JPH1156389A - Sensor and substance-specifying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sensor capable of detecting continuously an aimed substance and specifying correctly the kind and quantity of the substance by being provided with a membrane interacting with the substance and means for acquiring information on the membrane. SOLUTION: This sensor is applied according to the followings: dissolving a solution containing cyanobacteria and cholesterol into a triton X-100, mounting it on a small hole 103 of a Teflon beaker 102 underwater and leaving as it is, reconstituting a lipid bilayer 104 containing a cell membrane component of cyanobacteria on the small hole 103 of the beaker 102, accommodating the beaker 102 in an outer case 105 and supplying a phosphoric acid buffer solution in the case and beaker to measure a membrane voltage of the lipid bilayer 104, adding a sodium cyanide solution to each buffer solution of the beaker 102 and outer case 105 to measure the membrane voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for detecting the presence of a substance and a substance specifying system equipped with the sensor.

[0002]

2. Description of the Related Art Today, there are many natural products and artificially synthesized substances in the environment.
The number of substances released into the environment is increasing. Among substances in the environment, substances that act on living organisms or cells to inhibit specific functions or cause death of such living organisms or cells (broadly defined poisons), such as tap water and groundwater There are many trihalomethanes, cyanides, cadmium, and dioxins contained in the atmosphere.

[0003] The presence of substances in the environment has been detected, for example, by the following method. In other words, when detecting trihalomethane and cyanide contained in raw water supplied as tap water at a water purification plant, breeding fish such as Mormillus in a water tank that continuously supplies raw water and analyzing the movement of fish by image analysis. By detecting abnormal behavior of fish, the presence of trihalomethane, cyanide, and the like in raw water is detected. Further, after adding a certain amount of ammonia or the like as an assimilating substance of nitrifying bacteria to the raw water, the raw water is brought into contact with an oxygen sensor in which the nitrifying bacteria are immobilized on the electrode surface, and the metabolic activity of the nitrifying bacteria is measured as a dissolved oxygen concentration Estimate from the amount of reduction,
By confirming a decrease in metabolic activity, the presence of trihalomethane, cyanide, and the like in raw water is detected.

[0004]

However, in the method using a living body, there is a problem that although a substance can be detected almost in real time, a substance which does not inhibit the function of the living body cannot be detected at all.

[0005] In many cases, the action of a substance on a living body depends on species and cell specificity. For example, when the substance has no effect on fish or the like, the substance is present despite the presence of the substance. Therefore, there was a problem that the substance could not be detected.

Further, since various substances affect the living body, there is a problem that even when the behavior of a fish or the like is changed, the type and abundance of the substance cannot be specified.

The present invention has been made in view of the above conventional example, and has as its object to provide a sensor capable of continuously detecting a substance and accurately specifying the type and amount of the substance. I do.

[0008] In addition to continuously detecting substances,
It is an object of the present invention to provide a substance specifying system capable of accurately specifying the type and amount of the substance.

[0009]

The sensor according to the present invention comprises:
It is characterized by comprising a film interacting with a substance and a means for acquiring information on the film.

[0010] According to the sensor of the present invention, by acquiring information on a film that interacts with a substance, it is possible to observe a change in the film caused by the interaction with the substance. The type and amount of the substance can be accurately specified.

Further, the substance specifying system according to the present invention comprises:
A sensor comprising: a first film exhibiting a first interaction with a substance; a second film exhibiting a second interaction with the substance; and means for acquiring information on the first and second films. , Means for evaluating the obtained information.

According to the substance identification system of the present invention,
First and second showing first and second interactions with a substance
By acquiring the information of the film and evaluating the acquired information, changes in the first and second films caused by the interaction with the substance can be observed and examined from multiple angles, so that the presence of the substance is detected. At the same time, it becomes possible to accurately specify the type and amount of the substance.

First, the concept of the present invention will be described in detail.

