JPWO2017068610A1 - Measuring apparatus and measuring method - Google Patents

Abstract

The sensor chip includes a first capacitor electrode, a first insulating film disposed on one surface of the first capacitor electrode, a second capacitor electrode and a variable resistance element disposed on the first insulating film, And a reaction element disposed on the other surface of the first capacitor electrode. The measuring apparatus includes a chip holder, a voltage applying unit for applying a voltage between the first capacitive electrode and the second capacitive electrode via a first mechanical contact switch and a second mechanical contact switch, A current measuring unit for measuring a current value flowing through the variable resistance element; and a pressing unit that switches the connection state by pressing the first mechanical contact switch and the second mechanical contact switch.

Description

  The present invention relates to a measuring apparatus and a measuring method for detecting the presence or amount of a substance to be detected in a specimen using a predetermined sensor chip.

  Conventionally, various sensor elements have been proposed as sensor elements for detecting a substance to be detected. For example, Patent Documents 1 and 2 disclose a sensor element including a back gate type field effect transistor.

  FIG. 1 is a schematic cross-sectional view illustrating a configuration of a sensor element described in Patent Documents 1 and 2. As shown in FIG. 1, the sensor element 10 includes a silicon substrate 11, a first insulating film 12 formed on one surface of the silicon substrate 11, and a second insulation formed on the other surface of the silicon substrate 11. A film 13, a channel 14 disposed on the first insulating film 12, a source electrode 15 connected to one end of the channel 14, a drain electrode 16 connected to the other end of the channel 14, The reaction portion 17 is disposed on the second insulating film 13, and the gate electrode 18 is disposed so as to face the second insulating film 13. In the reaction unit 17, a recognition substance 19 such as an antibody is immobilized on the second insulating film 13. The gate electrode 18 is detachable, and is removed when the specimen is provided to the reaction unit 17, and is disposed so as to face the second insulating film 13 when measuring. The gate electrode 18 is, for example, an aluminum plate.

  The sensor element described in Patent Document 1 has a channel 14 made of carbon nanotubes. The sensor element described in Patent Document 2 has a channel 14 made of a polysilicon film. In the sensor element 10, the silicon substrate 11, the first insulating film 12, the second insulating film 13, the channel 14, the source electrode 15, the drain electrode 16, and the gate electrode 18 function as a back gate type field effect transistor.

  A procedure for detecting a substance to be detected using the sensor element 10 shown in FIG. 1 will be described. First, the voltage applied to the gate electrode 18 is swept while the gate electrode 18 is in contact with the reaction portion 17 (second insulating film 13), and the current value between the source electrode 15 and the drain electrode 16 is recorded. Next, in a state where the gate electrode 18 is separated from the reaction part 17 (second insulating film 13), the specimen is provided to the reaction part 17, and the detection target substance contained in the specimen and the recognition immobilized on the second insulating film 13 are provided. The substance 19 is reacted. Next, the voltage applied to the gate electrode 18 is swept while the gate electrode 18 is again in contact with the reaction portion 17 (second insulating film 13), and the current value between the source electrode 15 and the drain electrode 16 is recorded. The substance to be detected can be detected from the change in the current value before and after the sample provision obtained by the above procedure.

International Publication No. 2006/103872 International Publication No. 2009/144878

  However, the conventional sensor element 10 has a problem that detection accuracy is unstable. In the conventional sensor element 10, it is necessary to remove the gate electrode 18 from the second insulating film 13 or dispose the gate electrode 18 on the second insulating film 13 a plurality of times. The contact state with the insulating film 13 changes every time. Further, when the gate electrode 18 made of an aluminum plate or the like is placed on the second insulating film 13, defects are easily formed in the second insulating film 13. For these reasons, in the conventional sensor element 10 described above, variations in the contact state of the gate electrode and charge injection into the silicon substrate due to breakdown of the insulating film are likely to occur, resulting in unstable detection accuracy.

  An object of the present invention is to provide a measuring apparatus and a measuring method for detecting the presence or amount of a substance to be detected using a sensor chip including a sensor element having excellent detection accuracy and stability.

The present invention relates to the following measuring apparatus.
[1] A first capacitor electrode made of a plate-like conductor or semiconductor, a first insulating film disposed on one surface of the first capacitor electrode, and the first capacitor electrode sandwiching the first insulating film On the other surface of the first capacitor electrode, a second capacitor electrode made of a conductor or semiconductor, a variable resistance element disposed on the first insulating film, A measuring device that detects the presence or amount of a substance to be detected using a sensor chip having one or more sensor elements including a reaction part arranged directly or via a second insulating film, A chip holder for holding a sensor chip, a push button type first mechanical contact switch connected to the first capacitance electrode of the sensor chip held by the chip holder, and held by the chip holder The above A push button type second mechanical contact switch connected to the second capacitor electrode of the circhip, and the first machine and the second capacitor electrode of the sensor chip held by the chip holder. A voltage application unit for applying a voltage between the first capacitor electrode and the second capacitor electrode, which is connected via a mechanical contact switch and the second mechanical contact switch, and is held by the chip holder A current measuring unit connected to the variable resistance element of the sensor chip for measuring a current value flowing through the variable resistance element; and pressing the first mechanical contact switch and the second mechanical contact switch. And a pressing unit that switches a connection state between the first capacitor electrode and the second capacitor electrode and the voltage application unit.
[2] The measuring device according to [1], wherein the first mechanical contact switch and the second mechanical contact switch are tactile switches.
[3] The sensor chip is connected to the measurement device side with a first contact terminal connected to the first capacitor electrode, a second contact terminal connected to the second capacitor electrode, and the variable resistance element. A third contact terminal and a fourth contact terminal, wherein the chip holder connects the first contact terminal and the voltage application unit via the first mechanical contact switch, and the second contact. A switch module for connecting the terminal and the voltage application unit via the second mechanical contact switch, and connecting the third contact terminal and the fourth contact terminal to the current measuring unit; The switch module includes a substrate, a first contact probe disposed on one surface of the substrate for contacting the first contact terminal, a second contact probe for contacting the second contact terminal, First A third contact probe for contacting the contact terminal, a fourth contact probe for contacting the fourth contact terminal, and the first contact probe and the second contact disposed on the other surface of the substrate A connector for connecting a probe and the voltage application unit, and a connector for connecting the third contact probe, the fourth contact probe, and the current measuring unit; and the first contact probe formed on the substrate; A first through-hole wiring that connects the connector; a second through-hole wiring that connects the second contact probe and the connector; a third through-hole wiring that connects the third contact probe and the connector; A fourth through hole connecting the fourth contact probe and the connector The first mechanical contact switch disposed on the other surface of the substrate and between the first through-hole wiring and the connector; and the second through-hole wiring and the connector. The measurement device according to [1] or [2], including the second mechanical contact switch disposed between the two.
[4] The switch module according to [3], further including a temperature sensor disposed on the other surface of the substrate and connected to the connector for detecting the temperature of the surrounding environment of the sensor chip. measuring device.
[5] The pressing portion increases the pressing force applied from the actuator that generates the pressing force by the lever principle and transmits it to the first mechanical contact switch and the second mechanical contact switch. The measuring device according to any one of [1] to [4], wherein the measuring device includes an increasing mechanism.
[6] The measuring apparatus according to [5], wherein the actuator is a solenoid actuator.
[7] The measuring device according to [5] or [6], wherein a contact surface of the increasing mechanism with respect to the first mechanical contact switch or the second mechanical contact switch constitutes a part of a cylindrical surface.
[8] The sensor chip is connected to the measurement device side with a first contact terminal connected to the first capacitor electrode, a second contact terminal connected to the second capacitor electrode, and the variable resistance element. A third contact terminal and a fourth contact terminal, wherein the chip holder connects the first contact terminal and the voltage application unit via the first mechanical contact switch, and the second contact. A switch module for connecting a terminal and the voltage application unit via the second mechanical contact switch, and connecting the third contact terminal and the fourth contact terminal to the current measuring unit, and one of them A first recess for fitting the sensor chip, and a second recess for inserting the switch module, which is disposed at a position corresponding to the first recess on the other surface. The first recess A holder body having a bottom portion and a through hole that opens at a bottom portion of the second recess, and the switch module contacts the first contact terminal disposed on one surface of the substrate. A first contact probe for contacting, a second contact probe for contacting the second contact terminal, a third contact probe for contacting the third contact terminal, and a second contact for contacting the fourth contact terminal A four-contact probe, and the first contact probe, the second contact probe, and the voltage application unit, which are disposed on the other surface of the substrate, and the third contact probe and the fourth contact probe; A connector for connecting the current measuring unit; the first contact probe formed on the substrate; and the connector. A first through-hole wiring that connects the second contact probe and the connector, a third through-hole wiring that connects the third contact probe and the connector, and the first through-hole wiring that connects the third contact probe and the connector; A fourth through-hole wiring connecting the four-contact probe and the connector; and the first mechanical contact disposed on the other surface of the substrate and disposed between the first through-hole wiring and the connector. A switch, and the second mechanical contact switch disposed between the second through-hole wiring and the connector, and the switch module includes the first contact probe, the second contact probe, The third contact probe and the fourth contact probe are exposed in the through hole. The pressing portion is fixed to the second recess by increasing the pressing force applied from the solenoid actuator and the solenoid actuator by the lever principle. An increase mechanism for transmitting to the first mechanical contact switch and the second mechanical contact switch of the switch module, and a fulcrum of the lever principle in the increase mechanism is supported by the holder body [1] or [2].

