JP2009276209A - Concentration measuring system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concentration measuring system and method capable of detecting a detection target substance within a proper detecting concentration range even if the concentration of the detection target substance is unknown by a simple constitution to measure the concentration of the detection target substance. <P>SOLUTION: The concentration measuring system includes an enzyme sensor 10 having a supply layer L1 receiving the supply of a fluid sample containing the detection target substance, the detection layer L2 arranged adjacent to the supply layer L1, the permeable membrane 400 arranged so as to separate the supply layer L1 and the detection layer L2 and permitting at least the permeation of the detection target substance, the electrode 240 arranged to the detection layer L2 in opposed relation to the permeable membrane 400 or the like, a valve drive device 40 for adjusting the pressure applied to the permeable membrane 400, and a supply side flow rate adjusting valve 42. The concentration of the detection target substance is measured on the basis of the detection result data related to the detection results of the enzyme sensor 10 and the adjusted pressure applied to the permeable membrane 400. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a concentration measurement system and a concentration measurement method.

2. Description of the Related Art Conventionally, research and development of sensors such as biosensors that detect the concentration of a specific substance in a gas sample or a liquid sample have been actively performed (see, for example, Patent Documents 1 to 3).
By the way, in a sensor, since the density | concentration of the detection target substance in a gas sample or a liquid sample is often unknown, it is desired to have a wide detection density range.

Therefore, for example, in an enzyme electrode, a space for filling a sample is formed by arranging and forming an oxygen permeable membrane at a pre-set height in the measurement electrode group placement portion, and the sample is filled in the space. An enzyme electrode has been proposed which is designed to reduce the height between the air interface and the measurement electrode group so that a high-concentration specimen can be detected and to solve the reaction limitation due to the oxygen reaction rate limiting ( For example, see Patent Document 4).
In addition, for example, in an electrochemical sensor, an electrochemical sensor configured to detect a high-concentration specimen by increasing the number of semipermeable membranes covering the working electrode has been proposed (for example, a patent) Reference 5).
For example, in a chemical sensor provided in the order of at least a transducer, a functional membrane, and a restricted permeable membrane, detection can be performed by appropriately setting the uneven shape formed on the surface of the restricted permeable membrane facing the functional membrane. A chemical sensor capable of setting a concentration range has been proposed (see, for example, Patent Document 6).
Special table 2007-511744 gazette JP 2005-265672 A Japanese Patent Laid-Open No. 08-193969 Japanese Patent No. 2536780 (FIG. 7) Japanese Patent Laid-Open No. 08-193969 (FIGS. 25 and 26) Japanese Patent No. 3683150

However, in the inventions described in Patent Documents 4 and 5, the detection concentration range is expanded by reducing the height between the air interface of the specimen and the measurement electrode group or increasing the number of layers of the semipermeable membrane. However, the wider the detection density range, the lower the accuracy and the larger the detection error when partially viewing the wide detection density range.
Further, in the invention described in Patent Document 6, the uneven shape of the restricted permeation membrane is set according to the concentration of the target detection target substance, but the concentration of the target detection target substance is unknown. In this case, there is a problem that a plurality of restricted permeable membranes having different concavo-convex shapes must be prepared.

  An object of the present invention is to provide a simple configuration that can detect the detection target substance in an appropriate detection concentration range even if the concentration of the detection target substance is unknown, and can measure the concentration of the detection target substance. It is to provide a measurement system and a concentration measurement method.

In order to solve the above-mentioned problem, the invention described in claim 1
In the concentration measurement system,
A supply layer to which a fluid sample containing a detection target substance is supplied; a detection layer disposed adjacent to the supply layer; and the supply layer and the detection layer being spaced apart, and at least the detection target A sensor having a permeable membrane through which a substance passes, and an electrode disposed on the detection layer so as to face the permeable membrane;
Adjusting means for adjusting the pressure applied to the permeable membrane;
Measurement means for measuring the concentration of the detection target substance based on detection result data relating to a detection result by the sensor and pressure applied to the permeable membrane adjusted by the adjustment means;
It is characterized by providing.

The invention described in claim 2
The concentration measurement system according to claim 1,
The measuring means includes
Adjustment control means for adjusting the adjustment means so that the pressure applied to the permeable membrane has a predetermined magnitude;
Obtaining means for obtaining response data relating to the response output of the sensor;
Determination means for determining whether a value based on the response data acquired by the acquisition means exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane;
A determination unit that determines the response data as the detection result data when the determination unit determines that the value based on the response data exceeds the threshold;
The adjustment control unit causes the adjustment unit to adjust the pressure applied to the permeable membrane to be larger than the previous time when the determination unit determines that the value based on the response data does not exceed the threshold value. It is characterized by that.

The invention according to claim 3
The concentration measurement system according to claim 1 or 2,
The concentration measuring system is characterized in that the adjusting means adjusts a pressure applied to the permeable membrane by adjusting a flow rate of a fluid sample supplied to the supply layer.

The invention according to claim 4
In the concentration measurement system according to any one of claims 1 to 3,
The adjusting means adjusts the pressure applied to the permeable membrane by adjusting the pressure in the supply layer.

The invention described in claim 5
In the concentration measuring system according to any one of claims 1 to 4,
The sensor is
A deformation preventing member that is disposed on at least one surface of the permeable membrane and prevents deformation of the permeable membrane is provided.

The invention described in claim 6
In the concentration measurement system according to any one of claims 1 to 5,
The sensor is
A spacer is provided between the permeable membrane and the electrode, and supports the permeable membrane so that the permeable membrane does not deform.

The invention described in claim 7
A supply layer to which a fluid sample containing a detection target substance is supplied; a detection layer disposed adjacent to the supply layer; and the supply layer and the detection layer being spaced apart, and at least the detection target In the method for measuring a concentration of a substance to be detected using a sensor having a permeable membrane through which a substance permeates and an electrode disposed on the detection layer so as to face the permeable membrane,
An adjustment step for adjusting the pressure applied to the permeable membrane to a predetermined magnitude;
Then, an acquisition step of acquiring response data regarding the response output of the sensor;
Next, a determination step of determining whether a value based on the acquired response data exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane;
A determination step of determining the response data as detection result data related to a detection result by the sensor when it is determined in the determination step that a value based on the response data exceeds the threshold;
A calculation step of calculating the concentration of the detection target substance based on the determined detection result data and the pressure applied to the permeable membrane adjusted by the adjustment unit;
When it is determined in the determination step that the value based on the response data does not exceed the threshold value, the pressure applied to the permeable membrane is made larger than the previous time, the adjustment step, the acquisition step, and the determination Repeating steps to perform, and
It is characterized by having.

The invention according to claim 8 provides:
In the concentration measurement system,
A supply layer to which a gas sample containing a detection target substance is supplied, a detection layer that is disposed adjacent to the supply layer and contains a receptor that selectively reacts with the detection target substance, the supply layer, and the supply layer A biosensor that is disposed so as to be separated from the detection layer and has at least a permeable membrane that allows the detection target substance to pass therethrough, and an electrode that is disposed on the detection layer so as to face the permeable membrane;
Adjusting means for adjusting the pressure applied to the permeable membrane by adjusting the flow rate of the gas sample supplied to the supply layer;
Measurement means for measuring the concentration of the detection target substance based on detection result data related to the detection result by the biosensor, and the flow rate of the gas sample adjusted by the adjustment means,
The measuring means includes
Adjustment control means for adjusting the adjustment means so that the flow rate of the gas sample supplied to the supply layer has a predetermined size;
Obtaining means for obtaining response data relating to the response output of the biosensor;
A determination unit that determines whether a value based on the response data acquired by the acquisition unit exceeds a predetermined threshold corresponding to a flow rate of the gas sample supplied to the supply layer;
A determination unit that determines the response data as the detection result data when the determination unit determines that the value based on the response data exceeds the threshold;
The adjustment control means adjusts the adjustment so that when the determination means determines that the value based on the response data does not exceed the threshold, the flow rate of the gas sample supplied to the supply layer is larger than the previous time. It is characterized by making a means adjust.

The invention according to claim 9 is:
In the concentration measurement system,
A supply layer to which a gas sample containing a detection target substance is supplied, a detection layer that is disposed adjacent to the supply layer and contains a receptor that selectively reacts with the detection target substance, the supply layer, and the supply layer A biosensor that is disposed so as to be separated from the detection layer and has at least a permeable membrane that allows the detection target substance to pass therethrough, and an electrode that is disposed on the detection layer so as to face the permeable membrane;
Adjusting means for adjusting the pressure applied to the permeable membrane by adjusting the pressure in the supply layer;
Measuring means for measuring the concentration of the substance to be detected based on detection result data relating to the detection result by the biosensor, and the pressure in the supply layer adjusted by the adjusting means,
The measuring means includes
Adjustment control means for adjusting the adjustment means so that the pressure in the supply layer has a predetermined magnitude;
Obtaining means for obtaining response data relating to the response output of the biosensor;
Determining means for determining whether a value based on the response data acquired by the acquiring means exceeds a predetermined threshold corresponding to the pressure in the supply layer;
A determination unit that determines the response data as the detection result data when the determination unit determines that the value based on the response data exceeds the threshold;
The adjustment control unit causes the adjustment unit to adjust the pressure in the supply layer to be larger than the previous time when the determination unit determines that the value based on the response data does not exceed the threshold value. It is characterized by that.

According to the present invention, in the concentration measurement system, the supply layer to which the fluid sample containing the detection target substance is supplied, the detection layer disposed adjacent to the supply layer, and the supply layer and the detection layer are separated from each other. A sensor having at least a permeable membrane through which a substance to be detected permeates and an electrode disposed on the detection layer so as to face the permeable membrane, an adjusting means for adjusting a pressure applied to the permeable membrane, and detection result data relating to a detection result by the sensor Measuring means for measuring the concentration of the detection target substance based on the pressure applied to the permeable membrane adjusted by the adjusting means.
Here, since the membrane permeability of the detection target substance depends on the pressure applied to the permeable membrane, the detection concentration range of the sensor can be changed by adjusting the pressure applied to the permeable membrane by the adjusting means. Therefore, the sensor can be used as a sensor having a wide detection concentration range with a simple configuration of adjusting the pressure applied to the permeable membrane, and even if the concentration of the detection target substance is unknown, the pressure applied to the permeable membrane can be reduced. The concentration of the detection target substance can be measured by detecting the detection target substance at an appropriate pressure in the variable range (pressure that becomes an appropriate detection concentration range).

Further, according to the present invention, the supply layer to which the fluid sample containing the detection target substance is supplied, the detection layer arranged to be adjacent to the supply layer, and the supply layer and the detection layer are arranged to be separated from each other. In a method for measuring a concentration of a detection target substance using a sensor having at least a permeable membrane through which the detection target substance permeates and an electrode disposed on the detection layer opposite to the permeable film, the pressure applied to the permeable membrane is predetermined. An adjustment step for adjusting to a magnitude of the sensor, an acquisition step for acquiring response data relating to the response output of the sensor, and then a value based on the acquired response data is a predetermined threshold value corresponding to the pressure applied to the permeable membrane A determination step for determining whether or not the value exceeds the threshold, and when the determination step determines that the value based on the response data exceeds the threshold, the response data is related to the detection result by the sensor. A determination step for determining as detection result data, and an adjustment step and an acquisition step when the value based on the response data is determined not to exceed the threshold value in the determination step and the pressure applied to the permeable membrane is made larger than the previous time. And a determination step, and a repetition step for performing the determination step.
Here, since the membrane permeability of the substance to be detected depends on the pressure applied to the permeable membrane, the detection concentration range of the sensor can be changed by adjusting the pressure applied to the permeable membrane. Therefore, by adjusting the pressure applied to the permeable membrane and determining whether or not the adjusted pressure is within the appropriate detection concentration range based on a predetermined threshold, Even if the concentration is unknown, the detection target substance can be detected and the concentration of the detection target substance can be measured.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The scope of the invention is not limited to the illustrated example.
In the present embodiment, an enzyme sensor will be exemplified and described as a sensor (biosensor).

[First Embodiment]
First, the concentration measurement system 1000 and the concentration measurement method in the first embodiment will be described.

<Concentration measurement system>
FIG. 1 is a diagram illustrating a configuration of the concentration measurement system 1000, and FIG. 2 is a diagram illustrating a functional configuration of the concentration measurement system 1000. 3 is a plan perspective view of the enzyme sensor 10, FIG. 4 is a diagram schematically showing a cross section taken along line IV-IV in FIG. 3, and FIG. 5 is an exploded view of the enzyme sensor 10. .
Here, the supply layer L1 side in the enzyme sensor 10 is the upper side, the detection layer L2 side is the lower side, the side on which the pad 250 is disposed is the front side, and the opposite side is the rear side. The orthogonal direction is defined as the left-right direction.

The concentration measurement system 1000 is a system that detects the detection target substance using the enzyme sensor 10 and measures the concentration of the detection target substance, for example.
Specifically, the concentration measurement system 1000 includes, for example, an enzyme sensor 10, a measurement circuit 21, a data processing device 22, a data display device 23, and a standard gas generation device 31 as shown in FIGS. And an intake pump 32, a valve drive device 40, a flow meter 51, a control device 60, and the like.

<Enzyme sensor>
The enzyme sensor 10 includes an electrode 240, and is a sensor that detects a detection target substance in a gas sample by an electrochemical measurement method using characteristics of the enzyme. The enzyme sensor 10 includes a supply layer L1 to which a gas (a gas sample or a standard gas) containing a detection target substance is supplied, and a detection layer L2 to which a predetermined electrolyte is introduced. It is arrange | positioned at the detection layer L2, and the enzyme is contained in the detection layer L2.
In the enzyme sensor 10, the enzyme is contained in the detection layer L2 in the state of a free enzyme. That is, for example, by using an electrolyte containing an enzyme as the electrolyte introduced into the detection layer L2, the enzyme is contained in the detection layer L2.

