JP6180198B2 - Sensing sensor - Google Patents

Description

  The present invention relates to a sensing sensor for sensing a sensing object using a crystal resonator 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 symmetric substance in a sample fluid, for example, a minute amount of protein in blood or serum, a sensor using a QCM (Quartz Crystal Microbalance) as shown in Patent Document 1, for example, is shown. QCM uses a quartz oscillator that has an adsorption film on the surface of the excitation electrode that adsorbs the sensing object by antigen-antibody reaction. The mass load caused by the adsorption of the sensing object in the sample solution changes the frequency of the crystal oscillator. This is to quantify the sensing object. Using this basic principle, it is possible to apply to simple measurement used for diagnosis and food inspection in the medical field.

In recent years, in order to increase the sensitivity of low-concentration samples, downsizing of the sensor is required. In the sensor, a micro fluid chip is used to form a very narrow reaction space, and the antigen-antibody reaction is carried out. However, since the capacity of the reaction space is reduced by downsizing the sensor, a small amount of sample is used. This is because the electrode surface can pass through.
However, when the size of the sensing sensor is reduced and the reaction space is reduced, it is necessary to reduce the area of the excitation electrode formed on the crystal resonator. When the area of the excitation electrode is narrowed, the CI value of the crystal resonator increases, and the oscillation frequency becomes unstable. For this reason, there is a problem that the reliability of the measurement accuracy of the sensing sensor is lowered.

JP 2009-206792 A

  The present invention has been made under such circumstances, and an object of the present invention is to perform a highly reliable measurement by reducing the CI value in a sensing sensor that measures a sensing object in a sample liquid. It is an object of the present invention to provide a sensing sensor capable of

The sensing sensor of the present invention is provided on one side of the crystal piece, and a common electrode for excitation that is set to the ground potential during oscillation,
The crystal pieces are provided on the other surface side of the crystal piece so as to be separated from each other and to face the common electrode, and each outer edge protrudes outward from a region facing the common electrode over the entire circumference of the common electrode A first divided electrode and a second divided electrode formed as described above,
An adsorption layer formed on a surface of the common electrode and facing one of the first divided electrode and the second divided electrode, and adsorbs a sensing object in a sample solution;
A connection terminal portion for connecting each of the common electrode, the first divided electrode, and the second divided electrode to the oscillation circuit is provided, and a space is formed in a region facing the first divided electrode and the second divided electrode. A wiring board on which the crystal piece is fixed,
The common electrode is accommodated in a space serving as a sample liquid supply flow path formed above the common electrode by a flow path forming member, and an outer edge of each of the first divided electrode and the second divided electrode is It is located outside the region facing the space that serves as the sample liquid supply channel .

The sensing sensor of the present invention further includes a flow path forming member for forming a space forming a supply flow path for the sample liquid above the common electrode,
The flow path forming member is formed with a sample liquid inlet and a sample liquid outlet on one end side and the other end side, respectively.
When the other end side is viewed from one end side of the flow path forming member, the left edge side of the first divided electrode located on the left side and the right edge side of the second divided electrode located on the right side face the space. It may be characterized by protruding from the area. Furthermore, the common electrode may include a region facing the first divided electrode and a region facing the second divided electrode, which are spaced apart from each other on the left and right.

  In a detection sensor using a crystal resonator, if the excitation electrode is designed too close to the edge of the supply flow path, there is a greater concern that the flow path forming member will contact the common electrode during assembly. When the flow path forming member comes into contact with the excitation electrode, the oscillation is disturbed, or the area of the adsorption layer that can adsorb the sensing object in the sample liquid changes, and the amount of decrease in frequency due to the adsorption of the object changes. Contact must not occur. Accordingly, the present invention provides a common electrode on one side through which a sample solution flows in a crystal piece and a first divided electrode and a second divided electrode on the other side, and the divided electrode is provided in the projection region of the supply channel (space). It is configured to protrude to the outside. For this reason, when viewed from the top of the crystal unit, the divided electrode is formed from the outer edge of the common electrode to the edge of the supply flow path, so that the divided electrode exists in a region slightly protruding from the common electrode. . Accordingly, since the slightly protruding region becomes a vibration region, if the flow path of the sample solution becomes large, the ratio of the area of the vibration region increases, which contributes to the reduction of the CI value.