A substance that has some action on a living body is, in other words, a substance that has some action on "cells" constituting the living body. Therefore, it is considered that a substance having any action on a cell shows some interaction with a “cell membrane” provided in the cell. Here, the interaction is
It indicates that the membrane and the substance have some effect on each other, meaning a mechanism that causes the phenomenon such as adhesion and adsorption of the substance to the membrane, uptake of the substance into the membrane, and permeation of the substance through the membrane. I have. Therefore, an artificially prepared membrane (artificial membrane) is attached to, for example, the surface of an electrode, and information on the membrane is obtained through the electrode, thereby detecting the presence of a substance that interacts with the membrane in real time. It becomes possible. That is, information on the membrane that changes due to interaction with the substance, for example, membrane potential, electric capacity, ion permeability,
Light emission, heat generation, heat absorption, and the like are acquired, and the presence of the substance can be determined from the difference between the output values before and after the interaction with the substance. Also, regarding the determination of the type and amount of the substance, for example,
It can be determined as follows.

In general, cell membranes contain molecules such as proteins and sugars in a lipid bilayer composed mainly of phospholipids.
It is configured such that a part of molecules such as proteins and sugars protrude from the surface. Therefore, the membrane of the present invention can be artificially produced, for example, by imitating a cell membrane and blending various kinds of molecules such as proteins or sugars acting on a substance with a lipid membrane or another polymer membrane. . It should be noted that depending on the type of the substance, the substance may interact with the lipid membrane, so that it is not an essential condition to mix the substance and the substance that acts.
It is also possible to use a hollow fiber membrane made of a polymer. Then, when forming the membrane, by changing and combining the types and amounts of lipids, proteins, sugars, and the like, and the method of forming the membrane, it is possible to obtain a sensor that can determine the presence or amount of any substance. . At this time, if information on the membrane obtained when interacting with the substance, for example, how the potential of the membrane changes according to the type and amount of the substance is obtained in advance, it is actually obtained from the membrane. Based on the information, the type and amount of the substance can be easily determined.

Next, the sensor of the present invention will be described in detail.

In the present invention, the film constituting the sensor is:
As described above, a membrane imitating a cell membrane having lipids, proteins and sugars, a membrane composed only of lipids, a hollow fiber membrane made of a polymer, and the like can be given. Membranes that mimic cell membranes and membranes that consist solely of lipids are (1)
Monolayers, (2) planar bilayers, (3) liposomes or vesicles can be classified. In the present invention, any type of membrane can be used. FIG. 12 is a diagram conceptually showing an example of a membrane that mimics a cell membrane. In a liquid phospholipid bilayer 120, spherical membrane proteins 121 are embedded in various forms. It is possible to move freely in the double membrane 120. By the way, the lipid bilayer membrane is composed of an enormous number of lipid molecules,
There, statistical thermodynamic phenomena are observed. That is,
Lipid bilayers show a phase transition due to temperature changes, for example,
Dipalmitoyl phosphatidylcholine changes from a crystalline phase at low temperature to a gel phase, a ripple phase, and a fluid phase, and the physical properties of the lipid bilayer greatly change with this phase transition. For example, the diffusion constant of a lipid molecule or a protein molecule is increased by several tens, sometimes several hundreds, according to the phase transition. Therefore, in the present invention, it is important to grasp the phase transition point of the lipid bilayer membrane used and to grasp the temperature at the time of measurement when detecting a substance. In membranes that mimic cell membranes, the main components of the membrane are proteins and lipids, and glycoproteins and glycolipids can be introduced. At this time, the relative ratio of protein to lipid can be arbitrarily controlled, but generally, the protein is 20% -8% by dry weight.
Control within the range of 0%. In addition, a membrane protein is a substance that generally shows biochemical activity, and is a substance that shows an interaction with a specific substance in each membrane system. The membrane protein is deformed depending on the thickness of the membrane lipid because the hydrophobic region interacts with the hydrophobic fatty acid side chain of the membrane lipid, and this deformation fluctuates the activity of the membrane protein. Therefore, it is desirable to select a membrane lipid molecular species optimal for the activity. Further, the membrane protein binds to the lipid bilayer by non-covalent bonds such as hydrophobic bonds and electrostatic interactions.
Here, the binding method between the membrane protein and the lipid bilayer membrane can be, for example, a mode schematically shown in FIG. 13, and the portion of the membrane protein 130 embedded in the lipid bilayer membrane 131 is: It is presumed that it has an α-helix structure. The membrane protein can be appropriately selected in accordance with the substance to be detected, and includes various antibodies, antigens, various receptors and enzymes that bind to ligands, and the like.