  Specifically, for example, as shown in FIGS. 3 to 5, the enzyme sensor 10 includes a supply layer L1 to which a gas sample or a standard gas as a fluid sample containing a detection target substance is supplied, and a supply layer L1. It arrange | positions so that the detection layer L2 containing the enzyme as a receptor which is arrange | positioned adjacently and reacts selectively with a detection target substance, and supply layer L1 and the detection layer L2 may be spaced apart, and at least a detection target substance permeate | transmits. A permeable membrane 400, an electrode 240 disposed on the detection layer L2 so as to face the permeable membrane 400, a deformation preventing member 500 disposed on the upper surface of the permeable membrane 400 and preventing the permeable membrane 400 from being deformed, and the like. Composed.

  More specifically, the enzyme sensor 10 includes, for example, a case body 100, an electrode substrate portion 200 accommodated in the case body 100, a packing 300, a permeable membrane 400, a deformation preventing member 500, and the like. .

The case body 100 includes, for example, a lower case body 110 and an upper case body 120 that are formed by dividing a substantially cylindrical body in a direction (horizontal direction) perpendicular to the vertical direction at a substantially central position in the vertical direction, and a lower case. A plurality of connecting members 130 for connecting the body 110 and the upper case body 120, and the like.
The material constituting the case body 100 is preferably a material having high corrosion resistance to an electrolyte solution or a sample (for example, a hydrophobic insulating material, an insulating material whose surface is subjected to hydrophobic treatment, etc.). For example, ceramics, glass, plastic, Teflon (registered trademark), peak material, and the like can be used.

In the lower case body 110, for example, a liquid storage part 111 for storing the electrolytic solution introduced into the enzyme sensor 10 and an electrolysis for introducing the electrolytic solution from the outside of the enzyme sensor 10 toward the liquid storage part 111. The liquid inlet 112, the electrolytic solution introduction path 113 communicating with the liquid reservoir 111 and the electrolytic solution inlet 112, and the electrolytic solution drain for discharging the electrolytic solution from the liquid reservoir 111 to the outside of the enzyme sensor 10 An outlet 114, an electrolyte discharge path 115 that communicates with the liquid reservoir 111 and the electrolyte discharge port 114, a placement portion 116 for placing the electrode substrate portion 200, and a plurality of connection members 130 that can be inserted therein A recess 117 and the like are provided.
Here, in particular, the surface of the lower case body 110, the liquid reservoir 111, the electrolytic solution introduction port 112, the electrolytic solution introduction passage 113, the electrolytic solution discharge port 114, the electrolytic solution discharge passage 115, etc. It is preferable to be formed of a material having high corrosion resistance to the material (for example, a hydrophobic insulating material, an insulating material whose surface is subjected to hydrophobic treatment, etc.).

The liquid reservoir 111 is, for example, a substantially circular recess in a plan view formed at an approximately central position in the horizontal direction of the lower case body 110 and having an open upper surface.
In addition, the electrolyte solution introduction path 113 is formed, for example, from the liquid reservoir 111 to the rear side in the left direction.
Moreover, the electrolyte solution discharge path 115 is formed, for example, from the liquid reservoir 111 toward the rear side in the right direction.
The mounting portion 116 is, for example, a recessed portion that is formed from the substantially horizontal center position of the lower case body 110 toward the front side and has an open upper surface.
Moreover, the recessed part 117 is a recessed part of the substantially circular shape in planar view formed in the upper surface edge part of the lower case body 110 with the upper surface opened, for example.
Moreover, the depth of the liquid storage part 111 and the mounting part 116 is set to be substantially the same as the thickness of the electrode substrate part 200, for example.

The upper case body 120 is provided with, for example, a gas supply port 121 through which a gas sample or standard gas is supplied from the outside of the enzyme sensor 10, a plurality of holes 122 through which the connecting member 130 can pass, and the like. .
Here, in particular, the surface of the upper case body 120, the gas supply port 121, and the like are made of a material having high corrosion resistance to an electrolyte solution or a sample (for example, a hydrophobic insulating material, an insulating material whose surface is subjected to hydrophobic treatment, or the like). ).

The gas supply port 121 is, for example, a substantially circular through hole that is formed in a position corresponding to the liquid reservoir 111 of the lower case body 110 in the upper case body 120 and penetrates in the vertical direction.
The hole 122 is, for example, a substantially circular through hole that is formed in a position corresponding to the concave portion 117 of the lower case body 110 in the upper case body 120 and penetrates in the vertical direction.

  For example, the connecting member 130 can penetrate the hole 122 and can be inserted into the recess 117, and the lower case body 110 and the upper case body 120 form the electrode substrate portion 200, the packing 300, the permeable membrane 400, and the deformation. The lower case body 110 and the upper case body 120 are connected by inserting the connecting member 130 from the upper side to the lower side of the hole portion 122 and inserting the connecting member 130 into the recess 117 with the prevention member 500 interposed therebetween. It is supposed to be. As a result, the electrode substrate unit 200, the packing 300, the permeable membrane 400, and the deformation prevention member 500 are accommodated in the case body 100.

  Here, in the state where the electrode substrate unit 200, the packing 300, the permeable membrane 400, and the deformation preventing member 500 are accommodated in the case body 100, the inside of the supply port 121 of the upper case body 120 becomes the supply layer L1, and the lower case body 110. The inside of the liquid reservoir 111 and the inside of the opening 310 of the packing 300 serve as the detection layer L2.

For example, as shown in FIG. 5, the electrode substrate unit 200 includes a substrate 210, a hydrophobic insulating film 230 having an opening (analysis unit 220) provided on the upper surface of the substrate 210, and analysis on the upper surface of the substrate 210. Electrode 240 (working electrode 241, counter electrode 242, and reference electrode 243) disposed inside portion 220, pad 250 provided corresponding to electrode 240, and wiring 260 connecting electrode 240 and pad 250, , And so on.
The electrode substrate unit 200 is mounted on the mounting unit 116 of the lower case body 110 such that the pad 250 is disposed outside the case body 100, for example.
In addition, the electrode substrate part 200 does not need to be provided with the hydrophobic insulating film 230 which has an opening part (analysis part 220).

The packing 300 is, for example, for sealing the detection layer L2 and preventing the electrolyte introduced into the detection layer L2 from leaking.
The material constituting the packing 300 is preferably a material having high corrosion resistance to an electrolytic solution or a sample, and specifically includes an elastic member such as a silicon rubber sheet.

Specifically, the packing 300 is formed, for example, in a substantially ring shape in plan view having an opening 310, and a plurality of holes 320 through which the connecting member 130 can pass are provided at the edge of the packing 300. ing.
The opening 310 is, for example, a substantially circular through hole in a plan view that is formed in a position corresponding to the liquid reservoir 111 of the lower case body 110 in the packing 300 and penetrates in the vertical direction.
The hole 320 is, for example, a substantially circular through hole that is formed in a position corresponding to the recess 117 of the lower case body 110 in the packing 300 and penetrates in the vertical direction.
The packing 300 is disposed on the upper surface of the lower case body 110 so that the hole 320 corresponds to the concave portion 117 of the lower case body 110, for example. The connecting member 130 is passed through the portion 320.

For example, the permeable membrane 400 is disposed on the upper surface of the packing 300 so as to cover the opening 310. That is, the supply layer L1 and the detection layer L2 are separated by the permeable membrane 400.
The detection target substance supplied to the supply layer L1 passes through the permeable membrane 400, moves to the detection layer L2, and reacts with the enzyme contained in the detection layer L2. Therefore, the permeable membrane 400 is arbitrary as long as it is a film through which at least the detection target substance permeates, and can be appropriately changed depending on the type of detection target substance.
In particular, in the concentration measurement system 1000, since a gas sample or standard gas is supplied to the supply layer L1, the detection target substance (detection target gas) passes through the permeable membrane 400, but the electrolyte solution that satisfies the detection layer L2 is A gas permeable membrane that does not permeate is preferred.

For example, the deformation preventing member 500 is disposed on the upper surface of the permeable membrane 400 so as to cover the opening 310 of the packing 300.
The deformation preventing member 500 is for preventing deformation of the permeable membrane 400 during use of the enzyme sensor 10. Specifically, in order to improve the strength of the permeable membrane 400 and prevent deformation, for example, the permeable membrane 400 and the deformation preventing member 500 are overlapped to form an electrode substrate portion in the permeable membrane 400 and the deformation preventing member 500. The parts other than the part corresponding to the analysis unit 220 of 200 are adhered, and the permeable membrane 400 and the deformation preventing member 500 are integrated. As a result, the distance between the electrode 240 and the permeable membrane 400 can be kept constant.
The material constituting the deformation preventing member 500 is arbitrary as long as the deformation preventing member 500 can prevent the deformation of the permeable membrane 400, and specifically includes, for example, a mesh body such as a stainless mesh.
Here, as long as the deformation preventing member 500 can prevent the deformation of the permeable membrane 400, the deformation preventing member 500 may be disposed on the lower surface of the permeable membrane 400, or sandwich the permeable membrane 400. You may arrange | position at the upper surface and lower surface of the permeable film 400. FIG.

The enzyme contained in the detection layer L2 is arbitrary as long as it is an enzyme that selectively reacts with the detection target substance, and can be appropriately changed depending on the type of the detection target substance.
Specifically, the enzyme is an enzyme (enzyme protein) such as an oxidoreductase, a hydrolase, a transferase, and an isomerase.
The enzyme may be, for example, a natural enzyme molecule or an enzyme fragment containing an active site. The enzyme molecule or the fragment of the enzyme containing the active site is synthesized, for example, genetically or chemically, whether it is extracted from animals or plants or microorganisms, or is cleaved if desired. It may be a thing.

  Examples of the oxidoreductase include glucose oxidase, lactate oxidase, cholesterol oxidase, alcohol oxidase, formaldehyde oxidase, sorbitol oxidase, fructose oxidase, sarcosine oxidase, fructosylamine oxidase, pyruvate oxidase, xanthine oxidase, ascorbate oxidase, sarcosine. Oxidase, choline oxidase, amine oxidase, glucose dehydrogenase, lactate dehydrogenase, cholesterol dehydrogenase, alcohol dehydrogenase, formaldehyde dehydrogenase, sorbitol dehydrogenase, fructose dehydrogenase, hydroxybutyrate dehydrogenase, glycerol dehydrogenase Glutamate dehydrogenase, pyruvate dehydrogenase, malate dehydrogenase, glutamate dehydrogenase, can be used catalase, peroxidase, uricase, and the like. In addition, cholesterol esterase, creatininase, creatinase, DNA polymerase, mutants of these enzymes, and the like can be used.

  As the hydrolase, for example, protease, lipase, amylase, invertase, maltase, β-galactosidase, lysozyme, urease, esterase, nuclease group, phosphatase group and the like can be used.

  As the transferase, for example, various acyltransferases, kinase groups, aminotransferase groups and the like can be used.

  As the isomerase, for example, racemase group, phosphoglycerate phosphomutase, glucose 6-phosphate isomerase and the like can be used.

The enzyme contained in the detection layer L2 may be one type of enzyme or two or more types of enzymes.
Specifically, the enzyme contained in the detection layer L2 may be, for example, one kind of enzyme or two or more kinds of enzymes having substantially the same molecular weight and / or size (diameter). Two or more enzymes having different sizes may be used. In addition, when there are two or more types of enzymes contained in the detection layer L2, for example, even if the enzymes are two or more types of enzymes that act on the same type of detection target substance (substrate), Even two or more types of enzymes that act may be two or more types of enzymes that act on the same type and / or different types of detection target substances.
Here, in particular, when there are two or more types of enzymes contained in the detection layer L2 and the two or more types of enzymes act on different types of detection target substances, for example, the detection potential is changed or the electrode substrate part 200 is used. By arranging a plurality of electrodes 240 (working electrodes 241) in the analysis unit 220, the enzyme sensor 10 can simultaneously detect the different types of detection target substances (two or more types of detection target substances).

<Measurement circuit>
For example, the measurement circuit 21 applies a voltage to the enzyme sensor 10 according to a control signal input from the control device 60, measures a response current from the enzyme sensor 10 (response output of the enzyme sensor 10), and returns response data. Create

<Data processing device>
For example, the data processing device 22 processes the response data created by the measurement circuit 21 in accordance with a control signal input from the control device 60, and creates numerical data based on the response data.
Here, the numerical data is arbitrary as long as it is data related to numerical values such as response current and concentration (concentration of the detection target substance calculated from the response current and a calibration curve prepared in advance). It may be data relating to numerical values such as the density and density, or data relating to changes in numerical values.

<Data display device>
For example, the data display device 23 displays numerical information based on the numerical data created by the data processing device 22 in accordance with a control signal input from the control device 60.
Here, the numerical information may be, for example, numerical values such as response current and concentration, or graphs of changes in numerical values (for example, a graph showing a calibration curve or a graph showing changes in numerical values over time). It may be.

<Standard gas generator>
For example, the standard gas generation device 31 generates a standard gas having a substrate concentration designated by the control device 60 in accordance with a control signal input from the control device 60.
Here, the standard gas (the gas containing the substrate (detection target substance)) is used, for example, when preparing a calibration curve.

<Intake pump>
The intake pump 32, for example, inhales a gas sample such as the external atmosphere or a standard gas generated by the standard gas generation device 31 in accordance with a control signal input from the control device 60, and supplies it to the supply layer L1 of the enzyme sensor 10. Supply.
Specifically, the intake side of the intake pump 32 is connected to, for example, a predetermined region (a region where a gas sample such as the external atmosphere exists) and the standard gas generation device 31 via a switching valve 41 with a tube. The exhaust side is connected to, for example, a supply-side flow rate adjustment valve 42 via a tube. For example, the intake pump 32 supplies the intake gas to the supply port 121 (supply layer L <b> 1) so as to be blown to the permeable membrane 400 of the enzyme sensor 10 through the supply-side flow rate adjustment valve 42 and the flow meter 51. It is like that.
Note that the spray angle of gas (gas sample or standard gas) to the permeable membrane 400 is arbitrary as long as it is 0 degree or more and 90 degrees or less. However, the pressure applied to the permeable film 400 is increased to allow the detection target substance to permeate. From the viewpoint of facilitating, 45 degrees or more is preferable.