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 longitudinal side view of the sensing sensor, and (b) A longitudinal side view in which a crystal resonator and a supply channel are enlarged. It is the disassembled perspective view which showed the upper surface side of each part of a detection sensor. It is the disassembled perspective view which showed the lower surface side of each part of a sensing 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 (a) upper surface side of the state which installed the said crystal oscillator in the supply flow path, and (b) lower surface side. 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 a top view which shows the (a) upper surface side of the state which installed the crystal oscillator based on 2nd Embodiment in the supply flow path, and (b) lower surface side.

  A sensing device using a sensing sensor according to an embodiment of the present invention will be described below. This sensing device uses a microfluidic chip, and can detect the presence or absence of an antigen such as a virus in a sample liquid obtained from, for example, a wiping liquid of a human nasal cavity, and determine the presence or absence of a human virus infection. It is configured as follows. As shown in the external perspective view of FIG. 1, the sensing device includes a measuring device 10 including an oscillation circuit unit 11 and a main body 12, and a detection sensor 1 detachably connected to the oscillation circuit unit 11 of the measuring device 10. It is equipped with. The oscillation circuit unit 11 is connected to the main body 12 via, for example, a coaxial cable 13. A display unit 81 configured by, for example, a liquid crystal display screen is provided on the front surface of the main body unit 12, and the display unit 81 is, for example, a measurement result such as an output frequency of the oscillation circuit unit 11 or a change in frequency, or a virus. The presence / absence of detection is displayed.

  Next, the configuration of the sensing sensor 1 will be described. FIG. 2 is a perspective view of the sensing sensor 1, and FIG. 3 is a longitudinal side view of the sensing sensor 1. 4 and 5 are exploded perspective views showing the upper surface side and the lower surface side of each part of the sensing sensor 1, respectively. This will be described with reference to FIGS. The sensing sensor 1 includes a wiring substrate 2, a crystal resonator 3, a flow path forming member 4, and an upper lid case 5 that are stacked from below. The wiring board 2 is, for example, a substantially rectangular board. When the length direction is front and rear, the wiring board 2 is a connection terminal portion 21 to be inserted into the oscillation circuit unit 11 on the rear side. For example, a circular through hole 22 is provided on the front side of the wiring board 2. Wirings 25, 26, 27 extending in the length direction of the wiring substrate 2 are provided on the upper surface of the wiring substrate 2, and each of the wirings 25, 26, 27 extends from the connection terminal portion 21 to the outer edge of the through hole 22. The electrode pads 25a, 26a, and 27a are formed on the outer edges of the through holes 22, respectively, and the terminal portions 25b, 26b, and 27b are formed on the connection terminal portion 21, respectively. A pad 28 is formed of a conductor at a position facing the electrode pad 27a via the through hole 22.

  Next, the crystal resonator 3 will be described with reference to FIGS. 6A and 6B showing the upper and lower surfaces, respectively. The crystal unit 3 is configured by a disk-shaped crystal piece 30 having a diameter of several millimeters, for example, formed by AT cut. A common electrode 31 is provided on the surface side that is one surface side of the crystal unit 3, and first and second electrode portions 32 and 33 that are excitation electrodes are provided. The first and second electrode portions 32 and 33 are made of, for example, a laminate of Cr and Au, and are arranged so as to be aligned in the left and right direction in the width direction and extend in the front-rear direction. On the back surface side that is the other surface side of the crystal unit 3, first and second divided electrodes 34 and 35 that are excitation electrodes are provided. The first and second divided electrodes 34 and 35 are opposed to the first and second electrode portions 32 and 33 over the entire circumference of the first and second electrode portions 32 and 33, respectively. It is formed so as to protrude from the region. The first and second divided electrodes 34 and 35 are arranged so as to be separated from each other. The regions sandwiched between the first and second electrode portions 32 and 33 of the crystal resonator 3 and the first and second divided electrodes 34 and 35, respectively, are first and second vibration regions 61, 62. These first and second vibration regions 61 and 62 vibrate independently of each other.

  The first and second electrode portions 32, 33 are connected at one end in the length direction to form the common electrode 31, and the extraction electrode 38 is extracted in the peripheral direction of the crystal piece 30. The lead electrode 38 is routed to the back surface of the crystal piece 30 through the front and side surfaces of the crystal piece 30, and a terminal portion 38 a is formed at the peripheral portion on the back surface side of the crystal piece 30.

