indicated by oblique lines.

  First, when the measuring instrument 11 is activated and the sensing sensor 20 is inserted into the oscillation circuit unit 12, the crystal resonators 3A and 3B oscillate, and the frequency signals F1 and F2 corresponding to the respective frequencies are taken out. These frequency signals are time-divided and taken into the data processing unit 67, and after A / D conversion, each digital value is subjected to signal processing. The frequencies “F1, F2” are extracted from the frequency signals of the two channels and stored in a memory (not shown), and “F1-F2” is calculated based on the stored “F1, F2” and stored in the memory. The stored operation is continued. Further, the above-described graph is displayed on the display unit 16, and the change of the frequency difference “F1-F2” is displayed in real time.

  Next, as shown in FIG. 9A, the user drops, for example, a reference solution (physiological saline) with a dropper into the injection port 51 provided in the injection port 41 of the sensing sensor 20. In the detection sensor 20 according to the embodiment of the present invention, in addition to installing the injection port 51 at a position higher than the waste liquid pool 52, the injection port 41 and the waste liquid port 42 are configured to be thin, Filters 43 and 44 are inserted into the filter. Therefore, it is circulated by the capillarity of the filters 43 and 44 provided in the inlet 41 and the waste liquid port 42 and the siphon effect using the height difference between the injection port 51 and the waste liquid pool 52, and the supply of the supply liquid to the supply flow path 10 and Discharge from the supply flow path 10 is performed.

  The reference liquid is absorbed by the filter 43 as shown in FIGS. 9B and 9C, descends downward in the filter 43 due to gravity, and is supplied to the supply channel 10 by capillary action. As shown in FIGS. 10A to 10C, the supply channel 10 is configured such that the left and right dimensions (widths) gradually increase from the inlet 41 toward the downstream direction, and the reference liquid is a channel. It flows in a fan shape from the inlet 41 along the shape. When the reference liquid flows, the environmental atmosphere of the vibration regions 32a and 32b of the crystal resonator 3 provided in the supply flow path 10 changes from the gas phase to the liquid phase, and the output frequency of each channel increases due to an increase in resistance based on the viscosity of the liquid. F1 and F2 decrease.

  Excitation electrodes 33a and 33b provided on the surface on the supply flow path 10 side and in contact with the supply liquid are arranged in the left-right direction with respect to the direction in which the reference liquid flows. Therefore, the reference liquid flows simultaneously and similarly to the respective excitation electrodes 33a and 33b, and the elements other than the load of the sensing object are configured to be as equal as possible between the respective excitation electrodes 33a and 33b. It can function as a highly reliable reference.

  When the size of the sensor 20 is reduced, the supply flow path 10 is narrowed, and the size of the excitation electrodes 33a and 33b to be installed is reduced. In particular, when the excitation electrodes 33a and 33b are arranged side by side with respect to the supply flow path 10, the excitation electrodes 33a and 33b become thin, and the CI value of the crystal resonator 3 increases and is stable. In addition, there is a possibility that measurement cannot be performed in the case of a sample solution having a high viscosity. In the above-described embodiment, the supply flow path 10 is configured to expand in a fan shape from the inlet 41, and the width of the midstream region of the supply flow path 10 is increased. For this reason, since the flow rate gradually increases, bubbles are not generated in the supply flow path 10 due to a rapid change in the flow rate. Furthermore, the shape of each excitation electrode 33a, 33b is not rectangular, but two corners outside the parallel excitation electrodes 33a, 33b are cut off. Therefore, the excitation electrodes 33a and 33b can be arranged up to a position where a blind spot is formed in a rectangular excitation electrode, and the area can be increased as compared with the rectangular excitation electrode.

  Further, in the embodiment of the present invention, the rectangular quartz crystal piece 31 is arranged so as to extend in the length direction with respect to the flow channel direction of the supply flow channel 10, and the first crystal resonator 3 </ b> A and the second crystal resonator 3 </ b> A. The crystal resonators 3B are arranged side by side in the width direction. Therefore, it is not necessary to make the width of the supply flow path 10 wider than in the case where the crystal resonators having the same area are arranged so as to extend in the width direction of the supply flow path 10. When the flow path is wide, there is a difference in flow velocity between the center and the end of the flow path, so that bubbles are easily generated in the flow path, and downsizing of the sensing sensor 20 is limited.