Further, lipids also have a function of forming a bilayer membrane and binding proteins, such as phospholipids, lysophospholipids, glycosyldiacylglycerol,
Examples include plasmalogen, sphingomyelin and sterol, and examples of glycolipids include sphingolipid, glyceroglycolipid, and glycosphingolipid. When using a hollow fiber membrane,
Although the size of the pore size can be selected according to the substance to be detected, it is generally desirable that the size be controlled in the range of 0.1 to 5.0 μm. Examples of the polymer used for forming the hollow fiber membrane include, for example, polysulfone, polyether sulfone, polyacrylonitrile, cellulose acetate, polyamide, and polyvinylidene fluoride. A membrane that mimics a biological membrane can also be placed. Further, the protein can be immobilized on a hollow fiber membrane. The hollow fiber membrane can be manufactured using, for example, a heat-induced phase separation method, an evaporation-induced phase separation method, and a diffusion-induced phase separation method.
Furthermore, as a method for producing a membrane mimicking a cell membrane,
For example, an aqueous solution containing an appropriate amount of a protein or glycolipid exhibiting an action with an appropriate lipid and substance, and an appropriate amount of an appropriate surfactant is prepared depending on the application, and the aqueous solution is fixed in a buffer solution using a small syringe. The amount is injected into a Teflon membrane (having a hole with a diameter of about 1 mm in the center). Then, the lipid bilayer membrane is reconstituted in the pores of the Teflon membrane, and at the same time, proteins and glycolipids, etc., which exhibit substances and actions, are taken into the lipid bilayer membrane to form a membrane. Further, a chloroform solution of a protein or glycolipid exhibiting the action of the above lipids and substances is spread on the surface of the buffer, and the membrane is reconstituted on a carrier surface such as an electrode as a lipid monolayer using an LB membrane forming apparatus. Is also possible. Further, the chloroform solution is accommodated in a glass flask, and the solvent is spun in the flask (evaporation) to form a lipid film on the inner wall of the flask. Then, by vigorously stirring or irradiating ultrasonic waves, a lipid membrane called a liposome can be formed. Further, when the suspension of the liposome is passed through a membrane filter having an appropriate pore size, molecules such as lipids are packed in the pores in the membrane filter, so that the membrane filter can be used as a membrane.

In the present invention, the substance is not particularly limited as long as it exhibits the above-mentioned interaction with the membrane. Examples of the substance include staphylococcal α-toxin, vibrio parahaemolyticus toxin, and welsh which directly act on the membrane. Biotoxins such as fungal α and θ toxins, snake venom and bee venom, trichloroethylene (TC
E), organochlorine compounds such as polyvinyl chloride (PVC), PCB and dioxin, various antibodies and antigens, various ligands binding to receptors, potassium, lithium,
A wide range can be mentioned, including ions such as calcium and sodium and virus particles themselves which fuse with membranes. In detecting these substances, as described above, there are many mechanisms of action, from those with large specificities such as antigen-antibody reactions to those that show action with almost all lipid bilayers. Therefore, it is necessary to adapt the configuration of the membrane to the substance to be detected.