In the first divided electrode 34 and the second divided electrode 35, lead electrodes 36 and 37 are drawn in directions opposite to directions facing each other, and each lead electrode 36 and 37 is a crystal piece. Terminal portions 36a and 37a are formed at the peripheral portion on the back surface side of 30. Note that each of the extraction electrodes 36, 37, and 38 is sufficiently thin and thus excluded from the vibration region. The lead electrodes 36, 37, and 38 are electrodes extended from a part of the first and second electrode portions 32 and 33 and the first and second divided electrodes 34 and 35, and are oscillated through wiring. The electrode for connecting to.
The first electrode portion 32 is provided with an adsorption film (not shown) made of an antibody that selectively binds to a sensing object such as an antigen such as a virus. On the other hand, on the surface of the second electrode part 33, an inhibitory film that inhibits the binding between the virus and the second electrode part 33 is provided.

  In the quartz crystal resonator 3, the first and second divided electrodes 34 and 35 face the through hole 22 of the wiring board 2, and terminal portions 36 a, 37 a, and 38 a are respectively corresponding electrode pads provided on the wiring board 2. 25a, 26a and 27a are arranged so as to be placed on the pad 28. The terminal portions 36a, 37a, and 38a are bonded to the electrode pads 25a, 26a, and 27a by the conductive adhesive 7, and the crystal resonator 3 is held. In FIG. 3, the peripheral portion of the crystal piece 30 is shown as floating from the wiring board 2, but actually, the first and second electrode portions 32, 33, first and second of the crystal resonator 3 are shown. The thicknesses of the second divided electrodes 34 and 35, the wirings 25, 26 and 27 on the wiring board 2, the electrode pads 25a, 26a and 27a, and the pad 28 are extremely small, and the conductive adhesive 7 is very small. Therefore, the crystal unit 3 is fixed to 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 formed in a rectangular plate shape by, for example, PDMS (polydimethylsiloxane). On the lower surface side of the flow path forming member 4, a stepped portion 46 is formed along these outer shapes so that the crystal resonator 3 and the wirings 25, 26, 27 are accommodated. The stepped portion 46 is provided with through-holes that penetrate in the thickness direction and serve as the inlet 42 and the waste liquid port 43 so as to be lined up at two positions in the front and rear. In addition, a frame is disposed on the step portion 46 so as to surround the inlet 42 and the waste liquid port 43, thereby forming a frame portion 41. The frame part 41 is formed in a hexagonal shape, and is provided so that the injection port 42 and the waste liquid port 43 are arranged at two opposite corners.

  The flow path forming member 4 is superimposed on the front side of the wiring board 2 from above the crystal resonator 3. When the flow path forming member 4 is overlaid, the frame portion 41 comes into contact with the crystal resonator 3, thereby forming a space serving as the supply flow path 40 having the crystal resonator 3 as a bottom surface. At that time, as shown in FIG. 7, the first and second electrode portions 32, 33 are placed inside the frame portion 41 and are arranged at positions away from the frame portion 41. At that time, the right edge side of the first divided electrode 34 disposed on the right side of the crystal piece and the left edge side of the second divided electrode 35 are located outside the opposing region of the supply flow path 40.

  Further, since the supply flow path 40 is configured to flow from the front to the rear of the detection sensor 1, the first and second vibration regions 61 and 62 are arranged side by side. For this reason, the reference liquid flows simultaneously and similarly to the first and second vibration regions 61 and 62, and the elements other than the load of the sensing object are made as equal as possible between the vibration regions 61 and 62. And can function as a highly reliable reference.

  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 so that the supply liquid dropped onto the injection port 51 is collected at the bottom. A through hole 52 is provided at the bottom of the injection port 51, and the hole 52 is provided at a position corresponding to the injection port 42 of the flow path forming member 4. On the rear side of the lower surface of the upper lid case 5, a recess that becomes a waste liquid pool 53 is provided, and the front side of the waste liquid pool 53 is provided at a position that overlaps the waste liquid port of the flow path forming member 4. Further, the waste liquid pool 53 is provided with an air hole 54 penetrating to the upper surface side of the upper lid case 5. The waste liquid reservoir 53 is configured to have a larger volume than the injection port 51 so that a large amount of supply liquid can be stored. The waste liquid reservoir is provided at a position lower than the injection port 51. The upper lid case 5 is provided with a hook 55.