<Valve drive device>
The valve drive device 40 drives each valve (the switching valve 41, the supply side flow rate adjustment valve 42, etc.) included in the concentration measurement system 1000 according to a control signal input from the control device 60, for example.

  The switching valve 41 is, for example, a gas supplied to the supply layer L1 of the enzyme sensor 10 (that is, a gas sucked into the intake pump 32), a gas sample such as the external atmosphere, and a standard generated by the standard gas generator 31. For example, a predetermined region (a region where a gas sample such as the external atmosphere exists) and the standard gas generation device 31 and the intake side of the intake pump 32 are arranged. Yes.

The supply-side flow rate adjustment valve 42 is a valve for adjusting the flow rate of the gas supplied to the supply layer L1 of the enzyme sensor 10, such as a needle valve, for example, and for example, the exhaust side of the intake pump 32 and the flow meter 51. And is arranged between.
Here, the adjusting means for adjusting the pressure applied to the permeable membrane 400 by adjusting the flow rate of the gas sample supplied to the supply layer L <b> 1 is configured by, for example, the valve drive device 40 and the supply-side flow rate adjustment valve 42.

<Flow meter>
The flow meter 51 measures the flow rate of the gas supplied to the supply layer L1 of the enzyme sensor 10, for example.

<Control device>
The control device 60 is, for example, a device for controlling each device constituting the concentration measurement system 1000.
Specifically, for example, as illustrated in FIG. 2, the control device 60 includes a CPU (Central Processing Unit) 61, a RAM (Random Access Memory) 62, a storage unit 63, and the like.

  For example, the CPU 61 performs various control operations in accordance with various processing programs for the control device 60 stored in the storage unit 63.

  The RAM 62 includes, for example, a program storage area for expanding a processing program executed by the CPU 61, a data storage area for storing input data, a processing result generated when the processing program is executed, and the like.

  The storage unit 63 includes, for example, a system program that can be executed by the control device 60, various processing programs that can be executed by the system program, data that is used when these various processing programs are executed, and processing results that are arithmetically processed by the CPU 61. The data etc. are memorized. The program is stored in the storage unit 63 in the form of a computer readable program code.

  Specifically, the storage unit 63 stores, for example, a calibration curve creation program 63a, a threshold determination program 63b, a measurement program 63c, and the like.

  For example, the calibration curve creation program 63a causes the CPU 61 to realize a function of creating a calibration curve used when measuring the concentration of the detection target substance.

  Specifically, for example, the CPU 61 inputs a control signal to the valve driving device 40 and switches the switching valve 41 so that the standard gas generated by the standard gas generating device 31 is supplied to the enzyme sensor 10. .

  Next, the CPU 61 inputs a control signal to the valve driving device 40 based on the flow rate measured by the flow meter 51, for example, and supplies the flow rate adjustment valve 42 on the supply side so that the standard gas is supplied to the enzyme sensor 10 at a constant flow rate. The control signal is input to the standard gas generation device 41 and the intake pump 32 while adjusting the gas, so that standard gases having different substrate concentrations are sequentially generated and supplied to the enzyme sensor 10 sequentially, and the measurement circuit 21 and the data processing device 22 are supplied. Input a control signal to create a calibration curve.

The CPU 61 performs this series of processing for each of a plurality of flow rates (for example, “flow rate Fa”, “flow rate Fb”,...), For example. That is, for example, the CPU 61 creates a calibration curve corresponding to each of a plurality of flow rates (a calibration curve corresponding to “flow rate Fa”, a calibration curve corresponding to “flow rate Fb”,...).
The created calibration curve is stored in, for example, the RAM 62 or the storage unit 63.

  For example, the threshold value determination program 63b causes the CPU 61 to realize a function of determining a predetermined threshold value used when measuring the concentration of the detection target substance.

Specifically, for example, the CPU 61 determines a detection density range based on a calibration curve created by the CPU 61 that has executed the calibration curve creation program 63a, and a response corresponding to one density within the determined detection density range. The current is determined as a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 (that is, a predetermined threshold corresponding to the flow rate of the gas sample supplied to the supply layer L1).
Here, the detection concentration range is a concentration range used in calculating the concentration of the detection target substance in the concentration range in the calibration curve, and is, for example, a concentration range having a linear detection range. .

More specifically, for example, when a calibration curve as shown in FIG. 6 is created as a calibration curve corresponding to “flow rate Fa”, the detected concentration range is determined as C1 to C3, and the determined detected concentration range is determined. “Response current I2” corresponding to one of the concentrations C2 is determined as a threshold corresponding to “flow rate Fa”.
In FIG. 6, one concentration C2 is arbitrary as long as it is within the detection concentration range C1 to C3.

For example, the measurement program 63 c causes the CPU 61 to realize a function of measuring the concentration of the detection target substance using the enzyme sensor 10.
That is, the CPU 61 is based on, for example, detection result data related to the detection result by the enzyme sensor 10 and the pressure applied to the adjusted permeable membrane 400 (that is, the flow rate of the gas sample supplied to the adjusted supply layer L1). To measure the concentration of the detection target substance.

  Specifically, for example, the CPU 61 inputs a control signal to the valve driving device 40 and switches the switching valve 41 so that a gas sample such as external air is supplied to the enzyme sensor 10.

Next, the CPU 61 inputs a control signal to the valve driving device 40 based on the flow rate measured by the flow meter 51, for example, so that the pressure applied to the permeable membrane 400 becomes a predetermined magnitude (that is, the supply layer L1). A control signal is input to the intake pump 32 while the supply-side flow rate adjustment valve 42 is adjusted so that the flow rate of the gas sample to be supplied becomes a predetermined magnitude, and the gas sample is supplied to the enzyme sensor 10.
More specifically, for example, the flow rate of the gas sample supplied to the supply layer L1 is a flow rate (for example, “flow rate Fa”, “flow rate Fb” corresponding to the calibration curve created by the CPU 61 that executes the calibration curve creation program 63a. ”,... (Fa <Fb <...)) Is adjusted to be the same as the smallest flow rate (“ flow rate Fa ”).

  Next, for example, the CPU 61 inputs a control signal to the measurement circuit 21 and measures response current from the enzyme sensor 10 (response output of the enzyme sensor 10), thereby acquiring response data regarding the response output of the enzyme sensor 10. To do.

Next, the CPU 61, for example, has a predetermined value corresponding to the pressure applied to the permeable membrane 400 among predetermined threshold values determined by the CPU 61 that executes the threshold value determination program 63b, based on the acquired response data (response current value). It is determined whether or not a threshold value (that is, a predetermined threshold value corresponding to the flow rate of the gas sample supplied to the supply layer L1) has been exceeded.
More specifically, for example, a calibration curve as shown in FIG. 6 is created as a calibration curve corresponding to “flow rate Fa”, and the flow rate of the gas sample supplied to the supply layer L1 is adjusted to “flow rate Fa”. Then, it is determined whether or not the value based on the acquired response data exceeds a predetermined threshold “response current I2” corresponding to the flow rate “flow rate Fa” of the gas sample supplied to the supply layer L1.

  And when it is judged that the value based on response data exceeded the predetermined threshold value, CPU61 determines the said response data as detection result data regarding the detection result by the enzyme sensor 10, for example.

  Next, the CPU 61, for example, inputs a control signal to the data processing device 22, and numerical data based on the response data (that is, a value based on the response data (response current value) and a gas sample supplied to the supply layer L1. Data relating to the concentration of the detection target substance calculated from the calibration curve corresponding to the flow rate of the gas, a control signal is input to the data display device 23, and numerical information based on the numerical data (that is, the detection target substance) Display).

On the other hand, when determining that the value based on the response data does not exceed the predetermined threshold, the CPU 61, for example, increases the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1) from the previous time. Then, the above series of processing (adjustment-acquisition-determination) is repeated until the detection result data regarding the detection result by the enzyme sensor 10 is determined.
More specifically, for example, the flow rate of the gas sample supplied to the supply layer L1 is a flow rate (for example, “flow rate Fa”, “flow rate Fb” corresponding to the calibration curve created by the CPU 61 that executes the calibration curve creation program 63a. ,... (Fa <Fb <...)), The flow rate is adjusted to be the same as the flow rate next to the previous flow rate (for example, “flow rate Fa”) (“flow rate Fb”).
The CPU 61 functions as a measurement unit, an adjustment control unit, an acquisition unit, a determination unit, and a determination unit by executing the measurement program 63c.

<Concentration measurement method>
An example of the concentration measurement method of the detection target substance using the enzyme sensor 10 by the concentration measurement system 1000 will be described with reference to the flowchart of FIG.

  First, the CPU 61 executes the calibration curve creation program 63a to supply the standard gas to the enzyme sensor 10 while adjusting the flow rate of the standard gas to be supplied to the supply layer L1 to be the first flow rate. A calibration curve corresponding to is created (step S11).

  Next, the CPU 61 supplies the standard gas to the enzyme sensor 10 while adjusting the flow rate of the standard gas supplied to the supply layer L1 to be a second flow rate larger than the first flow rate, and the calibration corresponding to the second flow rate. A line is created (step S12).

  Next, the CPU 61 supplies the standard gas to the enzyme sensor 10 while adjusting the flow rate of the standard gas supplied to the supply layer L1 to be a third flow rate larger than the second flow rate, and the calibration corresponding to the third flow rate. A line is created (step S13).

Next, the CPU 61 executes the threshold value determination program 63b to determine a first threshold value corresponding to the first flow rate and a second threshold value corresponding to the second flow rate based on the created calibration curve (step S14).
Here, a predetermined threshold value (third threshold value) corresponding to the largest flow rate (third flow rate) among the flow rates corresponding to the created calibration curve may be determined.

  Next, the CPU 61 executes the measurement program 63c to supply the gas sample to the enzyme sensor 10 while adjusting the flow rate of the gas sample supplied to the supply layer L1 to be the first flow rate (step S15), and to respond. Data is acquired (step S16), and it is determined whether or not the value based on the acquired response data exceeds the first threshold (step S17).

  If it is determined in step S17 that the value based on the acquired response data exceeds the first threshold (step S17; Yes), the CPU 61 proceeds to the process of step S23.

  On the other hand, if it is determined in step S17 that the value based on the acquired response data does not exceed the first threshold value (step S17; No), the CPU 61 determines that the flow rate of the gas sample supplied to the supply layer L1 is the second flow rate. The gas sample is supplied to the enzyme sensor 10 (step S18), response data is acquired (step S19), and whether or not the value based on the acquired response data exceeds the second threshold Is determined (step S20).

  If it is determined in step S20 that the value based on the acquired response data exceeds the second threshold (step S20; Yes), the CPU 61 proceeds to the process of step S23.

  On the other hand, when it is determined in step S20 that the value based on the acquired response data does not exceed the second threshold value (step S20; No), the CPU 61 determines that the flow rate of the gas sample supplied to the supply layer L1 is the third flow rate. The gas sample is supplied to the enzyme sensor 10 (step S21), and response data is acquired (step S22).

Next, the CPU 61 determines the acquired response data as detection result data related to the detection result by the enzyme sensor 10 (step S23), calculates and displays the concentration of the detection target substance (step S24), and ends this process. .
Specifically, when the response data acquired when the flow rate of the gas sample is the first flow rate is determined as detection result data, a value based on the response data and a calibration curve corresponding to the first flow rate Then, the concentration of the detection target substance is calculated.
Moreover, when the response data acquired when the flow rate of the gas sample is the second flow rate is determined as detection result data, a value based on the response data and a calibration curve corresponding to the second flow rate are used. Calculate the concentration of the detection target substance.
Further, when the response data acquired when the flow rate of the gas sample is the third flow rate is determined as detection result data, a value based on the response data and a calibration curve corresponding to the third flow rate are used. Calculate the concentration of the detection target substance.

  Here, the adjustment step of adjusting the pressure applied to the permeable membrane 400 to a predetermined magnitude corresponds to step S15, and the acquisition step of acquiring response data related to the response output of the enzyme sensor 10 corresponds to step S16. The determination step for determining whether the value based on the acquired response data exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 corresponds to step S17, and the value based on the response data is predetermined in the determination step. The determination step of determining the response data as detection result data related to the detection result by the enzyme sensor 10 when it is determined that the threshold value of the enzyme sensor 10 has been exceeded corresponds to step S23, and is adjusted with the determined detection result data. The calculation step of calculating the concentration of the detection target substance based on the pressure applied to the permeable membrane 400 includes step S 4, when it is determined in the determination step that the value based on the response data does not exceed a predetermined threshold value, the pressure applied to the permeable membrane 400 is made larger than the previous time, and the adjustment step (step S 18, step S 21). ), An acquisition step (step S19, step S22), and a determination step (step S20), the repetition step corresponds to step S18 to step S22.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto.

  The enzyme sensor 10 was created and the concentration measurement system 1000 was evaluated.

<1> Production of enzyme sensor 10 In this example, an enzyme sensor 10 for detecting formaldehyde gas was produced. As the enzyme, formaldehyde dehydrogenase (formaldehyde dehydrogenase), which is a coenzyme (NAD ⁺ ) -dependent enzyme, was used.

<1-1> Creation of Electrode Substrate Part 200 First, an electrode substrate part 200 having a tripolar structure pattern of a working electrode 241, a counter electrode 242, and a reference electrode 243 was created.
Specifically, a glass substrate formed in a substantially rectangular shape was prepared as the substrate 210, carbon was applied to the substrate 210 by screen printing, and post-baked at 120 ° C. for 15 minutes using a hot plate. Further, by applying an ultraviolet curable insulating film to the region corresponding to the analysis unit 220 in the substrate 210 and a portion other than the pad 250 by screen printing, and curing the ultraviolet curable insulating film using an ultraviolet exposure device, A hydrophobic insulating film 230 was created.
Then, it was made to dry in a dark room overnight, the silver / silver chloride ink was apply | coated on the pattern of the reference electrode 243, and it sintered at 120 degreeC, and produced the reference electrode 243 which is a silver / silver chloride electrode.