The information on the film includes a film potential, a film surface potential, electric capacity, conductivity, resistivity, light generated from the film and fluidity of the film. The reason why the presence of a substance can be detected by acquiring such information will be described below with reference to an example. FIG. 14 is a diagram showing the shape of a free energy barrier for polar and non-polar solutes passing through a lipid bilayer membrane. In order for a substance to pass through the lipid bilayer 141, (1) it enters the membrane against the interface resistance or free energy barrier, and (2) the lipid bilayer 1
41, and (3) must exit again on the opposite side of the lipid bilayer 141, against any resistance at the interface. At this time, the configuration of the lipid bilayer membrane is greatly disturbed, and the information of the membrane changes greatly. Therefore, the presence of a substance can be detected by monitoring the information of the membrane. Interactions with substances can also form permeation holes in the membrane, for example, a single peptide, colicin, forms a non-selective channel with a voltage-sensitive gate in the membrane . Therefore, the presence of a substance such as colicin can be detected by monitoring the information on the film. The means for acquiring the film information is not particularly limited as long as it has a configuration capable of extracting the information from the film. For example, when measuring the membrane potential, a method of arranging electrodes through a membrane, a method of using a spin-labeled EPR probe, and a method of using an optical probe such as a merocyanine, oxonol, or cyanine dye were applied. Various devices can be mentioned, and when measuring the fluidity of the membrane, various methods using a method of quantifying the fluidity of the membrane by a parameter derived from the spectroscopic properties of the fluorescent probe and the spin probe are used. Devices.

Next, the substance specifying system according to the present invention will be described in detail. In general, information obtained from a film by interaction with a substance slightly differs depending on the type and abundance of the substance when the composition of the film is the same. Therefore,
For each of the various substances, and for the case where those substances are combined, information obtained by interaction with a film having a certain configuration is collected in advance, and the actually obtained information and the previously collected information are collected. If you compare
The presence and amount of the substance can be easily detected. In addition, information obtained from a film by interaction with a substance has the same combination and abundance of a substance or a plurality of substances, and even information of the same type slightly differs depending on the structure of the film. . Therefore, information obtained by the interaction with each film when the abundance ratio and abundance of each material are changed for each of various types of materials and combinations of those materials for a plurality of types of films. Is collected in advance, and the information obtained from a plurality of types of films and the information collected in advance are evaluated and evaluated, whereby the presence and amount of the substance can be easily detected. In this case, since a plurality of types of sensors are used, the accuracy of detection and quantification of the substance is further improved. FIG. 15 shows a sensor 151 that differs only in the film configuration.
It is a figure showing information (here, membrane potential) acquired from membranes 152a-152c when substance A and substance B are detected using a-151c. As shown in FIG. 15, if the substance is different, the information obtained is different even when the same sensor is used. In addition, even if the same substance is used, the information to be obtained is different if the amount is different. Therefore, if such information is collected in advance, the presence and amount of the substance can be detected with high accuracy. In addition, when a substance is detected only using a highly specific reaction such as an antigen-antibody reaction or an enzyme reaction, the presence of the substance can be easily confirmed from the acquired information. It is only necessary to collect information about in advance. Note that the film may be configured to interact with only one substance,
It may be configured to show an interaction with a plurality of substances. Further, as a method of evaluating the obtained information, for example, the waveforms (patterns) of the respective information shown in FIG. 15 are compared, or a database of the waveforms (patterns) of the respective information created in advance is referred to. The presence and abundance of the substance may be determined in this way, or the presence and abundance of the substance may be determined by comparing only the peaks of each information. If it is, it can be used as a means for evaluating the obtained information. Further, the information may be processed by synthesizing each information, and the presence and the amount of the substance may be detected based on the processed information.