Moreover, this invention relates to the following measuring methods.
[9] A measurement method for detecting the presence or amount of a substance to be detected in a specimen using the measurement apparatus according to any one of [1] to [8], wherein the sensor chip is attached to the chip holder. And the pressing portion presses the first mechanical contact switch and the second mechanical contact switch to apply the voltage to the first capacitive electrode and the second capacitive electrode of the sensor chip. A second step of applying a voltage between the first capacitor electrode and the second capacitor electrode, and after the second step, the pressing portion is connected to the first mechanical contact switch and the second capacitor electrode. A third step of stopping the pressing of the second mechanical contact switch and separating the first capacitive electrode and the second capacitive electrode from the voltage application unit, and providing the specimen to the reaction unit after the third step And a fourth step, 4 after the step, including a fifth step of the current measuring unit measures the current flowing through the variable resistive element of the sensor chip, the measurement method.

  According to the measuring apparatus and the measuring method according to the present invention, since it is not necessary to repeatedly contact the electrode with the reaction part of the sensor chip, the presence or amount of the substance to be detected can be detected stably with high accuracy.

FIG. 1 is a cross-sectional view showing a configuration of a conventional sensor element. FIG. 2 is a schematic diagram illustrating a configuration of the measurement apparatus according to the embodiment. 3A is a plan view of the sensor chip, FIG. 3B is a front view of the sensor chip, and FIG. 3C is a bottom view of the sensor chip. 4A is a plan view of the sensor element, and FIG. 4B is a bottom view of the sensor element. 5A is a cross-sectional view taken along the line AA shown in FIG. 4B, and FIG. 5B is a cross-sectional view taken along the line BB shown in FIG. 4B. 6A to 6C are schematic cross-sectional views of the sensor element for explaining the operation principle of the sensor element. FIG. 7 is an exploded perspective view showing the configuration of the chip holder. FIG. 8A is an exploded sectional view showing the configuration of the chip holder, and FIG. 8B is a sectional view showing the configuration of the chip holder. 9A is a plan view of the switch module, FIG. 9B is a front view of the switch module, and FIG. 9C is a bottom view of the switch module. 10A is a graph showing a current value flowing through the variable resistance element when an analog switch is used, and FIG. 10B is a graph showing a current value flowing through the variable resistance element when a relay switch is used. These are the graphs which show the electric current value which flows through the variable resistance element at the time of using a tactile switch. FIG. 11 is a divided perspective view showing the configuration of the pressing portion. FIG. 12 is a perspective view showing the configuration of the pressing portion. FIG. 13 is a side view showing the configuration of the pressing portion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a schematic diagram showing the configuration of the measuring apparatus 100 according to an embodiment of the present invention. As shown in FIG. 2, the measuring apparatus 100 includes a chip holder 110, a pressing unit 140, a voltage applying unit 170, a current measuring unit 180, and a control unit 190. The chip holder 110 has a holder part 120 and a switch module 130. The pressing unit 140 includes an actuator 150 and an increase mechanism 160. The measuring apparatus 100 is used with the sensor chip 200 mounted on the chip holder 110. Therefore, the sensor chip 200 will be described first, and then the measurement apparatus 100 will be described.

[Sensor chip]
3A to 3C are diagrams showing a configuration of a sensor chip 200 according to an embodiment of the present invention. 3A is a plan view of the sensor chip 200, FIG. 3B is a front view of the sensor chip 200, and FIG. 3C is a bottom view of the sensor chip 200. FIG. 3A-C, the sensor chip 200 includes two sensor elements 210, a sensor chip substrate 220, two first contact terminals 230, two second contact terminals 240, two third contact terminals 250, and Two fourth contact terminals 260 are provided. The top surface of the sensor element 210 functions as a reaction unit 218 (reaction field) for detecting a substance to be detected.

(Sensor element)
4A and 4B and FIGS. 5A and 5B are diagrams showing the configuration of the sensor element 210. FIG. 4A is a plan view of the sensor element 210, and FIG. 4B is a bottom view of the sensor element 210. 5A is a cross-sectional view taken along the line AA shown in FIG. 4B, and FIG. 5B is a cross-sectional view taken along the line BB shown in FIG. 4B. 4A and 4B and FIGS. 5A and 5B, the sensor element 210 includes a first capacitor electrode 211, a first terminal 212, a first insulating film 213, a second insulating film 214, a second capacitor electrode 215, A two-terminal 216, a variable resistance element 217, and a reaction unit 218 are included.

  The first capacitor electrode 211 is a plate-like conductor or semiconductor. The first capacitor electrode 211 also functions as a substrate for the sensor element 210. For example, the first capacitor electrode 211 is a silicon substrate doped with impurities. Other examples of the material of the first capacitor electrode 211 include germanium, gallium arsenide (GaAs), indium phosphide (InP), zinc telluride (ZnTe), aluminum, magnesium, and the like. The thickness of the first capacitance electrode 211 is not particularly limited, and is about 0.5 mm, for example.

  The first terminal 212 is disposed on the back side (the sensor chip substrate 220 side) of the first capacitance electrode 211 and is electrically connected to the first capacitance electrode 211 (see FIG. 5A). The first terminal 212 electrically connects the first capacitor electrode 211 and a first through-hole wiring 221 (described later) of the sensor chip substrate 220. The first terminal 212 is a film made of, for example, polysilicon, metal, or alloy.

  The first insulating film 213 is an insulating film disposed on the back surface of the first capacitor electrode 211, and the second insulating film 214 is an insulating film disposed on the front surface of the first capacitor electrode 211. The first insulating film 213 insulates between the first capacitor electrode 211 and the second capacitor electrode 215 and between the first capacitor electrode 211 and the variable resistance element 217. The second insulating film 214 insulates between the first capacitor electrode 211 and the reaction part 218. Each of the first insulating film 213 and the second insulating film 214 may be a single layer or may be composed of two or more layers. The first insulating film 213 and the second insulating film 214 are, for example, silicon oxide films. Other examples of the material of the first insulating film 213 and the second insulating film 214 include silicon nitride, aluminum oxide, titanium oxide, acrylic resin, polyimide, and the like. The film thicknesses of the first insulating film 213 and the second insulating film 214 are not particularly limited.