<1-2> Creation of enzyme sensor 10 First, the case body 100 (the lower case body 110 and the upper case body 120) was created by processing a peak material that is an insulator using a lathe, a milling machine, or the like. .
The depth of the liquid storage part 111 and the mounting part 116 was set to be substantially the same as the thickness (0.8 mm) of the electrode substrate part 200.

Next, the created electrode substrate 200 is arranged such that the analysis unit 220 is disposed in the liquid storage unit 111 and the pad 250 is disposed outside the enzyme sensor 10. It was mounted on the mounting portion 116 and fixed to the lower case body 110.
The method of fixing the electrode substrate part 200 to the lower case body 110 may be a method of sealing and fixing using a tape member such as Teflon tape, or a method of bonding and fixing using an adhesive or the like. May be.

Next, the lower case body 110 was placed on the stage T1.
Specifically, for example, as shown in FIG. 8, the lower case body 110 on which the electrode substrate unit 200 is mounted is fixed on the stage T1 using screws or the like (not shown).

  Next, a silicon rubber sheet (thickness: 50 μm) having a hole portion 320 formed in a substantially ring shape in plan view is prepared as the packing 300, and the packing portion 300 has a recess portion 117 of the lower case body 110. It was installed on the lower case body 110 so as to correspond to the above.

Next, as a permeable membrane 400, a gas permeable membrane (made by Gore-Tex) formed in a substantially circular shape in plan view is prepared, and as a deformation preventing member 500, a stainless mesh formed in a substantially circular shape in plan view is prepared, The permeable membrane 400 and the deformation preventing member 500 covered the opening 310 of the packing 300.
Here, in order to improve the strength of the permeable membrane 400, the permeable membrane 400 and the deformation preventing member 500 are overlapped, and the portion of the permeable membrane 400 and the deformation preventing member 500 corresponding to the analysis unit 220 of the electrode substrate unit 200. The permeable membrane 400 and the deformation preventing member 500 were integrated with each other. The permeable membrane 400 and the deformation preventing member 500 are integrated to cover the opening 310 of the packing 300.

  Next, the created upper case body 120 is placed on the packing 300 such that the hole 122 corresponds to the concave portion 117 of the lower case body 110, and the connecting case 130 is used to attach the upper case body 120 to the lower case body 110. Connected. Then, for example, as shown in FIG. 8, the position of the upper case body 120 is fixed by the holder T2.

Next, an electrolytic solution was introduced into the detection layer L2.
Specifically, 1.0 U formaldehyde dehydrogenase, 0.5 μmol NAD ⁺ , and 20 μmol naphthaquinone were dissolved in 2000 μL phosphate buffer (pH 7.5) to prepare an enzyme solution. The detection solution L2 was filled with the enzyme solution by continuously introducing the enzyme solution from the electrolyte solution inlet 112 into the enzyme sensor 10 using a syringe until leakage from the electrolyte outlet 114. At this time, about 1000 μL of the enzyme solution was introduced into the enzyme sensor 10.

<2> Evaluation of Concentration Measurement System 1000 In this example, the enzyme sensor 10 was measured by applying a voltage of +350 mV to the working electrode 241 with respect to the reference electrode 243 at room temperature (25 ° C.) and measuring the current by amperometry. Response current (response output of the enzyme sensor 10) was measured.

<2-1> Flow Dependency of Response Current An experiment was conducted to evaluate the flow dependency of the response current from the enzyme sensor 10 created above.
Specifically, a standard gas having a formaldehyde concentration of 10 ppb was generated and sequentially supplied while changing the flow rate, and the response current was measured. The result is shown in FIG.

In FIG. 9, the horizontal axis represents the flow rate (sccm: standard cc / min (1 × 10 ⁻⁶ m ³ / min)), and the vertical axis represents the response current (nA) in the equilibrium state.
According to FIG. 9, it was found that the response current from the enzyme sensor 10 increases when the flow rate of the gas supplied to the supply layer L1 increases.

  From the result of FIG. 9, it was found that the sensitivity of the enzyme sensor 10 is increased by increasing the flow rate of the gas supplied to the supply layer L1.

<2-2> Creation of calibration curve Using the enzyme sensor 10 created above, an experiment for creating a calibration curve was performed.
Specifically, standard gases having different formaldehyde concentrations were sequentially generated and supplied at a constant flow rate, and the response current was measured. This series of processing was performed for each of a plurality of flow rates (100 sccm, 300 sccm, 500 sccm). The result is shown in FIG.

In FIG. 10, the horizontal axis shows formaldehyde concentration (ppb), the vertical axis shows the response current (nA) in the equilibrium state, the flow rate is 100 sccm in the rhombus (♦) plot, and the flow rate is shown in the square (■) plot. As a result when the flow rate is 300 sccm, the result when the flow rate is 500 sccm is shown by a triangle (▲) plot.
According to FIG. 10, when the flow rate was 100 sccm, it was found that the detected concentration range was 10 ppb to 10000 ppb.
Moreover, when the flow rate was 300 sccm, it was found that the detection concentration range was 1 ppb to 100 ppb.
Moreover, when the flow rate was 500 sccm, it was found that the detection concentration range was 0.1 ppb to 10 ppb.

  From the result of FIG. 10, when the flow rate of the gas supplied to the supply layer L1 is constant, the detection concentration range is narrow, but the detection concentration range of the enzyme sensor 10 changes by changing the flow rate of the gas supplied to the supply layer L1. I found out that Therefore, by changing the flow rate of the gas supplied to the supply layer L1, the enzyme sensor 10 can be used as a sensor having a wide detection concentration range, and an appropriate one of the variable ranges of the flow rate of the gas supplied to the supply layer L1. It was found that the concentration of the detection target substance can be measured by detecting the detection target substance at a high flow rate (flow rate that provides an appropriate detection concentration range).

  Formaldehyde in the formaldehyde gas supplied to the supply layer L1 passes through the permeable membrane 400, moves from the supply layer L1 to the detection layer L2, dissolves in the electrolytic solution, and reacts with the enzyme. Finally, the electron carrier is oxidized on the working electrode 241. Since the membrane permeability of the detection target substance depends on the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1), the sensitivity of the enzyme sensor 10 depends on the pressure applied to the permeable membrane 400 (that is, It is considered that it varies depending on the flow rate of the gas sample supplied to the supply layer L1.

  Here, if a predetermined threshold value corresponding to the flow rate of the gas sample supplied to the supply layer L1 is determined based on the calibration curve shown in FIG. 10, for example, from the calibration curve corresponding to 100 sccm (first flow rate). The response current (90 nA) corresponding to one concentration (for example, 200 ppb) in the determined detected concentration range of 10 ppb to 10000 ppb may be determined as a threshold (first threshold) corresponding to 100 sccm, for example, 300 sccm ( The response current (40 nA) corresponding to one concentration (for example, 10 ppb) in the detected concentration range 1 ppb to 100 ppb determined from the calibration curve corresponding to the second flow rate) is a threshold corresponding to 300 sccm (second threshold). As long as it is determined.

According to the concentration measurement system 1000 in the first embodiment described above, the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1) is adjusted to a predetermined magnitude, and the enzyme sensor The response data regarding 10 response outputs was acquired, and the value based on the acquired response data exceeded a predetermined threshold value corresponding to the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1). If it is determined that the value based on the acquired response data exceeds the predetermined threshold, the response data is determined as detection result data, and the value based on the acquired response data is The pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1) is larger than the previous time. The above series of processes Te by repeatedly performing the (adjusted - - obtaining judgment) until determining the detection result data relating to the detection result by the enzyme sensor 10 is adapted to measure the concentration of the target substance.
Here, since the membrane permeability of the detection target substance depends on the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1), the flow rate of the gas sample supplied to the supply layer L1 is adjusted. Thus, the detection concentration range of the enzyme sensor 10 can be changed. Therefore, the enzyme sensor 10 can be used as a sensor having a wide detection concentration range with a simple configuration of adjusting the flow rate of the gas sample supplied to the supply layer L1, and the concentration of the detection target substance is unknown. , Detecting the substance to be detected at an appropriate flow rate (flow rate within an appropriate detection concentration range) in the variable range of the flow rate of the gas sample supplied to the supply layer L1, and measuring the concentration of the detection target substance Can do.

Further, according to the concentration measurement system 1000 in the first embodiment described above, the enzyme sensor 10 is disposed on at least one surface (upper surface and / or lower surface) of the permeable membrane 400 to prevent deformation of the permeable membrane 400. A deformation preventing member 500 is provided.
Therefore, the deformation preventing member 500 can prevent the deformation of the permeable membrane 400 and can keep the distance between the electrode 240 (electrode substrate unit 200) and the permeable membrane 400 constant. It can be performed stably.

According to the concentration measurement method in the first embodiment described above, an adjustment step for adjusting the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1) to a predetermined magnitude; An acquisition step of acquiring response data relating to the response output of the enzyme sensor 10 and a value based on the acquired response data corresponding to a pressure applied to the permeable membrane 400 (that is, a flow rate of the gas sample supplied to the supply layer L1). A determination step for determining whether or not a threshold value of the enzyme sensor 10 has been exceeded, and when it is determined in the determination step that the value based on the response data has exceeded a predetermined threshold value, the response data Determining step, determining detection result data, and pressure applied to the permeable membrane 400 adjusted by the adjusting means That is, the value based on the response data in the calculation step for calculating the concentration of the detection target substance based on the flow rate of the gas sample supplied to the adjusted supply layer L1 and the determination step does not exceed a predetermined threshold value When it is determined that the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1) is larger than the previous time, the adjustment step, the acquisition step, and the determination step are repeated. And steps.
Therefore, the detection target substance is adjusted with a simple configuration in which the pressure applied to the permeable membrane 400 is adjusted, and it is determined whether the adjusted pressure is a pressure within an appropriate detection concentration range based on a predetermined threshold. Even if the concentration is unknown, the detection target substance can be detected and the concentration of the detection target substance can be measured.

[Second Embodiment]
Next, the concentration measurement system 1000A and the concentration measurement method in the second embodiment will be described.
The concentration measurement system 1000A of the second embodiment differs from the enzyme sensor 10 provided in the concentration measurement system 1000 of the first embodiment in the configuration of the enzyme sensor 10A. Therefore, only different parts will be described, and other common parts will be denoted by the same reference numerals and detailed description thereof will be omitted.

<Concentration measurement system>
FIG. 11 is a diagram showing a configuration of the concentration measurement system 1000A, and FIG. 12 is a diagram showing a functional configuration of the concentration measurement system 1000A. 13 is a plan perspective view of the enzyme sensor 10A, FIG. 14 is a diagram schematically showing a cross section taken along line XIV-XIV in FIG. 13, and FIG. 15 is taken along line XV-XV in FIG. It is a figure which shows a cross section typically. 16A is a bottom view of the upper support 820 in a state where the permeable membrane 400 is attached, and FIG. 16B is a plan view of the lower support 810 in a state where the electrode substrate portion 200A is attached. FIG.

The concentration measurement system 1000A is a system that detects the detection target substance using the enzyme sensor 10A and measures the concentration of the detection target substance, for example.
Specifically, the concentration measurement system 1000A includes, for example, an enzyme sensor 10A, a measurement circuit 21, a data processing device 22, a data display device 23, and a standard gas generation device 31, as shown in FIGS. And an intake pump 32, a valve drive device 40, a flow meter 51, a control device 60, and the like.

<Enzyme sensor>
The enzyme sensor 10A is a sensor that is detachably provided with an electrode substrate portion 200A having an electrode 240A, and detects a detection target substance in a gas sample by an electrochemical measurement method using the characteristics of the enzyme. The enzyme sensor 10A includes a supply layer L1 to which a gas (a gas sample or a standard gas) containing a detection target substance is supplied, and a detection layer L2 to which a predetermined electrolytic solution is introduced. It is arrange | positioned at the detection layer L2, and the enzyme is contained in the detection layer L2.
In the enzyme sensor 10A, the enzyme is contained in the detection layer L2 in the state of a free enzyme. That is, for example, by using an electrolyte containing an enzyme as the electrolyte introduced into the detection layer L2, the enzyme is contained in the detection layer L2.

  Specifically, for example, as shown in FIGS. 13 to 16, the enzyme sensor 10 </ b> A includes a support body 800 including a lower support body 810 and an upper support body 820, and a gas sample or standard containing a detection target substance. The supply layer L1 to which the gas is supplied, the detection layer L2 that is disposed adjacent to the supply layer L1, and contains an enzyme that selectively reacts with the detection target substance, and the supply layer L1 and the detection layer L2 are separated from each other. And a first O-ring 610 for fixing the permeable membrane 400 to the upper support 820 and a size (diameter) for defining the size (diameter) of the detection layer L2. An electrode substrate portion 200A having a 2O ring 620, an electrode 240A disposed on the detection layer L2 facing the permeable membrane 400, and disposed between the permeable membrane 400 and the electrode substrate portion 200A (electrode 240A). Configured to include a spacer 700 that the permeable membrane 400 supports the permeable membrane 400 so as not to deform, and the like.

For example, the support body 800 is formed by cutting out a part of a side surface of the substantially cylindrical body along the vertical direction so as to have a substantially D shape in plan view, and in the vertical direction at a position below the vertical center. A lower support body 810 and an upper support body 820 formed by dividing in an orthogonal direction (horizontal direction), a plurality of screws 830 for fixing the upper support body 820 to the lower support body 810, and the like. Configured.
The material constituting the support 800 is preferably a material having high corrosion resistance to an electrolytic solution or a sample (for example, a hydrophobic insulating material, an insulating material having a hydrophobic surface), specifically, For example, ceramics, glass, plastic, Teflon, peak material, etc. can be used.