  The upper lid case 5 is stacked above the flow path forming member 4 disposed on the wiring board 2. The upper lid case is laminated on the wiring board 2 in the order of the crystal resonator 3, the flow path forming member 4, and the upper lid case 5 by the hook 55 being locked to the wiring board 2. When the upper lid case 5 is stacked on the flow path forming member 4, the hole 52 is connected to the inlet 42 on the flow path forming member 4 side. Further, the bottom surface side of the waste liquid pool 53 is closed by the upper surface of the flow path forming member 4 to form a space, and the waste liquid pool 53 and the waste liquid port 43 are connected. As a result, a series of flow paths are formed, which are the injection port 51 → the injection port 42 → the supply flow path 40 → the waste liquid port 43 → the waste liquid pool 53.

  The inlet 42 and the waste liquid port 43 are detachably provided with columnar filters 44 and 45 serving as capillary members. The filter 44 is provided so as to protrude from the surface of the crystal resonator 3 through the injection port 42 and the hole 52 to the bottom of the injection port 51. The filter 45 provided in the waste liquid port 43 is provided so that the lower end thereof is the height of the ceiling of the supply flow path 40 and the front end thereof protrudes into the waste liquid pool 53.

  When the connection terminal portion 21 of the sensing sensor 1 is inserted into the oscillation circuit unit 11, the terminals 25a, 26a, 27a of the connection terminal portion 21 correspond to these terminals 25a, 26a, 27a in the oscillation circuit unit 11. The sensing device is configured by being electrically connected to a connection terminal portion (not shown) formed as described above. As shown in FIG. 8, the oscillation circuit unit 11 is provided with a first oscillation circuit 71 and a second oscillation circuit 72 configured by, for example, a Colpitts circuit, and the first oscillation circuit 71 has a first oscillation circuit. In the region 61, the second oscillation circuit 72 is configured to oscillate the second vibration region 62, respectively. The terminal 27a is connected so as to have a ground potential during oscillation.

  The main body unit 12 includes a switch unit 82 and a data processing unit 83. The output sides of the first and second oscillation circuits 71 and 72 provided in the oscillation circuit unit 11 are connected to the main body portion 12 via the coaxial cable 13, and the switch portion 82 provided in the main body portion 12. Connected. The data processing unit 83 provided at the subsequent stage of the switch unit 82 performs digital processing of the frequency signal that is an input signal, and outputs time-series data of the oscillation frequency “F1” output from the first oscillation circuit 71 and the second The time series data of the oscillation frequency “F2” output by the oscillation circuit 72 is acquired. In the sensing device of the present invention, the switch unit 82 alternately switches the channel 1 connected to the data processing unit 83 and the first oscillation circuit 71 and the channel 2 connected to the data processing unit 83 and the second oscillation circuit 72. By performing switched intermittent oscillation, interference between the two vibration regions 61 and 62 of the sensing sensor 1 is avoided, and a stable frequency signal can be acquired. These frequency signals are time-divided, for example, and taken into the data processing unit 83. The data processing unit 83 calculates a frequency signal as, for example, a digital value, performs arithmetic processing based on the time-division data of the calculated digital value, and displays a calculation result such as the presence or absence of an antigen on the display unit 81, for example. .

  The operation of the sensing sensor 1 according to the embodiment of the present invention will be described. In the following description, the supply liquid for making the surroundings of the crystal unit 3 a liquid atmosphere without including the sensing object is referred to as a reference liquid, and the object for determining whether or not the sensing object is included. The supply liquid supplied to the sensing sensor 1 is referred to as a sample liquid. In this example, the reference solution uses physiological saline, and the sample solution uses a human nasal wiping solution diluted with physiological saline.

When the sensor 1 is inserted into the oscillation circuit unit 11 and the measuring instrument 10 is activated, the vibration regions 61 and 62 of the crystal resonator 3 are oscillated, and the frequency signals F1 and F2 corresponding to the respective frequency signals are taken out.
Next, as shown in FIG. 9A, the user drops, for example, a reference solution (physiological saline) into the injection port 51 with a dropper. In FIGS. 9 and 10, the reference liquid shows the dot density low, and the sample liquid shows the dot density high. In the detection sensor 1 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 53, the injection port 42 and the waste liquid port 43 are configured to be thin, Inserts filters 44 and 45. Therefore, it is circulated by the capillarity of the filters 44 and 45 provided at 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 53, and the supply of the supply liquid to the supply flow path 40 and Discharge from the supply flow path 40 is performed.