  The second capacitor electrode 215 is a member made of a conductor or a semiconductor disposed on the first insulating film 213. The second capacitor electrode 215 faces the first capacitor electrode 211 with the first insulating film 213 interposed therebetween. The first capacitor electrode 211, the first insulating film 213, and the second capacitor electrode 215 constitute a capacitor. The second capacitor electrode 215 is a film made of, for example, polysilicon, metal, or alloy. Examples of the metal and alloy constituting the second capacitor electrode 215 include aluminum, aluminum alloy, copper, copper alloy and the like. When the first capacitor electrode 211 is a silicon substrate doped with impurities and the second capacitor electrode 215 is a polysilicon film doped with impurities, the polarity of the impurities doped in the first capacitor electrode 211 and the first The polarities of the impurities doped in the two-capacitance electrode 215 may be the same, but are preferably different from each other.

  The second terminal 216 is disposed on the second capacitor electrode 215 and is electrically connected to the second capacitor electrode 215 (see FIG. 5A). The second terminal 216 electrically connects the second capacitor electrode 215 and the second through-hole wiring 222 (described later) of the sensor chip substrate 220. The second terminal 216 is a film made of, for example, polysilicon, metal, or alloy.

  The variable resistance element 217 is disposed on the first insulating film 213 and functions as a transducer. The variable resistance element 217 is electrically connected to the base 217a disposed on the first insulating film 213, the third terminal 217b electrically connected to one end of the base 217a, and the other end of the base 217a. And a fourth terminal 217c connected to the. The third terminal 217b electrically connects one end of the base 217a and a third through-hole wiring 223 (described later) of the sensor chip substrate 220. The fourth terminal 217c electrically connects the other end of the base 217a and a fourth through-hole wiring 224 (described later) of the sensor chip substrate 220. As will be described later, when a substance to be detected is detected, a current flowing between the third terminal 217b and the fourth terminal 217c is measured with a voltage applied between the third terminal 217b and the fourth terminal 217c. To do. The variable resistance element 217 (base 217 a) has a resistance value due to the influence of isolated charges accumulated in the first capacitor electrode 211 and charges in the first capacitor electrode 211 induced by charges generated in the reaction unit 218. Change.

  The base 217a is, for example, a carbon nanotube or a polysilicon film. In the case where the substrate 217a is a polysilicon film, the substrate 217a may be a polysilicon film doped with low-concentration impurities or a non-doped polysilicon film. The third terminal 217b and the fourth terminal 217c are, for example, aluminum films. Further, when the base 217a is a polysilicon film, the third terminal 217b and the fourth terminal 217c may be a polysilicon film doped with impurities. When the base 217a is a polysilicon film doped with low-concentration impurities, and the third terminal 217b and the fourth terminal 217c are polysilicon films doped with impurities, the polarity of the impurities doped into the base 217a, The polarities of the impurities doped in the third terminal 217b and the fourth terminal 217c are preferably the same. When the base 217a is a polysilicon film, the third terminal 217b and the fourth terminal 217c are polysilicon films doped with impurities, and the first capacitor electrode 211 is a silicon substrate doped with impurities, The polarity of the impurity doped in the first capacitor electrode 211 and the polarity of the impurity doped in the third terminal 217b and the fourth terminal 217c may be the same, but are preferably different from each other.

  The shape and size of the base 217a are not particularly limited. From the viewpoint of utilizing the shielding effect from the outside, the base 217a is preferably surrounded by the second capacitor electrode 215 (see FIG. 4B). Therefore, the size of the base 217a is preferably a size that can be surrounded by the second capacitor electrode 215.

  The reaction unit 218 is disposed on the second insulating film 214 and is provided with a specimen that can contain a substance to be detected. In the reaction unit 218, a recognition substance 219 that can react with the substance to be detected is immobilized on the second insulating film 214 in advance (not shown in FIG. 4A). The type of the recognition substance 219 is not particularly limited as long as it can react with the substance to be detected, and may be an organic substance or an inorganic substance. Examples of the recognition substance 219 include antibodies, antigens, enzymes, lectins, nucleic acids and the like. When the specimen is provided to the reaction unit 218, the target substance contained in the specimen and the recognition substance 219 immobilized on the second insulating film 214 react.

  Here, the sensor element 210 in which the second insulating film 214 exists between the first capacitor electrode 211 and the reaction portion 218 is described, but the second insulating film 214 may be omitted. That is, the reaction unit 218 may be directly disposed on the front surface of the first capacitance electrode 211. In this case, the recognition substance 219 is immobilized on the surface on the front side of the first capacitance electrode 211.

  In the present embodiment, two sensor elements 210 are arranged on one sensor chip substrate 220. That is, the sensor chip 200 has two sensor elements 210. In this case, one sensor element 210 can be used for detection and the other sensor element 210 can be used for reference. Since the measuring apparatus 100 can eliminate the influence of the external environment by using the difference value between the outputs of the two sensor elements 210 and 210, it can detect the substance to be detected with higher accuracy and higher sensitivity.

  The method for manufacturing the sensor element 210 is not particularly limited. The sensor element 210 can be manufactured by a general semiconductor element manufacturing process.

(Sensor chip substrate)
The sensor chip substrate 220 is an insulating plate. In the present embodiment, two sensor elements 210 are arranged on the front surface of the sensor chip substrate 220. Two first contact terminals 230, two second contact terminals 240, two third contact terminals 250, and two fourth contact terminals 260 are arranged on the back side (measurement apparatus 100 side) surface of the sensor chip substrate 220. Is done. The sensor chip substrate 220 is, for example, a glass composite substrate or a glass epoxy substrate.

  The sensor chip substrate 220 includes two first through-hole wirings 221, two second through-hole wirings 222, two third through-hole wirings 223, and two fourth through-hole wirings 224. The first through-hole wiring 221 is disposed immediately below the first terminal 212 of the sensor element 210 and electrically connects the first terminal 212 and the first contact terminal 230. The second through-hole wiring 222 is disposed immediately below the second terminal 216 of the sensor element 210 and electrically connects the second terminal 216 and the second contact terminal 240. The third through-hole wiring 223 is disposed immediately below the third terminal 217b of the sensor element 210, and electrically connects the third terminal 217b and the third contact terminal 250. The fourth through-hole wiring 224 is disposed immediately below the fourth terminal 217c of the sensor element 210, and electrically connects the fourth terminal 217c and the fourth contact terminal 260.

  On the front side of the sensor chip substrate 220, the first through-hole wiring 221, the second through-hole wiring 222, the third through-hole wiring 223, and the fourth through-hole wiring 224 are respectively connected to the first through-hole wiring 224 of the sensor element 210 without going through the printed wiring. The first terminal 212, the second terminal 216, the third terminal 217b, and the fourth terminal 217c are connected. For the connection with each terminal, a conductive fixing material such as solder or silver paste can be used. On the other hand, on the back side of the sensor chip substrate 220, the first through-hole wiring 221, the second through-hole wiring 222, the third through-hole wiring 223, and the fourth through-hole wiring 224 are respectively connected to the first contact terminal via the printed wiring. 230, the second contact terminal 240, the third contact terminal 250, and the fourth contact terminal 260. Therefore, in the sensor chip 200, the printed wiring is concentrated on the back side of the sensor chip substrate 220. In order to more securely fix the sensor element 210 to the sensor chip substrate 220, an insulating adhesive may be injected between the sensor element 210 and the sensor chip substrate 220 and cured.