The lower support 810 is provided with, for example, an attachment portion 811 for detachably attaching the electrode substrate portion 200A.
Here, in particular, the surface of the lower support 810, the mounting portion 811, and the like are made of a material having high corrosion resistance to an electrolyte solution or a sample (for example, a hydrophobic insulating material, an insulating material whose surface is subjected to hydrophobic treatment, etc.) ).

The attachment portion 811 is, for example, a concave portion that is formed from the substantially horizontal center position of the lower support 810 toward the front side and has an open upper surface.
The depth of the attachment portion 811 is set to be substantially the same as the thickness of the electrode substrate portion 200A, for example.

  The upper support 820 is formed to be, for example, a dome shape that bulges upward, and a concave portion 821 having an open lower surface is provided at a substantially central position in the horizontal direction of the upper support 820. .

The concave portion 821 is, for example, a first concave portion 821b having a substantially circular shape in plan view, in which the position of the bottom surface (the surface facing the opening surface) separated by the partition wall 821a is above the substantially vertical center of the upper support 820. And a second concave portion 821c having a substantially ring shape in plan view, the position of the bottom surface (the surface facing the opening surface) being below the substantially vertical center of the upper support 820.
For example, when the permeable membrane 400 is attached to the upper support 820, the first recess 821b is separated in the vertical direction, and the region above the first recess 821b in the separated state is a gas phase. It becomes a chamber (supply layer L1), and the lower region of the first recess 821b and the second recess 821c become the liquid phase chamber (detection layer L2). Therefore, the distance between the electrode 240A (electrode substrate part 200A) and the permeable membrane 400 is defined by the height (length in the vertical direction) of the partition wall 821a.

Specifically, the upper support 820 includes, for example, a recess 821, an O-ring housing portion 822 that is disposed around the recess 821 and has a substantially ring shape in plan view with an open bottom surface, and air from the outside of the enzyme sensor 10A. A gas introduction port 831 for introducing a gas (a gas sample or a standard gas) toward the phase chamber (supply layer L1), a gas introduction path 832 communicating the gas phase chamber and the gas introduction port 831, and a gas phase chamber A gas discharge port 833 for discharging gas from the enzyme sensor 10A to the outside of the enzyme sensor 10A, a gas discharge path 834 communicating the gas phase chamber and the gas discharge port 833, and a liquid phase chamber (detection from the outside of the enzyme sensor 10A) An electrolyte solution introduction port 841 for introducing an electrolyte solution toward the layer L2), an electrolyte solution introduction path 842 that communicates the liquid phase chamber and the electrolyte solution introduction port 841, and from the liquid phase chamber to the outside of the enzyme sensor 10A. To discharge the electrolyte With the electrolyte outlet 843, and the electrolyte discharge channel 844 which communicates the liquid phase chamber and the electrolyte outlet 843, and the like are provided.
Here, in particular, the surface of the upper support 820, the recess 821, the gas inlet 831, the gas inlet 832, the gas outlet 833, the gas outlet 834, the electrolyte inlet 841, the electrolyte inlet 842, the electrolyte The discharge port 843, the electrolyte solution discharge path 844, and the like are formed of a material having high corrosion resistance to the electrolyte solution or the sample (for example, a hydrophobic insulating material, an insulating material whose surface is subjected to hydrophobic treatment, etc.). preferable.

The gas introduction path 832 is formed, for example, upward from the first recess 821b in the left direction. The angle of the gas introduction path 832 with respect to the permeable membrane 400 is arbitrary as long as it is 0 degree or more and 90 degrees or less, but from the viewpoint of increasing the pressure applied to the permeable film 400 to facilitate the permeation of the detection target substance. 45 degrees or more is preferable.
The gas discharge path 834 is formed, for example, upward from the first recess 821b in the right direction.
In addition, the electrolyte solution introduction path 842 is, for example, a first line formed in the vertical direction in a region from the upper surface of the second concave portion 821c behind the first concave portion 821b to a position approximately in the center in the vertical direction of the upper support 820. An electrolyte solution introduction path 842a and a second electrolyte solution introduction path 842b formed rearward and upward from the first electrolyte solution introduction path 842a.
Further, the electrolyte discharge path 844 is, for example, a first formed along the vertical direction in a region from the upper surface of the second concave portion 821c in front of the first concave portion 821b to a position approximately at the center in the vertical direction of the upper support 820. An electrolyte solution discharge path 844a, and a second electrolyte solution discharge path 844b formed from the first electrolyte solution discharge path 844a to the upper side in the forward direction.

For example, as shown in FIG. 16, the electrode substrate portion 200A corresponds to the substrate 210, the electrode 240A (the working electrode 241A, the counter electrode 242A, and the reference electrode 243A) disposed on the upper surface of the substrate 210, and the electrode 240A. A pad 250, a wiring 260 for connecting the electrode 240A and the pad 250, and the like are provided.
The electrode substrate portion 200A is attached to the attachment portion 811 by inserting it into the attachment portion 811 from the front of the enzyme sensor 10A, for example.
The electrode substrate portion 200A may include a hydrophobic insulating film 230 having an opening (analysis portion 220).

  For example, the permeable membrane 400 covers the first concave portion 821b from the lower surface side of the upper support 820 with the permeable membrane 400, and the first O-ring 610 is disposed on the lower surface side of the permeable membrane 400 and moved upward to move the partition wall 821a. Is attached to the upper support 820.

The first O-ring 610 is for attaching the permeable membrane 400 to the upper support 820, for example.
The second O-ring 620 is for defining the horizontal size (diameter) of the liquid phase chamber (detection layer L2), for example, and the detection layer L2 is sealed and introduced into the detection layer L2. This is to prevent leakage of the electrolyte solution, and is accommodated in the O-ring accommodating portion 822. Accordingly, the second O-ring 620 is preferably, for example, one having a thickness equal to or greater than the height (length in the vertical direction) of the O-ring housing portion 822.
As a material constituting the first O-ring 610 and the second O-ring 620, a material having high corrosion resistance against an electrolytic solution or a sample is preferable.

The spacer 700 is disposed on the upper surface of the electrode substrate portion 200A so as to substantially cover the electrode 240A, for example.
The spacer 700 is for supporting the permeable membrane 400 so that the permeable membrane 400 is not deformed during use of the enzyme sensor 10A. Therefore, as the spacer 700, for example, a spacer having a thickness equivalent to the distance between the electrode 240A (electrode substrate portion 200A) and the permeable membrane 400 is preferable. As a result, the distance between the electrode 240A and the permeable membrane 400 can be kept constant.
The material constituting the spacer 700 is arbitrary as long as it can support the permeable membrane 400 so as not to be deformed by the spacer 700 and has good substrate (detection target substance) permeability. Examples thereof include a porous body such as an anodic oxide film having a plurality of through-holes penetrating substantially perpendicular to the electrode 240A, a hydrophilic film such as a hydrophilic Teflon film, and a mesh body such as a nylon mesh.

  Here, in the first embodiment, the gas (gas sample or standard gas) sucked by the suction pump 32 is blown onto the permeable membrane 400 of the enzyme sensor 10 to supply the supply port 121 (supply layer L1). In the second embodiment, for example, as shown in FIG. 11, the exhaust side of the intake pump 32 and the enzyme sensor 10A (the gas inlet 831 of the enzyme sensor 10A) are A gas is supplied to the gas phase chamber (supply layer L1) by connecting with a tube via the supply-side flow rate adjustment valve 42 and the flow meter 51 and introducing the gas sucked by the intake pump 32 from the gas introduction port 831. It has become.

<Concentration measurement method>
An example of the concentration measurement method for the detection target substance using the enzyme sensor 10A by the concentration measurement system 1000A is the concentration measurement method for the detection target substance using the enzyme sensor 10 according to the concentration measurement system 1000 of the first embodiment. Since it is substantially the same as (FIG. 7), detailed description is abbreviate | omitted.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto.

  The enzyme sensor 10A was created and the concentration measurement system 1000A was evaluated.

<1> Preparation of enzyme sensor 10A In this example, an enzyme sensor 10A for detecting formaldehyde gas was prepared. As the enzyme, formaldehyde dehydrogenase (formaldehyde dehydrogenase), which is a coenzyme (NAD ⁺ ) -dependent enzyme, was used.

<1-1> Creation of Electrode Substrate Part 200 First, an electrode substrate part 200A having a tripolar pattern of the working electrode 241A, the counter electrode 242A, and the reference electrode 243A was created.
Specifically, a glass substrate formed in a substantially rectangular shape was prepared as the substrate 210, carbon was applied to the substrate 210 by screen printing, and post-baked at 120 ° C. for 15 minutes using a hot plate.
Thereafter, the film was dried overnight in a dark room, and a silver / silver chloride ink was applied onto the pattern of the reference electrode 243A and sintered at 120 ° C. to prepare a reference electrode 243A that is a silver / silver chloride electrode.
The electrode substrate portion 200A is coated with an ultraviolet curable insulating film on the substrate 210 other than the region corresponding to the analysis portion 220 and the pad 250 by screen printing, as in the first embodiment of the first embodiment. The hydrophobic insulating film 230 may be formed by applying and curing the ultraviolet curable insulating film using an ultraviolet exposure device.

<1-2> Creation of Enzyme Sensor 10A First, the support 800 (the lower support 810 and the upper support 820) was created by processing a peak material that is an insulator using a lathe or a milling machine. .
The depth of the mounting portion 811 was set to be substantially the same as the thickness (0.8 mm) of the electrode substrate portion 200A. Further, the height of the partition wall 821a was adjusted so that the distance between the permeable membrane 400 and the electrode 240A was 50 μm.

  Next, a hydrophobic porous Teflon membrane made of PTFE was prepared as the permeable membrane 400, and the permeable membrane 400 was fixed to the upper support 820 using the first O-ring 610. Further, the second O-ring 620 was accommodated in the O-ring accommodating portion 822.

  Next, a hydrophilic Teflon membrane (thickness: 50 μm, manufactured by Millipore) having a thickness substantially the same as the distance (50 μm) between the permeable membrane 400 and the electrode 240A is prepared as the spacer 700, and a liquid phase chamber (detection layer L2) Placed in.

  Next, the upper support 820 is disposed on the lower support 810, the upper support 820 is fixed to the lower support 820 using screws 830, and the electrode substrate part 200A created as described above is attached to the attachment part 811. It was.

Next, an electrolytic solution was introduced into the detection layer L2.
Specifically, first, the electrolyte solution inlet 841 of the enzyme sensor 10A is connected to the electrolyte solution tank by a tube via a liquid feed pump, and the electrolyte solution discharge port 843 is connected to the electrolyte solution tank and / or the waste solution. Connected with tank and tube.
Next, an enzyme solution is prepared by dissolving 20 mg of formaldehyde dehydrogenase in a phosphate buffer (pH 7.41) containing 1 mM NAD ⁺ and 1 mM quinone, and the enzyme solution is placed in the electrolyte tank. I put it in.
Next, using the liquid feed pump, the electrolytic solution in the electrolytic solution tank is introduced from the electrolytic solution introduction port 841 into the enzyme sensor 10A, and the electrolytic solution discharge port 843 and the tank (the electrolytic solution tank and / or the waste solution) are introduced. The detection layer L2 was filled with the enzyme solution by continuing to introduce until the tube connecting the tank) was filled with the electrolyte.

<2> Evaluation of Concentration Measurement System 1000A In this example, the enzyme sensor 10A is measured by applying a voltage of +350 mV to the working electrode 241A with respect to the reference electrode 243A at room temperature (25 ° C.) and measuring the current by amperometry. Response current (response output of the enzyme sensor 10A) was measured.

<2-1> Flow Dependency of Response Current An experiment was performed to evaluate the flow dependency of the response current from the enzyme sensor 10A created above.
Specifically, a standard gas having a formaldehyde concentration of 10 ppb was generated and sequentially supplied while changing the flow rate, and the response current was measured. The result is shown in FIG.

In FIG. 17, the horizontal axis represents the flow rate (sccm), and the vertical axis represents the response current (nA) in the equilibrium state.
According to FIG. 17, it was found that the response current from the enzyme sensor 10A increases as the flow rate of the gas supplied to the supply layer L1 increases.

  From the result of FIG. 17, it was found that the sensitivity of the enzyme sensor 10A is increased by increasing the flow rate of the gas supplied to the supply layer L1.

<2-2> Creation of Calibration Curve An experiment for creating a calibration curve was performed using the enzyme sensor 10A created above.
Specifically, standard gases having different formaldehyde concentrations were sequentially generated and supplied at a constant flow rate, and the response current was measured. This series of processing was performed for each of a plurality of flow rates (100 sccm, 300 sccm, 500 sccm). The result is shown in FIG.

In FIG. 18, the horizontal axis represents formaldehyde concentration (ppb), the vertical axis represents the response current (nA) in an equilibrium state, the flow rate is 100 sccm in the rhombus (♦) plot, and the flow rate in the square (■) plot. As a result when the flow rate is 300 sccm, the result when the flow rate is 500 sccm is shown by a triangle (▲) plot.
According to FIG. 18, when the flow rate was 100 sccm, it was found that the detected concentration range was 10 ppb to 10000 ppb.
Moreover, when the flow rate was 300 sccm, it was found that the detection concentration range was 1 ppb to 100 ppb.
Moreover, when the flow rate was 500 sccm, it was found that the detection concentration range was 0.1 ppb to 10 ppb.

  From the result of FIG. 18, when the flow rate of the gas supplied to the supply layer L1 is constant, the detection concentration range is narrow, but by changing the flow rate of the gas supplied to the detection layer L1, the detection concentration range of the enzyme sensor 10A changes. I found out that Therefore, by changing the flow rate of the gas supplied to the supply layer L1, the enzyme sensor 10A can be used as a sensor having a wide detection concentration range, and an appropriate one of the variable ranges of the flow rate of the gas supplied to the supply layer L1. It was found that the concentration of the detection target substance can be measured by detecting the detection target substance at a high flow rate (flow rate that provides an appropriate detection concentration range).