The sensor and the substance specifying system according to the present invention can be used for any applications such as clinical tests such as blood tests, measurement of freshness of food, detection of substances existing in the environment such as groundwater, rivers and oceans. Although it can be applied, it is possible to arrange a sensor in a living body, for example, to detect a blood glucose level, or to arrange a sensor in the environment, for example, to detect a mutagen such as dioxin, in real time. When information is obtained from the membrane by using the method described above, if the information is transmitted from the original position where the sensor is arranged and the transmitted information is received at a specific place, there is a restriction on the arrangement of the sensor. Without detecting a substance, it is possible to continuously specify the type and amount of the substance. Further, the sensor and the substance specifying system according to the present invention can acquire information from the membrane in almost real time by observing a change from the steady state of the membrane, but do not apply a living organism (living body). Therefore, it goes without saying that there is no need to administer any anabolic substance for maintaining the homeostasis of the organism or maintain the surrounding environment constantly.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Example 1) First, a cell membrane fraction was prepared from cyanobacteria by zonal centrifugation and isopycnic centrifugation, and the weight ratio of the cell membrane fraction was 30%.
A first solution was prepared by adding% cholesterol.
Next, 1 mL of the first solution was added to 4% of 1% Triton X-100.
1 mL to prepare a second solution, and as shown in FIG.
The pores 10 of the Teflon beaker 102 in water using
3 and left for 1 hour at room temperature, the lipid bilayer membrane 104 containing the cell membrane components of cyanobacteria was reconstituted in the pores 103 of the Teflon beaker 102. Next, as shown in FIG. 1B, the Teflon beaker 102
Is stored in an external container 105, and a 10 mM phosphate buffer solution (pH 6.8) is supplied into each container so that the membrane potential of the lipid bilayer membrane 104 can be measured. Was measured. Next, Teflon beaker 10
2 or 100 μL of a 1 mM sodium cyanide solution was added to the buffer solution contained in the external container 105 (the sodium cyanide solution was finally diluted about 500-fold), and the membrane potential was measured. As a result, the membrane potential changed as shown in FIG. 2A and became constant around 5 mV. Next, the Teflon beaker 102 or the external container 105
Again in the buffer containing the sodium cyanide solution contained in
When L was added, the membrane potential of the lipid bilayer membrane 104 changed again and became constant at around 10 mV, as shown in FIG. 2 (b). On the other hand, instead of the sodium cyanide solution, a 1 mM sodium chloride solution
When L was added, almost no change in the membrane potential was observed as shown in FIG.

Therefore, in this example, it was shown that it is possible in principle to specifically detect cyanide ions. Instead of the lipid bilayer membrane 104, a lipid bilayer membrane (a membrane composed of phosphatidylcholine and cholesterol) containing no cell membrane components of cyanobacteria
In the case where is used, almost no change in the membrane potential was observed regardless of the concentration of cyan ion, and almost constant membrane potential was observed. Was confirmed.

(Example 2) Trichloroethylene (TCE) was detected using the same configuration as in Example 1.
That is, instead of the sodium cyanide aqueous solution, a 10 ppm TCE solution is added to the buffer solution contained in the Teflon beaker 102 or the external container 105 while changing the amount of the TCE added, and the membrane of the lipid bilayer membrane 104 is formed. The change in potential was measured. As a result, the membrane potential of the lipid bilayer 104 becomes
Despite containing the cell membrane components of cyanobacteria, as shown in FIG. 3 (a), it changed to increase with an increase in the amount of TCE added. When a lipid bilayer containing no cell membrane component of cyanobacteria (a membrane composed of phosphatidylcholine and cholesterol) is used instead of the lipid bilayer 104, the change in the membrane potential is represented by ( As shown in b), the change was larger than the change in the membrane potential in the lipid bilayer membrane 104.

Therefore, in a sensor having the same configuration, when the kind of the substance is different, the interaction between the substance and the film is different, and it is confirmed that the obtained information is also different. .