(Contact terminal)
The first contact terminal 230, the second contact terminal 240, the third contact terminal 250, and the fourth contact terminal 260 are arranged on the back side (measurement device 100 side) surface of the sensor chip substrate 220. These are films made of, for example, a metal or an alloy, and function as contact terminals with the measuring apparatus 100. The first contact terminal 230 is electrically connected to the first terminal 212 of the sensor element 210 via the first through-hole wiring 221. The second contact terminal 240 is electrically connected to the second terminal 216 of the sensor element 210 via the second through-hole wiring 222. The third contact terminal 250 is electrically connected to the third terminal 217 b of the sensor element 210 via the third through-hole wiring 223. The fourth contact terminal 260 is electrically connected to the fourth terminal 217 c of the sensor element 210 via the fourth through-hole wiring 224.

(How to use the sensor element)
Next, an example of a detection procedure for a substance to be detected using the sensor element 210 included in the sensor chip 200 and an inferred detection mechanism will be described. 6A to 6C are schematic cross-sectional views of the sensor element 210 for explaining the operation principle of the sensor element 210. FIG. In order to facilitate understanding, the positions and shapes of the components are changed in these drawings. Further, the recognition substance 219 is omitted. The third terminal 217b and the fourth terminal 217c of the variable resistance element 217 are connected in advance to an ammeter (the current measuring unit 180 of the measuring apparatus 100).

  First, the first terminal 212 and the second terminal 216 are connected to a power source (the voltage application unit 170 of the measuring apparatus 100) (indicated by a black circle in the figure), and a predetermined amount is provided between the first capacitor electrode 211 and the second capacitor electrode 215. Apply a voltage of. At this time, it is preferable to apply a voltage so that a depletion layer is not formed in a portion of the first capacitor electrode 211 on the first insulating film 213 side and a portion of the second capacitor electrode 215 on the first insulating film 213 side. As described above, the first capacitor electrode 211, the first insulating film 213, and the second capacitor electrode 215 constitute a capacitor. Therefore, as shown in FIG. 6A, electric charges that can be uniquely controlled by the applied voltage and the capacitance value of the capacitance can be accumulated in the first capacitor electrode 211 and the second capacitor electrode 215.

  Thereafter, the first terminal 212 and the second terminal 216 are disconnected from the power source (indicated by white circles in the figure), and the first capacitor electrode 211 and the second capacitor electrode 215 are set in an isolated state (not shown). As a result, the accumulated charges in the first capacitor electrode 211 and the second capacitor electrode 215 become isolated charges. This isolated charge greatly affects the detection sensitivity of the sensor element 210. Therefore, the voltage applied between the first capacitor electrode 211 and the second capacitor electrode 215 is appropriately set according to the required detection sensitivity.

  In this state, once a predetermined voltage is applied between the third terminal 217b and the fourth terminal 217c (indicated by a black circle in the figure), the current value between the third terminal 217b and the fourth terminal 217c is set. Measure (not shown).

  Next, the specimen is provided to the reaction unit 218, and the substance to be detected included in the specimen is reacted with the recognition substance 219 immobilized on the second insulating film 214. As shown in FIG. 6B, electric charges are generated on the second insulating film 214 by this reaction. Furthermore, as shown in FIG. 6C, a new charge that is polarized is induced in the first capacitor electrode 211 by the electric field generated by the charge generated on the second insulating film 214. In the absence of the second insulating film 214, the electric field generated by the charge generated by the reaction between the recognition substance 219 directly immobilized on the front surface of the first capacitance electrode 211 and the target substance contained in the specimen, A charge that is polarized in the first capacitor electrode 211 is newly induced.

  In this state, a predetermined voltage (the same voltage as the first measurement) is applied again between the third terminal 217b and the fourth terminal 217c of the variable resistance element 217, and the third terminal 217b and the fourth terminal 217c are applied. Measure the current value between. The second measurement after the sample is provided may be performed before the sample is dried or may be performed after the sample is dried. In the first measurement before the sample is provided, the resistance value of the variable resistance element 217 is determined by the electric field formed by the isolated charges accumulated in the first capacitor electrode 211. On the other hand, in the second measurement after the sample is provided, the resistance value of the variable resistance element 217 is the first polarization induced by the isolated charge accumulated in the first capacitance electrode 211 and the charge generated in the reaction unit 218. It is determined by the electric field formed by the charge in the capacitor electrode 211. Therefore, it is possible to detect the presence or absence or amount of the substance to be detected from the change in the current value before and after the sample is provided.

  When the relationship between the electric field and the resistance value of the variable resistance element 217 is observed, the range in which the resistance value changes sharply is usually limited. For this reason, it is necessary to adjust the amount of isolated charges in the first capacitor electrode 211 so that the resistance value of the variable resistance element 217 changes sharply due to a change in the electric field caused by the reaction in the reaction unit 218. .

  With the above procedure, the presence or amount of the substance to be detected can be detected using the sensor element 210.

  Note that, from the viewpoint of improving detection accuracy, the residual charges of the first capacitor electrode 211 and the second capacitor electrode 215 are removed immediately before a voltage is applied between the first capacitor electrode 211 and the second capacitor electrode 215. Is preferred. In this way, the amount of isolated charges in the first capacitor electrode 211 can be controlled with higher accuracy.

  In the sensor chip 200 according to the present embodiment, each contact terminal (the first contact terminal 230, the second contact terminal 240, the third contact terminal 250, and the fourth contact terminal 260) for connection with the measuring apparatus 100 is used as a sensor. It is arranged in the vicinity immediately below the element 210. Further, contact terminals (first contact terminal 230, second contact terminal) for connecting each terminal (first terminal 212, second terminal 216, third terminal 217 b and fourth terminal 217 c) of the sensor element 210 and the measuring apparatus 100. The contact terminal 240, the third contact terminal 250, and the fourth contact terminal 260 are connected to the through-hole wiring (first through-hole wiring 221, second through-hole wiring 222, third through-hole wiring 223, and fourth through-hole wiring 224). ) Through the shortest distance. In addition, no wiring is arranged on the front side (sensor element 210 side) of the sensor chip substrate 220, and the wiring is arranged only on the back side (measurement device 100 side) of the sensor chip substrate 220. With these features, the stray capacitance in the sensor chip 200 can be reduced. It is considered that the sensitivity of measurement using the sensor element 210 can be improved by reducing the stray capacitance in the sensor chip 200.

[measuring device]
Next, the measuring apparatus 100 will be described. As described above, the measuring apparatus 100 includes the chip holder 110, the pressing unit 140, the voltage applying unit 170, the current measuring unit 180, and the control unit 190 (see FIG. 2).

(Chip holder)
The chip holder 110 holds the sensor chip 200.

  FIG. 7 is an exploded perspective view showing the configuration of the chip holder 110. FIG. 8A is an exploded cross-sectional view showing the configuration of the chip holder 110. FIG. 8B is a cross-sectional view showing the configuration of the chip holder 110. In these drawings, the sensor chip 200 is also illustrated for facilitating understanding. As shown in FIG. 7, FIG. 8A and FIG. 8B, the chip holder 110 has a holder part 120 and a switch module 130. The holder part 120 is divided into a holder main body 121 and a lid part 127. In FIG. 2, the holder portion 120 (the holder main body 121 and the lid portion 127) is illustrated as an integral unit. In FIG. 7, the lid 127 is omitted.