  Formaldehyde in the formaldehyde gas supplied to the supply layer L1 passes through the permeable membrane 400, moves from the supply layer L1 to the detection layer L2, dissolves in the electrolytic solution, and reacts with the enzyme. Finally, the electron carrier is oxidized on the working electrode 241A. Since the membrane permeability of the detection target substance depends on the pressure applied to the permeable membrane 400 (that is, the flow rate of the gas sample supplied to the supply layer L1), the sensitivity of the enzyme sensor 10A depends on the pressure applied to the permeable membrane 400 (that is, It is considered that it varies depending on the flow rate of the gas sample supplied to the supply layer L1.

According to the concentration measurement system 1000A in the second embodiment described above, the enzyme sensor 10A is disposed between the permeable membrane 400 and the electrode 240A, and supports the permeable membrane 400 so that the permeable membrane 400 does not deform. A spacer 700 is provided.
Therefore, the spacer 700 can prevent the deformation of the permeable membrane 400 and can keep the distance between the electrode 240A (electrode substrate portion 200A) and the permeable membrane 400 constant, so that the detection of the detection target substance can be stabilized. Can be done.

[Third Embodiment]
Next, the concentration measurement system 1000B and the concentration measurement method in the third embodiment will be described.
Note that the concentration measurement system 1000B of the third embodiment differs from the concentration measurement system 1000A of the second embodiment in the manner of adjusting the pressure applied to the permeable membrane 400. Therefore, only different parts will be described, and other common parts will be denoted by the same reference numerals and detailed description thereof will be omitted.

<Concentration measurement system>
FIG. 19 is a diagram illustrating a configuration of the concentration measurement system 1000B, and FIG. 20 is a diagram illustrating a functional configuration of the concentration measurement system 1000B.

The concentration measurement system 1000B is a system that measures the concentration of the detection target substance by measuring the detection target substance using the enzyme sensor 10A, for example.
Specifically, the concentration measurement system 1000B includes, for example, an enzyme sensor 10A, a measurement circuit 21, a data processing device 22, a data display device 23, and a standard gas generation device 31, as shown in FIGS. And an intake pump 32, a valve drive device 40B, a pressure gauge 52, a control device 60B, and the like.

<Valve drive device>
For example, the valve drive device 40B drives each valve (the switching valve 41, the supply side flow rate adjustment valve 42, the discharge side flow rate adjustment valve 43, etc.) included in the concentration measurement system 1000B in accordance with a control signal input from the control device 60B. To do.

The discharge-side flow rate adjustment valve 43 is a valve for adjusting the flow rate of gas discharged from the supply layer L1 of the enzyme sensor 10A, such as a needle valve, for example, and includes, for example, a gas discharge port 833 of the enzyme sensor 10A, Connected with a tube.
Therefore, in the second embodiment, the gas (gas sample or standard gas) supplied to the enzyme sensor 10A is directly discharged to the outside from the gas discharge port 833. In this embodiment, the gas is discharged from the gas discharge port 833 to the outside through the discharge side flow rate adjustment valve 43.
Here, the adjusting means for adjusting the pressure applied to the permeable membrane by adjusting the flow rate of the gas sample supplied to the supply layer L1 and adjusting the pressure in the supply layer L1 is, for example, the valve driving device 40B, the supply The side flow rate adjusting valve 42 and the discharge side flow rate adjusting valve 43 are configured.

<Pressure gauge>
The pressure gauge 52 measures the pressure in the supply layer L1 of the enzyme sensor 10A, for example.

<Control device>
The control device 60B is, for example, a device for controlling each device constituting the concentration measurement system 1000B.
Specifically, for example, as illustrated in FIG. 20, the control device 60B includes a CPU 61, a RAM 62, a storage unit 63B, and the like.

  The calibration curve creation program 63aB causes the CPU 61 to realize a function for creating a calibration curve used when measuring the concentration of the detection target substance, for example.

  Specifically, for example, the CPU 61 inputs a control signal to the valve driving device 40B, and switches the switching valve 41 so that the standard gas generated by the standard gas generating device 31 is supplied to the enzyme sensor 10A. .

  Next, the CPU 61 inputs a control signal to the valve drive device 40B based on the pressure measured by the pressure gauge 52, for example, and supplies the supply-side flow rate adjustment valve 42 and the discharge-side flow rate so that the supply layer L2 has a constant pressure. While adjusting the adjustment valve 43, a control signal is input to the standard gas generation device 41 and the intake pump 32 to sequentially generate standard gases having different substrate concentrations and supply them sequentially to the enzyme sensor 10A. A control signal is input to the apparatus 22 to create a calibration curve.

The CPU 61 performs this series of processes for each of a plurality of pressures (for example, “pressure Pa”, “pressure Pb”,...), For example. That is, for example, the CPU 61 creates a calibration curve corresponding to each of a plurality of pressures (a calibration curve corresponding to “pressure Pa”, a calibration curve corresponding to “pressure Pb”,...).
The created calibration curve is stored in, for example, the RAM 62 or the storage unit 63B.

  The threshold value determining program 63bB causes the CPU 61 to realize a function of determining a predetermined threshold value used when measuring the concentration of the detection target substance, for example.

  Specifically, for example, the CPU 61 determines a detected concentration range based on a calibration curve created by the CPU 61 that has executed the calibration curve creation program 63aB, and a response corresponding to one concentration within the determined detected concentration range. The current is determined as a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 (that is, a predetermined threshold corresponding to the pressure in the supply layer L1).

More specifically, for example, when a calibration curve as shown in FIG. 6 is created as a calibration curve corresponding to “pressure Pa”, the detected concentration range is determined as C1 to C3, and the determined detected concentration range is determined. The “response current I2” corresponding to one concentration C2 is determined as a threshold corresponding to “pressure Pa”.
In FIG. 6, one concentration C2 is arbitrary as long as it is within the detection concentration range C1 to C3.

For example, the measurement program 63cB causes the CPU 61 to realize a function of measuring the concentration of the detection target substance using the enzyme sensor 10A.
That is, the CPU 61 detects, for example, the detection target substance based on the detection result data regarding the detection result by the enzyme sensor 10A and the pressure applied to the adjusted permeable membrane 400 (that is, the adjusted pressure in the supply layer L1). Measure the concentration.

  Specifically, for example, the CPU 61 inputs a control signal to the valve driving device 40B, and switches the switching valve 41 so that a gas sample such as external air is supplied to the enzyme sensor 10A.

Next, the CPU 61 inputs a control signal to the valve driving device 40B based on the pressure measured by the pressure gauge 52, for example, so that the pressure applied to the permeable membrane 400 becomes a predetermined magnitude (that is, in the supply layer L1). While adjusting the supply side flow rate adjustment valve 42 and the discharge side flow rate adjustment valve 43 (so that the pressure of the gas reaches a predetermined level), a control signal is input to the intake pump 32 to supply the gas sample to the enzyme sensor 10A.
More specifically, for example, the pressure in the supply layer L1 corresponds to a pressure curve (for example, “pressure Pa”, “pressure Pb”,...) Corresponding to the calibration curve created by the CPU 61 that executes the calibration curve creation program 63aB. Pa <Pb <...)) Is adjusted to be the same as the smallest pressure (“pressure Pa”).

  Next, for example, the CPU 61 inputs a control signal to the measurement circuit 21 and measures response current from the enzyme sensor 10A (response output of the enzyme sensor 10A), thereby acquiring response data regarding the response output of the enzyme sensor 10A. To do.

Next, the CPU 61, for example, has a predetermined value corresponding to the pressure applied to the permeable membrane 400 among the predetermined threshold values determined by the CPU 61 that executes the threshold value determination program 63bB based on the acquired response data (response current value). It is determined whether or not a threshold value (that is, a predetermined threshold value corresponding to the pressure in the supply layer L1) has been exceeded.
More specifically, for example, when a calibration curve as shown in FIG. 6 is created as a calibration curve corresponding to “pressure Pa” and the pressure in the supply layer L1 is adjusted to “pressure Pa”, the acquired response is obtained. It is determined whether or not the value based on the data exceeds a predetermined threshold “response current I2” corresponding to the pressure “pressure Pa” in the supply layer L1.

  And when it is judged that the value based on response data exceeded the predetermined threshold value, CPU61 determines the said response data as detection result data regarding the detection result by 10 A of enzyme sensors, for example.

  Next, for example, the CPU 61 inputs a control signal to the data processing device 22 and corresponds to numerical data based on the response data (that is, a value based on the response data (response current value) and a pressure in the supply layer L1. Data relating to the concentration of the detection target substance calculated from the calibration curve to be generated), a control signal is input to the data display device 23, and numerical information based on the numerical data (that is, the concentration of the detection target substance) is obtained. Display.

On the other hand, when determining that the value based on the response data does not exceed the predetermined threshold, the CPU 61 increases the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1) from the previous time, for example. A series of processing (adjustment-acquisition-determination) is repeated until detection result data relating to a detection result by the enzyme sensor 10A is determined.
More specifically, for example, the pressure in the supply layer L1 corresponds to a pressure curve (for example, “pressure Pa”, “pressure Pb”,...) Corresponding to the calibration curve created by the CPU 61 that executes the calibration curve creation program 63aB. Pa <Pb <...)) Is adjusted to be the same as the pressure (“pressure Pb”) next to the previous pressure (for example, “pressure Pa”).
The CPU 61 functions as a measurement unit, an adjustment control unit, an acquisition unit, a determination unit, and a determination unit by executing the measurement program 63cB.

<Concentration measurement method>
An example of the concentration measurement method for the detection target substance using the enzyme sensor 10A by the concentration measurement system 1000B will be described with reference to the flowchart of FIG.

  First, the CPU 61 executes the calibration curve creation program 63aB and supplies the standard gas to the enzyme sensor 10A while adjusting the pressure in the supply layer L1 to be the first pressure, and the calibration corresponding to the first pressure. A line is created (step S31).

  Next, the CPU 61 supplies the standard gas to the enzyme sensor 10 while adjusting the pressure in the supply layer L1 to be a second pressure larger than the first pressure, and creates a calibration curve corresponding to the second pressure. (Step S32).

  Next, the CPU 61 supplies the standard gas to the enzyme sensor 10 while adjusting the pressure in the supply layer L1 to be a third pressure larger than the second pressure, and creates a calibration curve corresponding to the third pressure. (Step S33).

Next, the CPU 61 executes the threshold value determination program 63bB to determine a first threshold value corresponding to the first pressure and a second threshold value corresponding to the second pressure based on the created calibration curve (step S34).
Here, a predetermined threshold value (third threshold value) corresponding to the largest pressure (third pressure) among the pressures corresponding to the created calibration curve may be determined.

  Next, the CPU 61 executes the measurement program 63cB, supplies the gas sample to the enzyme sensor 10A while adjusting the pressure in the supply layer L1 to be the first pressure (step S35), and obtains response data. (Step S36), it is determined whether or not the value based on the acquired response data exceeds the first threshold (Step S37).

  If it is determined in step S37 that the value based on the acquired response data exceeds the first threshold (step S37; Yes), the CPU 61 proceeds to the process of step S43.

  On the other hand, if it is determined in step S37 that the value based on the acquired response data does not exceed the first threshold value (step S37; No), the CPU 61 adjusts the pressure in the supply layer L1 to be the second pressure. Meanwhile, the gas sample is supplied to the enzyme sensor 10A (step S38), response data is acquired (step S39), and it is determined whether or not the value based on the acquired response data exceeds the second threshold ( Step S40).

  If it is determined in step S40 that the value based on the acquired response data exceeds the second threshold (step S40; Yes), the CPU 61 proceeds to the process of step S43.

  On the other hand, if it is determined in step S40 that the value based on the acquired response data does not exceed the second threshold value (step S40; No), the CPU 61 adjusts the pressure in the supply layer L1 to be the third pressure. While supplying the gas sample to the enzyme sensor 10A (step S41), the response data is acquired (step S44).

Next, the CPU 61 determines the acquired response data as detection result data related to the detection result by the enzyme sensor 10A (step S43), calculates and displays the concentration of the detection target substance (step S44), and ends this process. .
Specifically, when the response data acquired when the pressure in the supply layer L1 is the first pressure is determined as the detection result data, it corresponds to the value based on the response data and the first pressure. The concentration of the detection target substance is calculated from the calibration curve.
In addition, when the response data acquired when the pressure in the supply layer L1 is the second pressure is determined as detection result data, a value based on the response data and a calibration curve corresponding to the second pressure From the above, the concentration of the detection target substance is calculated.
In addition, when the response data acquired when the pressure in the supply layer L1 is the third pressure is determined as detection result data, a value based on the response data and a calibration curve corresponding to the third pressure From the above, the concentration of the detection target substance is calculated.

  Here, the adjustment step of adjusting the pressure applied to the permeable membrane 400 to a predetermined magnitude corresponds to step S35, and the acquisition step of acquiring response data regarding the response output of the enzyme sensor 10A corresponds to step S36. The determination step for determining whether the value based on the acquired response data exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 corresponds to step S37, and the value based on the response data is predetermined in the determination step. The determination step of determining the response data as the detection result data related to the detection result by the enzyme sensor 10A when it is determined that the threshold value is exceeded corresponds to step S43 and adjusted with the determined detection result data. The calculation step of calculating the concentration of the detection target substance based on the pressure applied to the permeable membrane 400 is a step. Corresponding to S44, when it is determined in the determination step that the value based on the response data does not exceed the predetermined threshold value, the pressure applied to the permeable membrane 400 is made larger than the previous time, and the adjustment step (step S38, step S41). ), An acquisition step (step S39, step S42), and a determination step (step S40) correspond to step S38 to step S42.