  The reference liquid flowing into the supply flow path 10 is absorbed by the filter 44 provided in the waste liquid port 42 as shown in FIG. 11A, and the capillary phenomenon of the filter 44 and the height difference between the injection port 51 and the waste liquid pool 52. Due to the siphon effect, the liquid outlet 42 is raised. When the supply liquid rises to the upper surface of the flow path forming member 4, it flows out into the waste liquid pool 52 and is stored in the waste liquid pool 52 (FIG. 11B). While the reference liquid contained in the filter 43 on the inlet 41 side decreases, the reference liquid contained in the waste liquid pool 52 and the filter 44 on the waste liquid port 42 side increases, and the water pressure of the filter 44 on the waste liquid port 42 side increases. Then, the movement of the reference liquid from the injection port 41 to the waste liquid port 42 is stopped.

  Subsequently, the sample solution is dropped into the injection port 51. As shown in FIG. 11C, the sample liquid is absorbed by the filter 43 in the same manner as the reference liquid, and moves downward through the filter 43 due to gravity, so that the reference liquid remaining on the filter 43 is pushed downstream. All of the reference liquid flows through the supply flow path 10 and travels toward the waste liquid port 42. Then, the sample solution enters the supply channel 10 by capillary action of the filter 43 like the reference solution and flows so as to spread along the outer edge of the supply channel 10, and the liquid phase in the supply channel 10 is the reference solution. Is replaced with the sample solution.

  When the sample object contains a sensing object, the first crystal resonator 3A adsorbs the antigen by the antigen-antibody reaction, so that a mass load is applied and the oscillation frequency changes. On the other hand, in the second crystal unit 3B, no mass load is caused by the adsorption of the antigen. When the sample liquid contains an antigen, in the first crystal resonator 3A, in addition to the frequency changing due to the temperature and viscosity of the sample liquid, the antigen is adsorbed to the adsorption film by the antigen-antibody reaction, and due to the mass load effect The value of the frequency “F1” further decreases. On the other hand, a frequency “F2” that changes in accordance with the temperature and viscosity of the sample solution is output from the channel 2 on the second crystal resonator 3B side. As a result of such a frequency change, the frequency “F1-F2” decreases. The sample liquid flows from the supply channel 10 to the waste liquid port 42 and is stored in the waste liquid pool 52. When the amount of liquid in the waste liquid pool 52 increases and the water pressure increases, the movement of the sample liquid from the inlet 41 stops.

  When the sample solution does not contain the antigen, it flows in the same way as when it contains the antigen, but the above-described antigen-antibody reaction does not occur in the first quartz oscillator 3A, and the temperature of the sample solution is Since the frequencies “F1” and “F2” that change according to the viscosity are extracted, the frequency difference hardly changes. Then, a difference value a−b between the value “a” of “F1−F2” from a certain time t1 to t2 and the value “b” of “F1−F2” after time t2 is calculated, and this difference value ab is a predetermined allowable value. If it falls within the value, it is determined that there is no antigen in the sample solution, and if the difference value a−b exceeds the allowable value, it is determined that the antigen is present in the sample solution.

  As described above, the supply flow path 10 is configured such that the inlet 41 and the waste liquid inlet 42 are narrow, and the width of the portion where the excitation electrode 33 is installed is widened. However, when the width of the supply flow path 10 is suddenly changed, a difference occurs in the flow rate of the supply liquid between the narrow portion and the wide portion. When there is a large difference in flow rate, the solution is separated and bubbles are likely to be generated in the supply liquid. When bubbles are generated, the supply liquid does not flow uniformly in the supply flow path 10 and there is an error in detection. Arise. Therefore, by configuring the supply channel 10 so that the central angle of the supply channel 10 spreading in a fan shape from the inlet 41 does not increase, the change in the flow rate in the supply channel 10 may be reduced to suppress the generation of bubbles. In order to reduce the change in the flow velocity in the supply flow path 10 while sufficiently widening the supply flow path 10, it is desirable that the central angle be set at an angle of 50 to 65 degrees. Further, R is provided at four corners on the side of the supply channel 10 configured in a hexagonal shape so as to reduce the resistance applied to the supply liquid flowing through the supply channel 10, so that bubbles are supplied to the supply channel 10. You may comprise so that it may remain in the corner | angular part. In addition, the height of the supply channel 10 utilizing the capillary phenomenon is as small as 1 to 300 μm, and since the ratio of the sensing object in the sample liquid in the channel is large, detection with high sensitivity is possible. it can.