  The holder main body 121 holds the sensor chip 200 together with the lid portion 127. Further, a switch module 130 (described later) is fixed to the holder main body 121, and the holder main body 121 brings each contact terminal of the sensor chip 200 into contact with each contact probe of the switch module 130. As shown in FIGS. 7, 8A and 8B, the holder main body 121 includes a first concave portion 122 disposed on the front surface and a second concave portion disposed at a position corresponding to the first concave portion 122 on the rear surface. It has a recess 123, a first through hole 124 that opens to the bottom of the first recess 122 and the bottom of the second recess 123, and six first magnets 125. The first recess 122 is substantially the same shape as the outer shape of the sensor chip 200 and is a recess for fitting the sensor chip 200 therein. The second recess 123 has substantially the same shape as the outer shape of the switch module 130 and is a recess for fitting the switch module 130 therein. The back surface (surface on which each contact terminal is disposed) of the sensor chip 200 and the front surface (surface on which each contact probe is disposed) of the switch module 130 are opposed to each other through the first through hole 124. (See FIG. 8B). The depth of the first through-hole 124 (the distance between the bottom surface of the first recess 122 and the bottom surface of the second recess 123) is the contact probe of the switch module 130 when the sensor chip 200 is fitted into the first recess 122. The resistance value (described later) is appropriately set so as to be within a desired range. The first magnet 125 attracts the second magnet 129 of the lid 127 to fix the lid 127 at a predetermined position. The material of the holder main body 121 (excluding the first magnet 125) is not particularly limited, but a resin is preferable from the viewpoint of reducing stray capacitance with the sensor element 210. The number of the first magnets 125 is not particularly limited as long as the lid 127 can be fixed, and can be arbitrarily selected.

  The lid portion 127 is disposed on the holder main body 121 and presses the outer peripheral portion of the sensor chip 200 fitted in the first concave portion 122 of the holder main body 121 from above. The lid 127 has a second through hole 128 and six second magnets 129. The sensor element 210 of the sensor chip 200 is exposed to the outside through the second through hole 128. Therefore, even if the sensor chip 200 is set in the holder part 120 (the holder main body 121 and the lid part 127), the user can provide the specimen to the reaction part 218 of the sensor element 210. The material of the lid 127 (excluding the second magnet 129) is not particularly limited, but a resin is preferable from the viewpoint of reducing stray capacitance with the sensor element 210. The number of second magnets 129 is normally the same as the number of first magnets 125, but is not particularly limited as long as lid portion 127 can be fixed.

  The switch module 130 is fixed to the second recess 123 of the holder main body 121, and each contact terminal (the first contact terminal 230, the second contact terminal 240, the third contact terminal 250, and the fourth contact terminal 260) of the sensor chip 200. ) And the voltage application unit 170 and the current measurement unit 180 of the measurement apparatus 100 are connected. More specifically, the switch module 130 connects the first contact terminal 230 of the sensor chip 200 and the voltage application unit 170 via the first mechanical contact switch 135, and the second contact terminal 240 of the sensor chip 200. The voltage application unit 170 is connected via the second mechanical contact switch 136. The switch module 130 connects the third contact terminal 250 and the fourth contact terminal 260 of the sensor chip 200 and the current measuring unit 180.

  9A to 9C are diagrams illustrating the configuration of the switch module 130. 9A is a plan view of the switch module 130, FIG. 9B is a front view of the switch module 130, and FIG. 9C is a bottom view of the switch module 130. 9A to 9C, the switch module 130 includes a switch module substrate 131, two first contact probes 133a, two second contact probes 133b, two third contact probes 133c, and two fourth contact probes. 133d, two connectors 134, two first mechanical contact switches 135, two second mechanical contact switches 136, and two temperature sensors 137.

  The switch module substrate 131 is an insulating plate. Two first contact probes 133a, two second contact probes 133b, two third contact probes 133c, and two fourth contact probes 133d are arranged on the surface of the switch module substrate 131 (sensor chip 200 side). Is done. The switch module substrate 131 is, for example, a glass composite substrate or a glass epoxy substrate.

  The switch module substrate 131 has two fifth through-hole wirings 132a, two sixth through-hole wirings 132b, two seventh through-hole wirings 132c, and two eighth through-hole wirings 132d. The fifth through-hole wiring 132a is disposed immediately below the first contact probe 133a and electrically connects the first contact probe 133a and the first mechanical contact switch 135. The sixth through-hole wiring 132b is disposed immediately below the second contact probe 133b and electrically connects the second contact probe 133b and the second mechanical contact switch 136. The seventh through-hole wiring 132c is disposed immediately below the third contact probe 133c, and electrically connects the third contact probe 133c and the connector 134. The eighth through-hole wiring 132d is disposed immediately below the fourth contact probe 133d, and electrically connects the fourth contact probe 133d and the connector 134.

  On the front side of the switch module substrate 131, the fifth through-hole wiring 132a, the sixth through-hole wiring 132b, the seventh through-hole wiring 132c, and the eighth through-hole wiring 132d are respectively connected to the first contact probe 133a without going through the printed wiring. The second contact probe 133b, the third contact probe 133c, and the fourth contact probe 133d are connected. For connection with each contact probe, a conductive fixing material such as solder or silver paste can be used. On the other hand, on the back side of the switch module substrate 131, the seventh through-hole wiring 132c and the eighth through-hole wiring 132d are each connected to the connector 134 via printed wiring. The first mechanical contact switch 135, the second mechanical contact switch 136, and the temperature sensor 137 are also connected to the connector 134 through printed wiring. Therefore, in the switch module 130, the printed wiring is concentrated on the back side of the switch module substrate 131. Thereby, reduction of the stray capacitance in the switch module 130 is realized. It is considered that the sensitivity of measurement using the sensor element 210 can be improved by reducing the stray capacitance in the switch module 130.

  The first contact probe 133a, the second contact probe 133b, the third contact probe 133c, and the fourth contact probe 133d are disposed on the front side (sensor chip 200 side) surface of the switch module substrate 131. These are spring pins, for example, and function as contact terminals with the sensor chip 200. When the sensor chip 200 is fitted into the first recess 122, the first contact probe 133 a contacts the first contact terminal 230 of the sensor chip 200. Similarly, the second contact probe 133b contacts the second contact terminal 240 of the sensor chip 200. The third contact probe 133c contacts the third contact terminal 250 of the sensor chip 200. The fourth contact probe 133d contacts the fourth contact terminal 260 of the sensor chip 200.

  The connector 134 is disposed on the back surface of the switch module substrate 131 and connects each element or each terminal of the switch module 130 to the voltage application unit 170, the current measurement unit 180, or the control unit 190. More specifically, the connector 134 connects the first contact probe 133a and the second contact probe 133b and the voltage application unit 170, and connects the third contact probe 133c and the fourth contact probe 133d and the current measurement unit 180. Then, the temperature sensor 137 and the control unit 190 are connected. As will be described later, a first mechanical contact switch 135 is disposed between the first contact probe 133a and the connector 134, and a second mechanical contact switch is disposed between the second contact probe 133b and the connector 134. 136 is arranged.

  The first mechanical contact switch 135 is disposed between the first contact probe 133 a and the connector 134 and switches the connection state between the first capacitance electrode 211 and the voltage application unit 170. Similarly, the second mechanical contact switch 136 is disposed between the second contact probe 133b and the connector 134, and switches the connection state between the second capacitor electrode 215 and the voltage application unit 170. The first mechanical contact switch 135 and the second mechanical contact switch 136 connect the first capacitor electrode 211 and the second capacitor electrode 215 and the voltage application unit 170 when pressed by a pressing unit 140 (described later). As a result, charges are accumulated in the first capacitor electrode 211 and the second capacitor electrode 215 of the sensor element 210. When the pressing by the pressing unit 140 is released, the first mechanical contact switch 135 and the second mechanical contact switch 136 block the first capacitor electrode 211 and the second capacitor electrode 215 and the voltage application unit 170. As a result, the accumulated charges in the first capacitor electrode 211 and the second capacitor electrode 215 become isolated charges. As described above, since this isolated charge greatly affects the detection sensitivity of the sensor element 210, it is preferable that the change in accumulated charge with time is as small as possible. Therefore, from the viewpoint of maintaining detection sensitivity, the first mechanical contact switch 135 and the second mechanical contact switch 136 are required to have a small stray capacitance and zero off-current.