According to the concentration measurement system 1000B in the third embodiment described above, the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1) is adjusted to a predetermined magnitude, and the response output of the enzyme sensor 10A is output. Is obtained by determining whether or not a value based on the obtained response data exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1). If it is determined that the value based on the response data exceeds the predetermined threshold, the response data is determined as detection result data, and the value based on the acquired response data is determined not to exceed the predetermined threshold. In this case, the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1) is increased from the previous time, and the above series of processing (adjustment-acquisition-determination) is By repeatedly be performed until determining the detection result data relating to the detection result by the capacitors 10A, it is adapted to measure the concentration of the target substance.
Here, since the membrane permeability of the detection target substance depends on the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1), the detection concentration of the enzyme sensor 10A is adjusted by adjusting the pressure in the supply layer L1. The range can be changed. Accordingly, the enzyme sensor 10A can be used as a sensor having a wide detection concentration range with a simple configuration of adjusting the pressure in the supply layer L1, and even if the concentration of the detection target substance is unknown, the supply layer L1 The concentration of the detection target substance can be measured by detecting the detection target substance at an appropriate pressure (pressure within an appropriate detection concentration range) within the variable range of the internal pressure.

  Further, according to the concentration measuring system 1000B in the third embodiment described above, the supply is performed by adjusting the flow rate of the gas supplied to the supply layer L1 and the flow rate of the gas discharged from the supply layer L1. Since the pressure in the layer L1 is adjusted, the pressure in the supply layer L1 can be reliably adjusted with a simple configuration.

According to the concentration measuring method in the third embodiment described above, the adjustment step of adjusting the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1) to a predetermined magnitude, and the enzyme sensor 10A An acquisition step of acquiring response data related to the response output, and whether or not a value based on the acquired response data exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1). A determination step for determining, and a determination step for determining the response data as detection result data relating to a detection result by the enzyme sensor 10A when the value based on the response data is determined to exceed a predetermined threshold value in the determination step; Detection result data and the pressure applied to the permeable membrane 400 adjusted by the adjusting means (that is, the pressure in the supply layer L1) The pressure applied to the permeable membrane 400 when the value based on the response data is determined not to exceed a predetermined threshold value (ie, the supply layer) (Pressure in L1) is made larger than the previous time, and an adjustment step, an acquisition step, and a determination step are repeated.
Therefore, the detection target substance is adjusted with a simple configuration in which the pressure applied to the permeable membrane 400 is adjusted, and it is determined whether the adjusted pressure is a pressure within an appropriate detection concentration range based on a predetermined threshold. Even if the concentration is unknown, the detection target substance can be detected and the concentration of the detection target substance can be measured.

[Fourth Embodiment]
Next, a concentration measurement system 1000C and a concentration measurement method in the fourth embodiment will be described.
Note that the concentration measurement system 1000C of the fourth embodiment differs from the concentration measurement system 1000B of the third embodiment in the way of adjusting the pressure in the supply layer L1. Therefore, only different parts will be described, and other common parts will be denoted by the same reference numerals and detailed description thereof will be omitted.

<Concentration measurement system>
FIG. 22 is a diagram illustrating a configuration of the concentration measurement system 1000C, and FIG. 23 is a diagram illustrating a functional configuration of the concentration measurement system 1000C.

The concentration measurement system 1000C is a system that measures the concentration of the detection target substance by measuring the detection target substance using, for example, the enzyme sensor 10A.
Specifically, the concentration measurement system 1000C includes, for example, an enzyme sensor 10A, a measurement circuit 21, a data processing device 22, a data display device 23, and a standard gas generation device 31, as shown in FIGS. A pressurizing pump 33, a reservoir tank 34, a pressure adjusting device 35, a valve driving device 40C, a pressure gauge 52, a control device 60C, and the like.

<Pressure pump>
The pressurization pump 33, for example, inhales and pressurizes a gas sample such as the external atmosphere or a standard gas generated by the standard gas generation device 31 according to a control signal input from the control device 60C, and supplies the enzyme sensor 10A. Supply to layer L1.
Specifically, the suction side of the pressurizing pump 33 is connected to, for example, a predetermined region (a region where a gas sample such as the external atmosphere exists) and the standard gas generation device 31 via a switching valve 41 with a tube. For example, the exhaust side is connected to a reservoir tank 34 for storing a gas (a gas sample or a standard gas) pressurized by a pressurizing pump 33 via a tube. For example, the pressurizing pump 33 pressurizes the sucked gas and introduces the pressurized gas (pressurized gas) from the gas inlet 831 of the enzyme sensor 10 </ b> A via the reservoir tank 34 and the pressure adjusting device 35. Thus, the gas is supplied to the gas phase chamber (supply layer L1).

<Pressure adjustment device>
For example, the pressure adjustment device 35 adjusts the pressure of the gas supplied to the supply layer L1 of the enzyme sensor 10A according to the control signal input from the control device 60C.
Specifically, the intake side of the pressure adjusting device 35 is connected to, for example, the reservoir tank 34 via a tube, and the exhaust side is connected to, for example, a gas inlet 831 of the enzyme sensor 10A via a tube. ing. For example, the pressure adjusting device 35 adjusts the pressure of the pressurized gas in the reservoir tank 34, introduces the pressurized gas whose pressure has been adjusted from the gas inlet 831 of the enzyme sensor 10 </ b> A, and outputs the gas phase chamber ( The supply layer L1) is supplied.

<Valve drive device>
For example, the valve drive device 40C drives each valve (the switching valve 41, the discharge-side flow rate adjustment valve 43, and the like) included in the concentration measurement system 1000C in accordance with a control signal input from the control device 60C.
Here, the adjusting means for adjusting the pressure applied to the permeable membrane by adjusting the pressure in the supply layer L1 includes, for example, the pressure adjusting device 35, the valve driving device 40C, and the discharge-side flow rate adjusting valve 43.

<Control device>
The control device 60C is a device for controlling each device constituting the concentration measurement system 1000C, for example.
Specifically, the control device 60C includes, for example, a CPU 61, a RAM 62, a storage unit 63C, and the like as shown in FIG.

  For example, the calibration curve creation program 63aC causes the CPU 61 to realize a function of creating a calibration curve used when measuring the concentration of the detection target substance.

  Specifically, for example, the CPU 61 inputs a control signal to the valve driving device 40C and switches the switching valve 41 so that the standard gas generated by the standard gas generating device 31 is supplied to the enzyme sensor 10A. .

  Next, for example, the CPU 61 inputs a control signal to the pressure adjusting device 35 or the valve driving device 40C based on the pressure measured by the pressure gauge 52, and supplies the supply layer L1 with a constant pressure in the supply layer L2. While adjusting the pressure of the standard gas (pressurized gas) and the discharge side flow rate adjustment valve 43, a control signal is input to the standard gas generator 31 and the pressure pump 33 to sequentially generate standard gases having different substrate concentrations. Then, the sensor is sequentially supplied to the enzyme sensor 10A, and a control signal is input to the measurement circuit 21 or the data processing device 22 to create a calibration curve.

The CPU 61 performs this series of processes for each of a plurality of pressures (for example, “pressure Pa”, “pressure Pb”,...), For example. That is, for example, the CPU 61 creates a calibration curve corresponding to each of a plurality of pressures (a calibration curve corresponding to “pressure Pa”, a calibration curve corresponding to “pressure Pb”,...).
The created calibration curve is stored in, for example, the RAM 62 or the storage unit 63C.

  The threshold value determining program 63bC causes the CPU 61 to realize a function of determining a predetermined threshold value used when measuring the concentration of the detection target substance, for example.

  Specifically, for example, the CPU 61 determines a detection density range based on a calibration curve created by the CPU 61 that has executed the calibration curve creation program 63aC, and a response corresponding to one density within the determined detection density range. The current is determined as a predetermined threshold corresponding to the pressure applied to the permeable membrane 400 (that is, a predetermined threshold corresponding to the pressure in the supply layer L1).

More specifically, for example, when a calibration curve as shown in FIG. 6 is created as a calibration curve corresponding to “pressure Pa”, the detected concentration range is determined as C1 to C3, and the determined detected concentration range is determined. The “response current I2” corresponding to one concentration C2 is determined as a threshold corresponding to “pressure Pa”.
In FIG. 6, one concentration C2 is arbitrary as long as it is within the detection concentration range C1 to C3.

For example, the measurement program 63cC causes the CPU 61 to realize a function of measuring the concentration of the detection target substance using the enzyme sensor 10A.
That is, the CPU 61 detects, for example, the detection target substance based on the detection result data regarding the detection result by the enzyme sensor 10A and the pressure applied to the adjusted permeable membrane 400 (that is, the adjusted pressure in the supply layer L1). Measure the concentration.

  Specifically, the CPU 61 inputs a control signal to the valve driving device 40C, for example, and switches the switching valve 41 so that a gas sample such as external air is supplied to the enzyme sensor 10A.

Next, the CPU 61 inputs a control signal to the pressure adjusting device 35 and the valve driving device 40C based on the pressure measured by the pressure gauge 52, for example, so that the pressure applied to the permeable membrane 400 becomes a predetermined magnitude (ie, The control signal is sent to the pressurizing pump 33 while adjusting the pressure of the gas sample (pressurized gas) supplied to the supply layer L1 and the discharge side flow rate adjusting valve 43 so that the pressure in the supply layer L1 becomes a predetermined magnitude. Is input to supply the gas sample to the enzyme sensor 10A.
More specifically, for example, the pressure in the supply layer L1 corresponds to a pressure curve (for example, “pressure Pa”, “pressure Pb”,...) (Corresponding to a calibration curve created by the CPU 61 executing the calibration curve creation program 63aC. Pa <Pb <...)) Is adjusted to be the same as the smallest pressure (“pressure Pa”).

  Next, for example, the CPU 61 inputs a control signal to the measurement circuit 21 and measures response current from the enzyme sensor 10A (response output of the enzyme sensor 10A), thereby acquiring response data regarding the response output of the enzyme sensor 10A. To do.

Next, the CPU 61, for example, has a predetermined value corresponding to the pressure applied to the permeable membrane 400 among predetermined threshold values determined by the CPU 61 that executes the threshold value determination program 63bC, based on the acquired response data (response current value). It is determined whether or not a threshold value (that is, a predetermined threshold value corresponding to the pressure in the supply layer L1) has been exceeded.
More specifically, for example, when a calibration curve as shown in FIG. 6 is created as a calibration curve corresponding to “pressure Pa” and the pressure in the supply layer L1 is adjusted to “pressure Pa”, the acquired response is obtained. It is determined whether or not the value based on the data exceeds a predetermined threshold “response current I2” corresponding to the pressure “pressure Pa” in the supply layer L1.

  And when it is judged that the value based on response data exceeded the predetermined threshold value, CPU61 determines the said response data as detection result data regarding the detection result by 10 A of enzyme sensors, for example.

  Next, for example, the CPU 61 inputs a control signal to the data processing device 22 and corresponds to numerical data based on the response data (that is, a value based on the response data (response current value) and a pressure in the supply layer L1. Data relating to the concentration of the detection target substance calculated from the calibration curve to be generated), a control signal is input to the data display device 23, and numerical information based on the numerical data (that is, the concentration of the detection target substance) is obtained. Display.

On the other hand, when determining that the value based on the response data does not exceed the predetermined threshold, the CPU 61 increases the pressure applied to the permeable membrane 400 (that is, the pressure in the supply layer L1) from the previous time, for example. A series of processing (adjustment-acquisition-determination) is repeated until detection result data regarding the detection result by the enzyme sensor 10A is determined.
More specifically, for example, the pressure in the supply layer L1 corresponds to a pressure curve (for example, “pressure Pa”, “pressure Pb”,...) (Corresponding to the calibration curve created by the CPU 61 executing the calibration curve creation program 63aC. (Pa <Pb <.
The CPU 61 functions as a measurement unit, an adjustment control unit, an acquisition unit, a determination unit, and a determination unit by executing the measurement program 63cC.

<Concentration measurement method>
An example of the concentration measurement method for the detection target substance using the enzyme sensor 10A by the concentration measurement system 1000C is the concentration measurement method for the detection target substance using the enzyme sensor 10A according to the concentration measurement system 1000B of the third embodiment. Since it is substantially the same as (FIG. 21), detailed description is abbreviate | omitted.

  According to the concentration measurement system 1000C in the fourth embodiment described above, the pressure of the gas (pressurized gas) supplied to the supply layer L1 and the flow rate of the gas discharged from the supply layer L1 are adjusted. Since the pressure in the supply layer L1 is adjusted by the above, the pressure in the supply layer L1 can be reliably adjusted with a simple configuration.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof.

  The method of adjusting the pressure applied to the permeable membrane 400 is not limited to that of the first to fourth embodiments. The pressure applied to the permeable membrane 400 is adjusted to adjust the membrane permeability of the detection target substance. It is optional if it can.

In the first embodiment, the enzyme sensor 10 may be provided with a spacer 700 that is disposed between the permeable membrane 400 and the electrode 240 and supports the permeable membrane 400 so that the permeable membrane 400 does not deform.
In the second to fourth embodiments, the enzyme sensor 10A may be provided with a deformation preventing member 500 that is disposed on at least one surface of the permeable membrane 400 and prevents the permeable membrane 400 from being deformed.

In the first to fourth embodiments, the enzyme is contained in the detection layer L2 by using the electrolyte containing the enzyme as the electrolyte introduced into the detection layer L2. The method of inclusion in L2 is not limited to this, and may be a method of directly fixing on the electrodes 240 and 240A (working electrodes 241 and 241A) by a known immobilization method, or a known immobilization. A method may be used in which a predetermined carrier on which an enzyme is immobilized is disposed in the detection layer L1.
Here, when a predetermined carrier on which the enzyme is immobilized is arranged in the detection layer L1, the predetermined carrier on which the enzyme is immobilized may be used as the spacer 700.

  In the examples of the first to fourth embodiments, the gas sample is supplied to the supply layer L2, but the sample supplied to the supply layer L2 is arbitrary as long as it is a fluid sample. You may make it supply.