  The reference liquid dropped into the injection port 51 is absorbed by the filter 44 provided at the injection port 42 as shown in FIG. 9 (b), descends the filter 44 by gravity, and is shown in FIG. 9 (c). Thus, it is supplied into the supply flow path 40. At this time, the supply liquid (reference liquid) 70 flows along the shape of the supply flow path 40 so as to spread the entire bottom surface of the supply flow path 40 in a fan shape. When the reference liquid flows, the environmental atmosphere of the first and second vibration regions 61 and 62 of the crystal unit 3 provided in the supply flow path 40 changes from the gas phase to the liquid phase, and the increase in the viscosity of the liquid causes each channel to change. The output frequencies F1 and F2 are reduced.

  As shown in FIG. 10A, the reference liquid that has flowed into the supply flow path 40 is absorbed by the filter 44 provided at the waste liquid port 42, rises up the waste liquid port 43, and is stored in the waste liquid pool 53 (FIG. 10). (B)). Subsequently, the sample solution is dropped into the injection port 51. As shown in FIG. 10C, the sample solution flows to the supply channel 40 in the same manner as the reference solution. As a result, the reference liquid remaining in the flow path is pushed downstream, and the liquid phase in the supply flow path 40 is replaced with the sample liquid from the reference liquid.

When the supply channel 40 is filled with the sample solution and the sample solution contains an antigen to be sensed, the antigen is adsorbed to the antibody provided in the adsorption layer by an antigen-antibody reaction. Is done. The adsorption layer is provided in the first electrode part 32, and the mass of the antigen adsorbed on the adsorption layer is loaded on the mass of the electrode in the region.
When the sample liquid contains an antigen, the frequency “F1” extracted from the first vibration region 61 is changed by the temperature and viscosity of the sample liquid, and the antigen is adsorbed by the antigen-antibody reaction. Adsorbed on the film, the frequency is further reduced by the mass load effect. On the other hand, from the channel 2 connected to the second vibration region 62, a frequency “F2” that changes according to the temperature and viscosity of the sample liquid is extracted. As a result of such a frequency change, the frequency “F1-F2” decreases. Thereafter, as shown in FIG. 10D, the sample liquid flows from the supply channel 40 to the waste liquid port 43 and is stored in the waste liquid pool 53. When the amount of the waste liquid pool 53 increases and the water pressure increases, the movement of the sample liquid from the inlet 42 stops. When the sample liquid does not contain an antigen, the sample liquid flows in the same manner as when the antigen is contained. However, in the first vibration region, the mass load due to the antigen-antibody reaction does not occur. Since the frequencies “F1” and “F2” that change according to the temperature and viscosity of the sample solution are taken out from the channel 1 and the channel 2, the frequency difference hardly changes.

  The CI value indicated by the crystal resonator 3 can be suppressed by increasing the excitation electrode provided in the crystal resonator 3. In the sensing sensor 1, the flow path forming member 4 is provided so as to contact the crystal resonator 3, and the first and second electrode portions 32 and 33 are arranged side by side in the supply flow path 41. When the first and second electrode portions 32 and 33 of the crystal unit 3 come into contact with the frame portion 41 forming the supply flow path 40, the CI value may increase. In addition, the area in contact with the supply liquid changes, and the temperature and viscosity of the sample liquid or the change in frequency due to the antigen-antibody reaction is disturbed. Therefore, the first and second electrode portions 32 and 33 are limited to a size that can be accommodated in the supply flow path 40. On the other hand, since the other surface side of the crystal unit 3 is not in contact with the flow path forming member 4, the flow path forming member 4 does not contact even if the first and second divided electrodes 34 and 35 are provided large. In the above-described crystal resonator 3, the first and second divided electrodes 34 and 35 opposite to the supply flow path 40 side are widely provided.

  When the divided electrode of the crystal piece 30 is provided larger than the common electrode, the region sandwiched between the divided electrode and the common electrode vibrates greatly. At the same time, the region outside the common electrode and the region where the divided electrode is provided also vibrates slightly, and tries to vibrate together with the region sandwiched between the divided electrode and the common electrode. Therefore, in the crystal resonator 3 according to the above-described embodiment, the first and second divided electrodes 34 and 35 of the crystal resonator 3 are formed, and the first and second electrode portions 32 and 33 are provided, respectively. The region that has not been sought to vibrate integrally with the first and second vibration regions 61 and 62.