(Embodiment 3) With the same configuration as in Embodiment 1, a 10 mM aqueous solution of sodium cyanide and a 10 ppm TCE solution are sequentially added to a buffer contained in the Teflon beaker 102 or the external container 105 ( Finally, each was diluted 500 times), lipid bilayer 1
The change in the membrane potential of No. 04 was measured. As a result, as shown in FIG. 4, it was confirmed that the membrane potential of the lipid bilayer membrane 104 changed so as to correspond to each substance. Further, a mixed solution obtained by previously mixing a 10 mM aqueous solution of sodium cyanide and a 10 ppm TCE solution in a buffer solution contained in the Teflon beaker 102 or the external container 105 is added, and the change in the membrane potential of the lipid bilayer membrane 104 is measured. As a result of the measurement, it was confirmed that the membrane potential of the lipid bilayer membrane 104 showed a change obtained by adding the change corresponding to each substance, as shown by the solid line in FIG.

Accordingly, it was confirmed that the lipid bilayer membrane 104 independently interacts with both sodium cyanide and TCE.

(Embodiment 4) With exactly the same configuration as in Embodiment 1, ground water containing TCE is added to the buffer solution stored in the Teflon beaker 102 or the external container 105 (finally, 10 times). Diluted), lipid bilayer membrane 104
The change in membrane potential was measured. As a result, when the result of detection of TCE in the same groundwater by gas chromatography was associated with the change in the membrane potential of the lipid bilayer 104,
It was confirmed that the change in the membrane potential of the lipid bilayer membrane 104 was very highly consistent with the results of gas chromatography. As shown in FIG. 6, it was confirmed that the sensor according to the present example continued to operate stably for at least six months after the start of measurement.

Example 5 First, a cell membrane fraction was prepared from cyanobacteria by zonal centrifugation and isopycnic centrifugation, and the weight ratio of the cell membrane fraction to the cell membrane fraction was 30%.
A first solution was prepared by adding% cholesterol.
Next, 1 mL of the first solution was added to 4% of 1% Triton X-100.
Dissolved in mL and introduced dipalpytoyl phosphatidylethanolamine (DTP-D
(PPE) was added so as to contain 5 mol% in the membrane to prepare a third solution. As shown in FIG.
About 0 μL of the lipid duplex containing the cell membrane component of cyanobacteria containing 5 mol% of DTP-DPPE was gently placed in the pore 103 provided in the Teflon beaker 102 in water using a syringe 101 and left at room temperature for 1 hour. The membrane was reconstituted in the pores 103 of the Teflon beaker 102. Next, a monoclonal antibody against dioxin is cross-linked (SPDP)
On the surface of the lipid bilayer membrane. On the other hand, normal air (1 Nm ³ , containing 1 ng of dioxins) was added to 10 atmospheres.
After circulating through a column containing mL of water for 1 hour, 1 mL of the water was added to the buffer stored in the Teflon beaker 102 or the external container 105 in the same manner as in Example 1. As a result, a change in membrane potential of 0.1 mV was observed in the lipid bilayer membrane. The water obtained from the column circulating the atmosphere containing no dioxins is also supplied to the Teflon beaker 102 or the external container 1 similarly.
When the lipid bilayer was added to the buffer solution contained in the buffer membrane 05, the membrane potential of the lipid bilayer membrane hardly changed.

Therefore, it was confirmed that the lipid bilayer specifically interacts with dioxin only and changes the membrane potential only when dioxin is present.

Example 6 First, a concentrated solution of lipid A was prepared, and about 50 μL of the concentrated solution was provided in a Teflon beaker 102 in water using a syringe 101 as shown in FIG. The lipid bilayer composed of lipid A was formed in the pores 103 of the Teflon beaker 102 by gently placing it on the pores 103 and leaving it at room temperature for 1 hour. Next, as shown in FIG. 1B, the Teflon beaker 102
Is stored in an external container 105, and a 10 mM phosphate buffer solution (pH 6.8) is supplied into each container so that the membrane potential of the lipid bilayer membrane can be measured. Was measured. Next, Teflon beaker 102
Alternatively, Salmonella endotoxin was added to the buffer contained in the external container 105 so as to have the concentration shown on the horizontal axis of the graph in FIG. 7, and the membrane potential was measured. As a result, as shown in FIG. 7, it was confirmed that the membrane potential increased in proportion to the concentration of Salmonella endotoxin. Therefore, it is possible to not only detect the presence of Salmonella endotoxin, but also quantify the concentration of Salmonella endotoxin based on the change in the membrane potential of the lipid bilayer.