  From the above viewpoint, in the measuring apparatus 100 according to the present embodiment, push button type mechanical contact switches are used as the first mechanical contact switch 135 and the second mechanical contact switch 136. Examples of push button type mechanical contact switches include a tactile switch and a detection (detection) switch. In general measuring apparatuses, analog switches and relay switches that can be controlled by electric signals are often used. However, the analog switch is not preferable as a switch used in combination with the sensor element 210 because the off-state current is not 0 and causes the accumulated charge to change (see FIG. 10A). The relay switch is not preferable as a switch to be used in combination with the sensor element 210 because a back electromotive voltage of the coil is generated at the time of switching on / off, and accumulated charges that may affect the detection sensitivity are generated in the switch ( (See FIG. 10B). On the other hand, the mechanical contact switch is preferable as a switch used in combination with the sensor element 210 because the off-current is 0 and no accumulated charge is generated in the switch (see FIG. 10C). In particular, the tactile switch is suitable for the first mechanical contact switch 135 and the second mechanical contact switch 136 because the tactile switch has a low profile and can be miniaturized, has a small switch stroke, and requires a small pressing force. It is.

  FIG. 10A shows the current flowing through the variable resistance element 217 when two analog switches are used instead of the first mechanical contact switch 135 and the second mechanical contact switch 136 in the measuring apparatus 100 according to the present embodiment. It is a graph which shows a time-dependent change. In this experiment, a voltage of −3 V was applied between the first capacitor electrode 211 and the second capacitor electrode 215 for 30 seconds with the two analog switches turned on, and then the variable resistor with the two analog switches turned off. The current flowing through the element 217 was measured (solid line). In addition to turning off the two analog switches, the current flowing through the variable resistance element 217 is measured even when the wiring between the first capacitor electrode 211 and the second capacitor electrode 215 and the two analog switches is removed. (Dashed line). From the result of the solid line, it can be seen that when an analog switch is used, the current flowing through the variable resistance element 217 changes over time. The slope of the graph changes according to the voltage between the two analog switches, and if the wiring between the first capacitor electrode 211 and the second capacitor electrode 215 and the two analog switches is removed, the change in current with time is eliminated. Therefore, it is considered that this change in current with time is due to the fact that the off-state current of the analog switch is not zero.

  FIG. 10B shows the current flowing through the variable resistance element 217 when two relay switches are used instead of the first mechanical contact switch 135 and the second mechanical contact switch 136 in the measuring apparatus 100 according to the present embodiment. It is a graph which shows a time-dependent change. In this experiment, a voltage of −3 V was applied between the first capacitor electrode 211 and the second capacitor electrode 215 for 30 seconds with the two relay switches turned on, and then the variable resistor with the two relay switches turned off. The current flowing through the element 217 was measured. From the graph, it can be seen that when a relay switch is used, the current flowing through the variable resistance element 217 changes (increases) greatly immediately after the start of measurement. This temporary change in current is considered to be caused by the accumulated electric charge generated in the switch due to the occurrence of a counter electromotive voltage in the coil at the on / off switching.

  FIG. 10C shows the time lapse of the current flowing through the variable resistance element 217 when two tactile switches are used as the first mechanical contact switch 135 and the second mechanical contact switch 136 in the measuring apparatus 100 according to the present embodiment. It is a graph which shows a change. In this experiment, a voltage of −3 V was applied between the first capacitive electrode 211 and the second capacitive electrode 215 for 30 seconds with the two tactile switches turned on, and then the variable resistance with the two tactile switches turned off. The current flowing through the element 217 was measured. From the graph, it can be seen that when the tactile switch is used, the current flowing through the variable resistance element 217 is stable for at least 30 minutes, unlike when the analog switch or the relay switch is used.

  The temperature sensor 137 is disposed on the back surface of the switch module substrate 131 and detects the temperature of the surrounding environment of the sensor chip 200. The detection value is output to the control unit 190 via the connector 134. Since the detection sensitivity of the sensor element 210 is temperature-dependent, the control unit 190 preferably corrects the detection value using the output value from the temperature sensor 137. The number of temperature sensors 137 is not particularly limited, but the temperature of the surrounding environment of the sensor chip 200 can be detected with high accuracy by using two temperature sensors 137 as in the present embodiment.

(Pressing part)
The pressing unit 140 presses the first mechanical contact switch 135 and the second mechanical contact switch 136 to switch the connection state between the first capacitor electrode 211 and the second capacitor electrode 215 and the voltage application unit 170. As shown in FIG. 2, in the present embodiment, the measuring apparatus 100 includes two pressing portions 140, and each pressing portion 140 includes one first mechanical contact switch 135 and one second mechanical contact. The switches 136 are pressed simultaneously.

  FIG. 11 is an exploded perspective view showing the configuration of the pressing unit 140. FIG. 12 is a perspective view illustrating a configuration of the pressing unit 140. FIG. 13 is a side view illustrating the configuration of the pressing unit 140. In FIG. 13, the sensor chip 200 and the chip holder 110 (the holder main body 121, the lid 127, and the switch module 130) are also illustrated together with the pressing unit 140 for facilitating understanding. As shown in FIGS. 11 to 13, the pressing unit 140 includes an actuator 150 and an increase mechanism 160.

  The actuator 150 is a power source that generates a pressing force for pressing the first mechanical contact switch 135 and the second mechanical contact switch 136. The type of the actuator 150 is such that the first mechanical contact switch 135 and the second mechanical contact switch 136 are pressed via the increasing mechanism 160, whereby the first capacitive electrode 211, the second capacitive electrode 215, the voltage applying unit 170, There is no particular limitation as long as the connection state can be switched. In the present embodiment, the actuator 150 is a small-sized pull-type solenoid actuator that can respond at high speed. In the measuring apparatus 100 according to the present embodiment, the pressing force of the actuator 150 is increased by the increasing mechanism 160. Therefore, even if a solenoid actuator is used as the actuator 150, the first mechanical contact switch 135 and the second mechanical contact switch 136 are not provided. Can be switched.

  The increasing mechanism 160 increases the pressing force applied from the actuator 150 according to the lever principle and transmits it to the first mechanical contact switch 135 and the second mechanical contact switch 136. The increase mechanism 160 includes a transmission unit 161 and an increase unit 166.

  The transmission unit 161 is fixed to the movable unit of the actuator 150, and transmits the pressing force applied from the actuator 150 to the input surface 167 provided at the power point of the increase unit 166. The transmission unit 161 includes a third recess 162 for fitting the movable portion of the actuator 150 and a pressing surface 163 that faces the input surface 167 of the increase unit 166.

  The increasing unit 166 increases the pressing force transmitted from the transmitting unit 161 based on the lever principle and transmits the pressing force to the first mechanical contact switch 135 and the second mechanical contact switch 136. The increasing portion 166 includes an input surface 167 that faces the pressing surface 163 of the transmission portion 161, a push rod 168 that faces the first mechanical contact switch 135 and the second mechanical contact switch 136, and the input surface 167 and push rod 168. And a shaft portion 169 disposed between the two. The input surface 167 functions as a power point, the push rod 168 functions as an action point, and the shaft portion 169 functions as a fulcrum. The push rod 168 has a cylindrical shape. That is, the contact surfaces of the increasing mechanism 161 with respect to the first mechanical contact switch 135 and the second mechanical contact switch 136 constitute a part of a cylindrical surface. The shaft portion 169 serving as a fulcrum of the lever principle is supported by a fulcrum through-hole 126 provided in the holder main body 121 (see FIGS. 8B and 13). A micro bearing is attached to the base end portion of the shaft portion 169.