  In the region outside the supply flow path 40, vibration energy leaks due to contact with the frame portion 41, but the vibration is easily stabilized by the amount of the region that is inside the supply flow path 40 and performs slight vibration. . Therefore, the CI value indicated by the above-described crystal resonator 3 is lower than that in the case where the first and second divided electrodes having the same width as the first and second electrode portions 32 and 33 are provided. Therefore, the oscillation frequency becomes stable, which contributes to the reduction of the CI value. When the space volume of the supply flow path 40 becomes small, the ratio that occupies the area of the vibration region becomes large, so that the effect becomes larger.

  According to the above-described embodiment, in the crystal piece provided in the sensing sensor 1, the common electrode 31 is provided on one side through which the sample solution flows, and the first divided electrode and the second divided electrodes 34, 35 are provided on the other side. The first divided electrode and the second divided electrode 34 and 35 are configured to protrude outside the projection region of the supply flow path 40 (space). Therefore, when viewed from above the crystal resonator 3, the first and second divided electrodes 34, 35 are formed so as to protrude from the outer edge of the common electrode 31 to the edge of the supply flow path 40. The first and second divided electrodes 34 and 35 exist in the protruding area. Accordingly, since the slightly protruding region becomes a vibration region, if the flow path of the sample solution becomes large, the ratio of the area of the vibration region increases, which contributes to the reduction of the CI value.

[Second Embodiment]
As the sensing sensor according to the second embodiment, the excitation electrode on one side of the crystal unit 39 may be configured as the common electrode 9 as shown in FIG. A region between the common electrode 9 and the first divided electrode 34 is a first vibration region 61, and a region between the common electrode 9 and the second divided electrode 35 is a second vibration region 62. Become. The first and second vibration regions 61 and 62 are provided so as to be accommodated in the supply flow path 40, respectively. Further, an adsorption film (not shown) made of an antibody is provided, for example, in the first vibration region 61 on the surface of the common electrode 9, while the surface of the second vibration region 62 inhibits the binding between the virus and the common electrode 9. An inhibitory membrane is provided. Also in this case, since the excitation electrode provided in the crystal unit 39 becomes large, the CI value can be suppressed. Therefore, the accuracy of the sensing sensor 1 is increased.

DESCRIPTION OF SYMBOLS 1 Sensing sensor 2 Wiring board 3, 39 Crystal oscillator 4 Flow path formation member 9, 31 Common electrode 10 Measuring device 21 Connection terminal part 30 Crystal piece 32 1st electrode part 33 2nd electrode part 34 1st division | segmentation electrode 35 Second divided electrode 40 Supply channel 42 Inlet 43 Waste liquid port

Claims (3)

A common electrode for excitation that is provided on one side of the crystal piece and is set to ground potential during oscillation;
The crystal pieces are provided on the other surface side of the crystal piece so as to be separated from each other and to face the common electrode, and each outer edge protrudes outward from a region facing the common electrode over the entire circumference of the common electrode. A first divided electrode and a second divided electrode formed as described above,
An adsorption layer formed on a surface of the common electrode and facing one of the first divided electrode and the second divided electrode, and adsorbs a sensing object in a sample solution;
A connection terminal portion for connecting each of the common electrode, the first divided electrode, and the second divided electrode to the oscillation circuit is provided, and a space is formed in a region facing the first divided electrode and the second divided electrode. A wiring board on which the crystal piece is fixed,
The common electrode is accommodated in a space serving as a sample liquid supply flow path formed above the common electrode by a flow path forming member, and an outer edge of each of the first divided electrode and the second divided electrode is A sensing sensor, which is located outside a region facing a space serving as a sample liquid supply channel . A flow path forming member for forming a space forming a supply flow path for the sample solution above the common electrode;
The flow path forming member is formed with a sample liquid inlet and a sample liquid outlet on one end side and the other end side, respectively.
When the other end side is viewed from one end side of the flow path forming member, the left edge side of the first divided electrode located on the left side and the right edge side of the second divided electrode located on the right side face the space. The sensor according to claim 1, wherein the sensor protrudes from the region.   The sensor according to claim 2, wherein the common electrode includes a region facing the first divided electrode and a region facing the second divided electrode, which are spaced apart from each other on the left and right.

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