  In the first to fourth embodiments, the receptor is not limited to an enzyme, and may be any biological substance (a molecular identification element derived from a living body) that selectively reacts with a detection target substance. Specifically, for example, an antibody or a microorganism may be used.

In the first to fourth embodiments, the sensor is a biosensor containing a biocatalyst (receptor) that selectively reacts with the detection target substance in the detection layer L1, but the sensor of the present invention is not necessarily limited to the detection layer. The sensor which does not contain a biocatalyst in L1 may be sufficient.
Specifically, for example, a sensor in which a metal catalyst is contained in the detection layer L1 may be used.
Examples of the sensor in which the detection layer L1 includes a metal catalyst include an electrolyte type sensor (constant potential electrolytic sensor) in which a metal catalyst such as gold or platinum is supported on the electrodes 240 and 240A. The constant potential electrolytic sensor is a sensor that electrolyzes gas on the working electrodes 241 and 241A maintained at a constant potential, and detects the current generated at that time as the gas concentration.

In the first to fourth embodiments, the electrodes 240 and 240A are not limited to those of the embodiment, and are formed from platinum, gold, silver, carbon or the like by a screen printing method, a vapor deposition method, a sputtering method, or the like. It is optional as long as it has been made.
Further, the reference electrodes 243 and 243A which are silver / silver chloride electrodes are formed by temporarily forming a silver electrode by a screen printing method, a vapor deposition method, a sputtering method or the like, and then electrolyzing a constant current in a second silver chloride aqueous solution. Any method may be used as long as it is formed by a dipping method, a method of applying and laminating silver chloride by a screen printing method, or the like.
In addition, the electrodes 240 and 240A have a tripolar structure including the working electrodes 241 and 241A, the counter electrodes 242 and 242A, and the reference electrodes 243 and 243A, but the electrodes 240 and 240 have a bipolar structure in which the reference electrodes 243 and 243A are not provided. (Bipolar structure of working electrodes 241 and 241A and counter electrodes 242 and 242A) may be used.

In the first and second embodiments, the method for measuring the concentration of the substance to be detected using the enzyme sensors 10 and 10A by the concentration measuring systems 1000 and 1000A is not limited to that in the embodiment.
For example, the threshold value (third threshold value) corresponding to the largest flow rate (third flow rate) among the flow rates corresponding to the created calibration curve is also determined, and the value based on the acquired response data is the third threshold value. If the value based on the acquired response data is determined not to exceed the third threshold value, for example, a message indicating a measurement error is displayed on the data display device 23 or the like. Then, an error report may be sent to the user.
Further, for example, the type of the flow rate of the standard gas supplied to the supply layer L1 is not limited to the first flow rate to the third flow rate, and may be any as long as it is plural.
In addition, for example, two threshold values are provided for each flow rate, and a range between the two threshold values is set as an allowable range, and it is determined whether or not a value based on the acquired response data is within the allowable range. You may make it do.

In the third and fourth embodiments, the method for measuring the concentration of the substance to be detected using the enzyme sensor 10A by the concentration measuring systems 1000B and 1000C is not limited to that in the embodiment.
For example, a threshold value (third threshold value) corresponding to the largest pressure (third pressure) among the pressures corresponding to the created calibration curve is also determined, and a value based on the acquired response data is determined as the third threshold value. If the value based on the acquired response data is determined not to exceed the third threshold value, for example, a message indicating a measurement error is displayed on the data display device 23 or the like. Then, an error report may be sent to the user.
Further, for example, the type of pressure in the supply layer L1 is not limited to the first pressure to the third pressure, and may be arbitrary as long as it is plural.
Further, for example, two threshold values are provided for each pressure, and a range between the two threshold values is set as an allowable range, and it is determined whether or not a value based on the acquired response data is within the allowable range. You may make it do.

  In the first to fourth embodiments, when the CPU 61 determines that the value based on the response data does not exceed the predetermined threshold value, for example, the CPU 61 increases the pressure applied to the permeable membrane 400 from the previous time, The processing (adjustment-acquisition-determination) is repeated until the detection result data related to the detection results by the enzyme sensors 10 and 10A is determined. However, the present invention is not limited to this. If the CPU 61 determines that the threshold value has been exceeded, the CPU 61, for example, makes the pressure applied to the permeable membrane 400 smaller than the previous time, and performs a series of processing (adjustment-acquisition-determination) as a detection result regarding the detection results by the enzyme sensors 10, 10A. The process may be repeated until the data is determined, or if the CPU 61 determines that the value based on the response data is outside the predetermined allowable range, the CPU 61 For example, the pressure applied to the permeable membrane 400 is made larger or smaller than the previous time, and a series of processing (adjustment-acquisition-determination) is repeatedly performed until the detection result data regarding the detection results by the enzyme sensors 10, 10A is determined. May be.

  In the first to third embodiments, the intake pump 32 is arranged between the switching valve 41 and the supply-side flow rate adjustment valve 42. However, the present invention is not limited to this. For example, a predetermined region ( The intake pump 32 may be disposed both between the region in which a gas sample such as the external atmosphere exists) and the switching valve 41 and between the standard gas generator 31 and the switching valve 41.

It is a figure which shows the structure of the density | concentration measuring system of 1st Embodiment. It is a figure which shows the functional structure of the density | concentration measuring system of 1st Embodiment. It is a top perspective view of the enzyme sensor with which the concentration measuring system of a 1st embodiment is provided. It is a figure which shows typically the cross section in the IV-IV line of FIG. It is an exploded view of the enzyme sensor with which the concentration measuring system of a 1st embodiment is provided. It is a figure for demonstrating the predetermined threshold value corresponding to the pressure concerning a permeable membrane. It is a flowchart which shows an example of the density | concentration measuring method of the detection target substance using the enzyme sensor by the density | concentration measuring system of 1st Embodiment. It is a front view of the enzyme sensor in the state incorporated in the concentration measurement system of the first embodiment. It is a figure which shows the evaluation result (flow rate dependence of the response current from an enzyme sensor) of the density | concentration measuring system of the Example of 1st Embodiment. It is a figure which shows the evaluation result (creation of a calibration curve) of the density | concentration measuring system of the Example of 1st Embodiment. It is a figure which shows the structure of the density | concentration measuring system of 2nd Embodiment. It is a figure which shows the functional structure of the density | concentration measuring system of 2nd Embodiment. It is a top perspective view of the enzyme sensor with which the concentration measuring system of a 2nd embodiment is provided. It is a figure which shows typically the cross section in the XIV-XIV line | wire in FIG. It is a figure which shows typically the cross section in the XV-XV line | wire in FIG. It is the bottom view (a) of the upper side support body in the state where the permeable membrane was attached, and the top view (b) of the lower side support body in the state where the electrode substrate part was attached. It is a figure which shows the evaluation result (flow rate dependence of the response current from an enzyme sensor) of the density | concentration measuring system of the Example of 2nd Embodiment. It is a figure which shows the evaluation result (creation of a calibration curve) of the density | concentration measuring system of the Example of 2nd Embodiment. It is a figure which shows the structure of the density | concentration measuring system of 3rd Embodiment. It is a figure which shows the functional structure of the density | concentration measuring system of 3rd Embodiment. It is a flowchart which shows an example of the density | concentration measuring method of the detection target substance using the enzyme sensor by the density | concentration measuring system of 3rd Embodiment. It is a figure which shows the structure of the density | concentration measuring system of 4th Embodiment. It is a figure which shows the functional structure of the density | concentration measuring system of 4th Embodiment.

Explanation of symbols

10,10A Enzyme sensor (sensor, biosensor)
35 Pressure adjusting device (adjusting means)
40, 40B, 40C Valve drive (adjustment means)
42 Supply-side flow rate adjustment valve (adjustment means)
43 Discharge-side flow rate adjustment valve (adjustment means)
61 CPU (measurement means, adjustment control means, acquisition means, determination means, determination means)
63c, 63cB, 63cC Measurement program (measurement means, adjustment control means, acquisition means, determination means, determination means)
240, 240A Electrode 400 Permeation membrane 500 Deformation prevention member 700 Spacer 1000, 1000A, 1000B, 1000C Concentration measurement system L1 Supply layer L2 Detection layer

Claims (9)

A supply layer to which a fluid sample containing a detection target substance is supplied; a detection layer disposed adjacent to the supply layer; and the supply layer and the detection layer being spaced apart, and at least the detection target A sensor having a permeable membrane through which a substance passes, and an electrode disposed on the detection layer so as to face the permeable membrane;
Adjusting means for adjusting the pressure applied to the permeable membrane;
Measurement means for measuring the concentration of the detection target substance based on detection result data relating to a detection result by the sensor and pressure applied to the permeable membrane adjusted by the adjustment means;
A concentration measurement system comprising: The concentration measurement system according to claim 1,
The measuring means includes
Adjustment control means for adjusting the adjustment means so that the pressure applied to the permeable membrane has a predetermined magnitude;
Obtaining means for obtaining response data relating to the response output of the sensor;
Determination means for determining whether a value based on the response data acquired by the acquisition means exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane;
A determination unit that determines the response data as the detection result data when the determination unit determines that the value based on the response data exceeds the threshold;
The adjustment control unit causes the adjustment unit to adjust the pressure applied to the permeable membrane to be larger than the previous time when the determination unit determines that the value based on the response data does not exceed the threshold value. Concentration measuring system characterized by that. The concentration measurement system according to claim 1 or 2,
The concentration measuring system is characterized in that the adjusting means adjusts a pressure applied to the permeable membrane by adjusting a flow rate of a fluid sample supplied to the supply layer. In the concentration measurement system according to any one of claims 1 to 3,
The concentration measuring system characterized in that the adjusting means adjusts the pressure applied to the permeable membrane by adjusting the pressure in the supply layer. In the concentration measuring system according to any one of claims 1 to 4,
The sensor is
A concentration measurement system comprising a deformation preventing member disposed on at least one surface of the permeable membrane and preventing deformation of the permeable membrane. In the concentration measurement system according to any one of claims 1 to 5,
The sensor is
A concentration measurement system comprising a spacer that is disposed between the permeable membrane and the electrode and supports the permeable membrane so that the permeable membrane does not deform. A supply layer to which a fluid sample containing a detection target substance is supplied; a detection layer disposed adjacent to the supply layer; and the supply layer and the detection layer being spaced apart, and at least the detection target In the method for measuring a concentration of a substance to be detected using a sensor having a permeable membrane through which a substance permeates and an electrode disposed on the detection layer so as to face the permeable membrane,
An adjustment step for adjusting the pressure applied to the permeable membrane to a predetermined magnitude;
Then, an acquisition step of acquiring response data regarding the response output of the sensor;
Next, a determination step of determining whether a value based on the acquired response data exceeds a predetermined threshold corresponding to the pressure applied to the permeable membrane;
A determination step of determining the response data as detection result data related to a detection result by the sensor when it is determined in the determination step that a value based on the response data exceeds the threshold;
A calculation step of calculating the concentration of the detection target substance based on the determined detection result data and the pressure applied to the permeable membrane adjusted by the adjustment unit;
When it is determined in the determination step that the value based on the response data does not exceed the threshold value, the pressure applied to the permeable membrane is made larger than the previous time, the adjustment step, the acquisition step, and the determination Repeating steps to perform, and
Concentration measuring method characterized by having. A supply layer to which a gas sample containing a detection target substance is supplied, a detection layer that is disposed adjacent to the supply layer and contains a receptor that selectively reacts with the detection target substance, the supply layer, and the supply layer A biosensor that is disposed so as to be separated from the detection layer and has at least a permeable membrane that allows the detection target substance to pass therethrough, and an electrode that is disposed on the detection layer so as to face the permeable membrane;
Adjusting means for adjusting the pressure applied to the permeable membrane by adjusting the flow rate of the gas sample supplied to the supply layer;
Measurement means for measuring the concentration of the detection target substance based on detection result data related to the detection result by the biosensor, and the flow rate of the gas sample adjusted by the adjustment means,
The measuring means includes
Adjustment control means for adjusting the adjustment means so that the flow rate of the gas sample supplied to the supply layer has a predetermined size;
Obtaining means for obtaining response data relating to the response output of the biosensor;
A determination unit that determines whether a value based on the response data acquired by the acquisition unit exceeds a predetermined threshold corresponding to a flow rate of the gas sample supplied to the supply layer;
A determination unit that determines the response data as the detection result data when the determination unit determines that the value based on the response data exceeds the threshold;
The adjustment control means adjusts the adjustment so that when the determination means determines that the value based on the response data does not exceed the threshold, the flow rate of the gas sample supplied to the supply layer is larger than the previous time. A concentration measurement system characterized by having the means adjust. A supply layer to which a gas sample containing a detection target substance is supplied, a detection layer that is disposed adjacent to the supply layer and contains a receptor that selectively reacts with the detection target substance, the supply layer, and the supply layer A biosensor that is disposed so as to be separated from the detection layer and has at least a permeable membrane that allows the detection target substance to pass therethrough, and an electrode that is disposed on the detection layer so as to face the permeable membrane;
Adjusting means for adjusting the pressure applied to the permeable membrane by adjusting the pressure in the supply layer;
Measuring means for measuring the concentration of the substance to be detected based on detection result data relating to the detection result by the biosensor, and the pressure in the supply layer adjusted by the adjusting means,
The measuring means includes
Adjustment control means for adjusting the adjustment means so that the pressure in the supply layer has a predetermined magnitude;
Obtaining means for obtaining response data relating to the response output of the biosensor;
Determining means for determining whether a value based on the response data acquired by the acquiring means exceeds a predetermined threshold corresponding to the pressure in the supply layer;
A determination unit that determines the response data as the detection result data when the determination unit determines that the value based on the response data exceeds the threshold;
The adjustment control unit causes the adjustment unit to adjust the pressure in the supply layer to be larger than the previous time when the determination unit determines that the value based on the response data does not exceed the threshold value. Concentration measuring system characterized by that.

Images