  According to the sensing sensor 20 according to the above-described embodiment, the sample liquid is supplied to the flow path facing the piezoelectric vibrator 3 by capillary action. Therefore, although it is a flow cell type sensor, a pump for circulating the sample liquid is not necessary. In addition, since the supply channel 10 is configured so that the left and right dimensions (widths) gradually increase from the inlet toward the downstream direction, the flow velocity in the supply channel 10 does not change abruptly, so Air bubbles are less likely to occur in Therefore, it is possible to provide the detection sensor 20 that can perform highly reliable measurement while being a small detection sensor 20.

[Other embodiments]
In the detection sensor 20 of the present invention, the injection port 41 and the waste liquid port 42 may be provided outside the region of the crystal unit 3. For example, as shown in FIG. 12, the area of the recess 23 and the crystal unit 3 provided in the wiring board 2 is configured to be narrower than the area of the projection area of the supply flow path 10, and the flow path wall 50 of the supply flow path 10 is wired. Adhere to the substrate 2. A square plate-like crystal resonator 3 is fitted into a recess 23 provided in the wiring board 2, and the crystal resonator 3 is electrically connected to the wirings 25, 26, 27 routed into the recess 23 and the lower surface side of the crystal resonator 3. Connect. The injection port 41 and the waste liquid port 42 are provided so as to be located outside the region of the crystal resonator 3, and the filters 43 and 44 extended from the injection port 41 and the waste liquid port 42 are configured to be in contact with the wiring board 2. . The periphery of the crystal unit 3 is blocked by a seal member 47, and the supply liquid does not circulate to the lower surface side of the crystal unit 3 and flows on the surface of the crystal unit 3. The excitation electrodes 33a and 33b are arranged so as to be lined up on the left and right with the front-rear direction as the flow path direction, and are provided in a strip shape. The flow path forming member 4 is bonded to the wiring board without passing through the crystal resonator 3, and the flow path wall 50 provided in the flow path forming member 4 is disposed so as to surround the crystal resonator 3 and the recess 23. And bonded to the wiring board 2. The present invention can also be applied when such a configuration is used.

DESCRIPTION OF SYMBOLS 1 Sensing apparatus 2 Wiring board 3 Crystal oscillator 4 Channel formation member 5 Upper cover case 10 Supply channel 11 Measuring device 12 Oscillation circuit unit 20 Sensing sensor 22 Connection terminal part 31 Crystal piece 33, 34 Excitation electrode 41 Inlet 42 Waste liquid port

Claims (3)

A wiring board having a connection terminal portion connected to a measuring instrument for measuring an oscillation frequency and having a recess formed on one surface side;
Excitation electrodes are respectively formed on a common piezoelectric piece fixed to the wiring board so as to close the recess, and each excitation electrode is electrically connected to the connection terminal portion. A piezoelectric vibrator;
In order to form a flow path between the first piezoelectric vibrator and the area on the one surface side of the wiring board including the second piezoelectric vibrator, a sample is provided in the flow path so as to cover the area. A flow path forming member in which an injection port for injecting a liquid and a waste liquid port for discharging the injected sample liquid are formed in front and back;
An adsorption layer provided on the excitation electrode on the flow path forming member side in the first piezoelectric vibrator and adsorbing a sensing object in the sample liquid,
The first excitation electrode and the second excitation electrode are arranged side by side in the flow path,
The flow path forming member circulates the sample liquid from the injection port to the waste liquid port via the one surface of both piezoelectric vibrators by capillary action, and the width of the flow channel increases in the downstream direction from the injection port. Sensing sensor characterized by comprising.   2. The sensor according to claim 1, wherein the flow path forming member is configured such that after the width of the flow path is increased, the width of the flow path is further reduced toward the waste liquid port.   3. The sensor according to claim 1, wherein the flow path forming member has an opening angle of 50 degrees to 65 degrees in a downstream direction from the injection port.

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