Example 7 A concentrated solution was prepared by mixing sphingomyelin, cholesterol and phospholipid at a ratio of 5:50:45 (mol%), and the pores of the Teflon beaker 102 were prepared in the same manner as in Example 6. Next, a lipid bilayer membrane was constructed. Next, as shown in FIG. 1B, the Teflon beaker 102 is housed in the external container 105, and a 10 mM HEPES buffer solution (pH 7.
4) was supplied, the membrane potential of the lipid bilayer membrane was measured, and the membrane potential was measured. Next, diphtheria toxin was added to the buffer solution contained in the Teflon beaker 102 or the external container 105 so as to have the concentration shown on the horizontal axis of the graph in FIG. 8, and the membrane potential was measured. As a result, as shown in FIG. 7, it was confirmed that the membrane potential increased in proportion to the concentration of diphtheria toxin. Therefore, it is possible to not only detect the presence of diphtheria toxin but also quantify the concentration of diphtheria toxin based on the change in the membrane potential of the lipid bilayer.

(Examples 8 and 9) A concentrated solution of dimistoy phosphatidylcholine was prepared, and a lipid bilayer membrane was formed in the pores of the Teflon beaker 102 in the same manner as in Example 6. Next, as shown in FIG. 1 (b), the Teflon beaker 102 is housed in the external container 105, and a 10 mM HEPES buffer solution (pH 7.4) is placed in each container.
Was supplied, and the membrane potential of the lipid bilayer membrane was measured, and the membrane potential was measured. Next, 1 ppm of cis-DCE (Example 8) and 10% of TCE were added to the buffer contained in the Teflon beaker 102 or the external container 105.
ppm (Example 9), and the membrane potential of the lipid bilayer was measured. As a result, as shown in FIG. 9, the membrane potential shows different changes between the case of cis-DCE and the case of TCE, thus confirming that cis-DCE and TCE can be respectively detected.

(Examples 10-14) Lecithin, cholesterol and dipalmitoylphosphatidylethanolamine were added in a ratio of 50: 45: 5 (Example 10) and 50:45:
3 (Example 11), 50: 45: 2 (Example 12), 5
A concentrated solution was prepared so as to have a ratio of 0: 45: 1 (Example 13) and a ratio of 50: 45: 0 (Example 14) (all mol%), and the Teflon beaker 102 was prepared in the same manner as in Example 6. A lipid bilayer membrane was formed in each pore. next,
As shown in FIG. 1B, the Teflon beaker 102 is housed in an external container 105, and a 10 mM HEPES buffer solution (pH 7.4) is supplied into each container.
The membrane potential of each of the above lipid bilayer membranes was measured and the membrane potential was measured. Next, TCE was added to the buffer solution contained in the Teflon beaker 102 or the external container 105 so that the TCE became 10 ppm, and the membrane potential of the lipid bilayer membrane was measured. As a result, as shown in FIG. 10, the membrane potential changes differently depending on the structure of the membrane. Therefore, by detecting a substance using a plurality of kinds of membranes, it is possible to more accurately specify the substance type and abundance. It was confirmed that it was possible.