(Voltage application unit, current measurement unit and control unit)
The voltage application unit 170 is connected to the first mechanical contact switch 135 and the second mechanical contact switch 136 via the connector 134 of the switch module 130. When the first mechanical contact switch 135 and the second mechanical contact switch 136 are on, the voltage application unit 170 is connected to the first capacitance electrode 211 and the second capacitance electrode 215 of the sensor element 210 of the sensor chip 200. The voltage application unit 170 applies a voltage between the first capacitor electrode 211 and the second capacitor electrode 215 when the first mechanical contact switch 135 and the second mechanical contact switch 136 are on.

  The current measurement unit 180 is connected to the variable resistance element 217 (the third terminal 217b and the fourth terminal 217c) of the sensor element 210 of the sensor chip 200 via the connector 134 of the switch module 130. The current measuring unit 180 measures the value of current flowing through the variable resistance element 217.

  The control unit 190 is connected to the actuator 150, the voltage application unit 170, and the current measurement unit 180, and controls these operations. The control unit 190 is also connected to the temperature sensor 137 of the switch module 130 via the connector 134 of the switch module 130, and the measured value of the current measuring unit 180 is measured according to the temperature of the surrounding environment of the sensor chip 200. to correct. The control unit 190 is a computer that executes software, for example.

(How to use the measuring device)
Next, an example of a procedure for detecting a substance to be detected using the measuring apparatus 100 shown in FIG. 2 will be described.

  First, the sensor chip 200 is held on the chip holder 110. Specifically, after the sensor chip 200 is fitted into the first recess 122 of the holder main body 121, the lid portion 127 is disposed on the sensor chip 200. The sensor chip 200 is fixed by the first magnet 125 of the holder main body 121 and the second magnet 129 of the lid portion 127 attracting each other. Thereby, each contact terminal of the sensor chip 200 is connected to each contact probe of the switch module 130.

  Next, a predetermined voltage is applied between the first capacitor electrode 211 and the second capacitor electrode 215 simultaneously for the two sensor elements 210 of the sensor chip 200. Specifically, the control unit 190 operates the actuator 150 to press the first mechanical contact switch 135 and the second mechanical contact switch 136, and the first capacitance electrode 211 and the second capacitance electrode of the sensor chip 200. 215 and the voltage application unit 170 are connected. Then, the control unit 190 causes the voltage application unit 170 to apply a predetermined voltage between the first capacitor electrode 211 and the second capacitor electrode 215. Thereby, in each of the two sensor elements 210, electric charges that can be uniquely controlled by the applied voltage and the capacitance value of the capacitance can be accumulated in the first capacitor electrode 211 and the second capacitor electrode 215.

  Next, the first capacitor electrode 211 and the second capacitor electrode 215 are separated from the voltage application unit 170 simultaneously for the two sensor elements 210 of the sensor chip 200. Specifically, the control unit 190 operates the actuator 150 to release the pressure on the first mechanical contact switch 135 and the second mechanical contact switch 136, and the first capacitance electrode 211 and the first capacitive electrode 211 of the sensor chip 200 are released. The two-capacitance electrode 215 and the voltage application unit 170 are disconnected. Thereby, in each of the two sensor elements 210, the accumulated charges in the first capacitor electrode 211 and the second capacitor electrode 215 become isolated charges.

  In this state, in each of the two sensor elements 210, the same predetermined voltage is applied between the third terminal 217b and the fourth terminal 217c of the variable resistance element 217, and the current value flowing through the variable resistance element 217 is determined. taking measurement. Specifically, the control unit 190 causes the current measurement unit 180 to calculate a difference value between the current value in the variable resistance element 217 of the sensor element 210 for detection and the current value in the variable resistance element 217 of the sensor element 210 for reference. To measure. If the difference value is not 0, the current measurement unit 180 performs offset adjustment so that the difference value becomes 0.

  Next, a sample is provided to the reaction unit 218 in the sensor element 210 for detection, and the detection target substance contained in the sample and the recognition substance 219 immobilized on the reaction unit 218 are reacted. At this time, the specimen is not provided to the reaction unit 218 of the reference sensor element 210.

  In this state, in each of the two sensor elements 210, a predetermined voltage (the same voltage as the first measurement) is applied between the third terminal 217b and the fourth terminal 217c of the variable resistance element 217, The current value flowing through the variable resistance element 217 is measured. Specifically, the control unit 190 causes the current measurement unit 180 to measure the current value in the variable resistance element 217 of the detection sensor element 210 and the current value in the variable resistance element 217 of the reference sensor element 210. . In the first measurement before the sample is provided, the resistance value of the variable resistance element 217 is determined by the electric field formed by the isolated charges accumulated in the first capacitor electrode 211. On the other hand, in the second measurement after the sample is provided, the resistance value of the variable resistance element 217 is the first polarization induced by the isolated charge accumulated in the first capacitance electrode 211 and the charge generated in the reaction unit 218. It is determined by the electric field formed by the charge in the capacitor electrode 211. Since the difference between the current values of the two sensor elements 210 is adjusted to 0 before the sample is provided, the difference between the current values of the two sensor elements 210 after the sample is provided is the response of the sensor element 210 for detection. This value reflects only the effect of the charge generated by the unit 218. In addition, the difference between the current values of the two sensor elements 210 can be amplified using the current measuring unit 180 in order to improve sensitivity. Therefore, the presence or amount of the substance to be detected can be detected by measuring the difference value between the current values of the two sensor elements 210.

  In this way, by measuring the difference between the current values of the two sensor elements 210, the influence of the variable factors common to the two sensor elements 210 can be eliminated, and only the effect of the detected substance can be detected with high sensitivity. Can do. That is, using the sensor chip 200, the presence or amount of the substance to be detected can be detected with high sensitivity and high accuracy.

  As described above, since the sensor chip 200 including the sensor element 210 according to the present embodiment does not need to repeatedly contact the electrode with the reaction portion unlike the conventional sensor element (see Patent Documents 1 and 2), it is high. The presence or amount of the substance to be detected can be detected stably with high accuracy. In addition, the sensor chip 200 including the sensor element 210 according to the present embodiment can easily and stably improve the detection sensitivity by adjusting the amount of isolated charges in the first capacitor electrode 211.

  In addition, the measuring apparatus 100 according to the present embodiment includes the first capacitive electrode 211 of the sensor element 210 and the first mechanical contact switch 135 of the push button type and the second mechanical contact switch 136 of the push button type. Since the application of voltage to the second capacitor electrode 215 is controlled, the amount of isolated charges in the first capacitor electrode 211 can be stably maintained for a long time. Therefore, the measuring apparatus 100 according to the present embodiment can stably perform highly sensitive detection.

  The measurement apparatus and measurement method according to the present invention are suitable for, for example, detection of infectious diseases, confirmation of food safety, detection of environmental pollutants, and the like.