Example 15 First, a cell membrane fraction was prepared from macrophages collected from blood using zone centrifugation and isopycnic centrifugation, and 30% by weight of cholesterol was added to the cell membrane fraction. A fourth solution was prepared by addition. Next, a fifth solution was prepared by dissolving 1 mL of the fourth solution in 4 mL of 1% Triton X-100,
As shown in FIG. 1A, about 50 μL of the fifth solution was used in a Teflon beaker 102 in water using a syringe 101.
The lipid bilayer containing the cell membrane components of the macrophages was reconstituted in the pores 103 of the Teflon beaker 102 by gently placing them on the pores 103 provided for the above and left at room temperature for 1 hour. Next, as shown in FIG.
2 in an external container 105, and 10 mM phosphate buffer (pH 7.4) was supplied into each container,
The membrane potential of the lipid bilayer membrane 110 was measured, and the membrane potential was measured. Next, Teflon beaker 1
02 or the buffer solution contained in the external container 105
-1 mixed solution was added (10 ⁴ pfu) 100 [mu] L (the solution was diluted to final approximately 500-fold) to measure the membrane potential. In the present embodiment, the measured membrane potential is transmitted to the transmission unit 111 as a detection signal, and the transmission signal is transmitted through the antenna 112. In addition, the transmitted transmission signal is configured to be received by the antenna 113 and sent to the reception unit 114, demodulated into a detection signal by the reception unit 114, and extracted from the detection terminal 115. The detection terminal 115 may hold a database or the like for evaluating information obtained from the sensor, and may evaluate the obtained information.

As a result of measuring the membrane potential, a change in the membrane potential of 0.1 mV, which is presumed to be caused by the fusion of the virus particles to the membrane, was observed in the lipid bilayer membrane 110. Also, HI
When TMV was used instead of V-1, the membrane potential of lipid bilayer membrane 110 hardly changed. Therefore, it was confirmed that the lipid bilayer membrane can be used for HIV-1 detection, and that information obtained from the membrane is output from the detection terminal in real time.

[0039]

As described above in detail, according to the sensor according to the present invention, a change in a film caused by an interaction with a substance can be observed by acquiring information on a film interacting with the substance. Therefore, it is possible to provide a sensor capable of detecting the presence of a substance and accurately specifying the type and amount of the substance.

Further, according to the substance identification system of the present invention, information of the first and second films showing the first and second interactions with the substance is obtained, and the obtained information is evaluated. First and second resulting from interaction with a substance
Since the change of the film can be observed and examined from various aspects, it is possible to provide a substance specifying system capable of detecting the presence of a substance and accurately specifying the type and amount of the substance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method of forming a film and a configuration of a sensor.

FIG. 2 is a diagram showing measurement results of a membrane potential.

FIG. 3 is a diagram showing measurement results of a membrane potential.

FIG. 4 is a diagram showing a measurement result of a membrane potential.

FIG. 5 is a diagram showing measurement results of a membrane potential.

FIG. 6 is a diagram showing the measurement results of the membrane potential over time.

FIG. 7 is a diagram showing measurement results of a membrane potential.

FIG. 8 is a diagram showing measurement results of a membrane potential.

FIG. 9 is a diagram showing measurement results of a membrane potential.

FIG. 10 is a diagram showing a measurement result of a membrane potential.

FIG. 11 is a diagram showing a configuration of a sensor.

FIG. 12 is a diagram conceptually showing an example of a membrane mimicking a cell membrane.

FIG. 13 is a diagram showing a binding system between a membrane protein and a lipid bilayer membrane.

FIG. 14 is a diagram showing the shape of a barrier of free energy for polar and non-polar solutes passing through a lipid bilayer membrane.

FIG. 15 is a waveform (pattern) of each information obtained from the film.
FIG.

[Explanation of symbols]

101: syringe 102: Teflon beaker 103: pore 104: lipid bilayer membrane 105:
… Outer container 110… lipid bilayer 111… transmitter 11
2, 113 antenna 114 reception unit 115 detection terminal 120 phospholipid bilayer membrane 121, 130 membrane protein 131, 141 lipid bilayer membrane 151a-151c sensor 152a-152c …film

Claims (2)

[Claims] 1. A sensor comprising: a film interacting with a substance; and means for acquiring information on the film. 2. A means for acquiring information of a first film exhibiting a first interaction with a substance, a second film exhibiting a second interaction with the substance, and information of the first and second films. And a means for evaluating the acquired information.