DESCRIPTION OF SYMBOLS 10 Sensor element 11 Silicon substrate 12 1st insulating film 13 2nd insulating film 14 Channel 15 Source electrode 16 Drain electrode 17 Reaction part 18 Gate electrode 19 Recognized substance 100 Measuring apparatus 110 Chip holder 120 Holder part 121 Holder main body 122 1st recessed part 123 Second recess 124 First through-hole 125 First magnet 126 Support point through-hole 127 Cover portion 128 Second through-hole 129 Second magnet 130 Switch module 131 Switch module substrate 132a Fifth through-hole wiring 132b Sixth through-hole wiring 132c First 7 through-hole wiring 132d eighth through-hole wiring 133a first contact probe 133b second contact probe 133c third contact probe 133d fourth contact probe 134 Connector 135 1st mechanical contact switch 136 2nd mechanical contact switch 137 Temperature sensor 140 Press part 150 Actuator 160 Increase mechanism 161 Transmission part 162 3rd recessed part 163 Press surface 166 Increase part 167 Input surface 168 Push rod 169 Shaft part 170 Voltage Application unit 180 Current measurement unit 190 Control unit 200 Sensor chip 210 Sensor element 211 First capacitor electrode 212 First terminal 213 First insulating film 214 Second insulating film 215 Second capacitor electrode 216 Second terminal 217 Variable resistance element 217a Base 217b 3rd terminal 217c 4th terminal 218 Reaction part 219 Recognition substance 220 Sensor chip substrate 221 1st through-hole wiring 222 2nd through-hole wiring 223 3rd through-hole wiring 224 4th through-hole wiring 2 0 The first contact terminal 240 second contact terminal 250 third contact terminal 260 fourth contact terminal

Claims (9)

A first capacitor electrode made of a plate-like conductor or semiconductor;
A first insulating film disposed on one surface of the first capacitor electrode;
A second capacitor electrode made of a conductor or a semiconductor, disposed so as to face a part of the first capacitor electrode with the first insulating film interposed therebetween;
A variable resistance element disposed on the first insulating film;
A reaction part disposed directly or via a second insulating film on the other surface of the first capacitor electrode;
A measuring device that detects the presence or amount of a substance to be detected using a sensor chip having one or more sensor elements including:
A chip holder for holding the sensor chip;
A push button type first mechanical contact switch connected to the first capacitance electrode of the sensor chip held by the chip holder;
A push button type second mechanical contact switch connected to the second capacitance electrode of the sensor chip held by the chip holder;
The first capacitive electrode connected to the first capacitive electrode and the second capacitive electrode of the sensor chip held by the chip holder via the first mechanical contact switch and the second mechanical contact switch And a voltage applying unit for applying a voltage between the second capacitor electrode,
A current measurement unit for measuring a current value flowing through the variable resistance element connected to the variable resistance element of the sensor chip held by the chip holder;
A pressing unit that presses the first mechanical contact switch and the second mechanical contact switch to switch a connection state between the first capacitive electrode and the second capacitive electrode and the voltage application unit;
A measuring device.   The measuring device according to claim 1, wherein the first mechanical contact switch and the second mechanical contact switch are tactile switches. The sensor chip has a first contact terminal connected to the first capacitor electrode, a second contact terminal connected to the second capacitor electrode, and a second contact terminal connected to the variable resistance element on the measurement device side. 3 contact terminals and a fourth contact terminal,
The chip holder connects the first contact terminal and the voltage application unit via the first mechanical contact switch, and connects the second contact terminal and the voltage application unit to the second mechanical contact switch. And a switch module for connecting the third contact terminal and the fourth contact terminal to the current measuring unit,
The switch module is
A substrate,
A first contact probe disposed on one surface of the substrate for contacting the first contact terminal, a second contact probe for contacting the second contact terminal, and a contact for the third contact terminal. A third contact probe, and a fourth contact probe for contacting the fourth contact terminal;
The first contact probe, the second contact probe, and the voltage application unit, which are disposed on the other surface of the substrate, are connected, and the third contact probe, the fourth contact probe, and the current measurement unit are connected A connector for connecting,
A first through-hole wiring that connects the first contact probe and the connector, a second through-hole wiring that connects the second contact probe and the connector, the third contact probe, and the A third through-hole wiring connecting the connector, and a fourth through-hole wiring connecting the fourth contact probe and the connector;
The first mechanical contact switch disposed on the other surface of the substrate and disposed between the first through-hole wiring and the connector, and disposed between the second through-hole wiring and the connector. Said second mechanical contact switch,
Having
The measuring apparatus according to claim 1 or 2.   The measurement apparatus according to claim 3, wherein the switch module further includes a temperature sensor disposed on the other surface of the substrate and connected to the connector for detecting the temperature of the surrounding environment of the sensor chip. The pressing portion is
An actuator that generates a pressing force;
An increasing mechanism for increasing the pressing force applied from the actuator by the lever principle and transmitting it to the first mechanical contact switch and the second mechanical contact switch;
Having
The measuring apparatus as described in any one of Claims 1-4.   The measuring device according to claim 5, wherein the actuator is a solenoid actuator.   The measuring device according to claim 5 or 6, wherein a contact surface of the increasing mechanism with respect to the first mechanical contact switch or the second mechanical contact switch constitutes a part of a cylindrical surface. The sensor chip has a first contact terminal connected to the first capacitor electrode, a second contact terminal connected to the second capacitor electrode, and a second contact terminal connected to the variable resistance element on the measurement device side. 3 contact terminals and a fourth contact terminal,
The tip holder is
Connecting the first contact terminal and the voltage application unit via the first mechanical contact switch, connecting the second contact terminal and the voltage application unit via the second mechanical contact switch; And a switch module for connecting the third contact terminal and the fourth contact terminal to the current measuring unit;
A first recess for fitting the sensor chip disposed on one surface thereof, and a second recess for inserting the switch module disposed at a position corresponding to the first recess on the other surface. A holder body having a recess, and a through-hole opening in the bottom of the first recess and the bottom of the second recess;
Have
The switch module is
A substrate,
A first contact probe disposed on one surface of the substrate for contacting the first contact terminal, a second contact probe for contacting the second contact terminal, and a contact for the third contact terminal. A third contact probe, and a fourth contact probe for contacting the fourth contact terminal;
The first contact probe, the second contact probe, and the voltage application unit, which are disposed on the other surface of the substrate, are connected, and the third contact probe, the fourth contact probe, and the current measurement unit are connected A connector for connecting,
A first through-hole wiring that connects the first contact probe and the connector, a second through-hole wiring that connects the second contact probe and the connector, the third contact probe, and the A third through-hole wiring connecting the connector, and a fourth through-hole wiring connecting the fourth contact probe and the connector;
The first mechanical contact switch disposed on the other surface of the substrate and disposed between the first through-hole wiring and the connector, and disposed between the second through-hole wiring and the connector. Said second mechanical contact switch,
Have
The switch module is fixed to the second recess so that the first contact probe, the second contact probe, the third contact probe, and the fourth contact probe are exposed in the through hole,
The pressing portion is
A solenoid actuator that generates a pressing force;
Increase in which the pressing force applied from the solenoid actuator is increased by the lever principle and transmitted to the first mechanical contact switch and the second mechanical contact switch of the switch module fixed to the second recess. Mechanism,
Have
The fulcrum of the lever principle in the increasing mechanism is supported by the holder body,
The measuring apparatus according to claim 1 or 2. A measurement method for detecting the presence or amount of a substance to be detected in a specimen using the measurement apparatus according to any one of claims 1 to 8,
A first step of holding the sensor chip on the chip holder;
The pressing portion presses the first mechanical contact switch and the second mechanical contact switch, connects the first capacitance electrode and the second capacitance electrode of the sensor chip, and the voltage application unit, and A second step of applying a voltage between the first capacitor electrode and the second capacitor electrode;
After the second step, the pressing unit stops pressing the first mechanical contact switch and the second mechanical contact switch, and the first capacitive electrode and the second capacitive electrode are removed from the voltage application unit. A third step of separating,
A fourth step of providing a specimen to the reaction part after the third step;
After the fourth step, a fifth step in which the current measuring unit measures a current value flowing through the variable resistance element of the sensor chip;
Including a measuring method.

Images