Biosensor and method for regenerating recognition molecule

Abstract

This biosensor (1) comprises: a flow path (2) through which a sample solution (120) containing biomarkers (110) flows; a sensor unit (3) that is disposed in the flow path (2) and has recognition molecules (32); a first electrode (4) and a second electrode (5) that are disposed so as to be separated from each other in the flow path (2); a current application means (6) for applying a current to the first electrode (4) and the second electrode (5); and a detection means (7) for detecting the biomarkers (110) captured by the recognition molecules (32).

Description

Biosensor, method for regenerating recognition molecules

[0001] The present invention relates to a biosensor and a method for regenerating a recognition molecule in a biosensor. This application claims priority to Japanese Patent Application No. 2023-201854, filed on November 29, 2023, the contents of which are incorporated herein by reference.

[0002] Development of wearable devices, such as smartwatches with built-in biosensors, is underway to realize advanced preventive medicine. A biosensor is a sensor that uses a recognition molecule (e.g., an antibody, enzyme, or aptamer) that specifically binds to a specific biomarker. A biosensor detects specific proteins in blood or other samples through the intermolecular interaction between the biomarker and the recognition molecule. In a biosensor, a first recognition molecule is immobilized on a substrate in advance. A sample, such as a liquid containing the biomarker, is then passed through the substrate, capturing the biomarker with the first recognition molecule. A second recognition molecule modified with a labeling substance is then bound to the biomarker, sandwiching the biomarker between the first and second recognition molecules. In this state, the specific biomarker in the sample is quantified by measuring the absorbance, fluorescence intensity, and mass change of the second recognition molecule (label), as well as the absorbance and redox current of the reaction product of the labeling substance (enzyme) and the substrate.

[0003] Examples of biomarkers detected by a wearable device with a built-in biosensor include lifestyle-related disease markers. Examples of tumor markers that suggest the presence of cancer include CEA and AFP (alpha-fetoprotein). Examples of biomarkers that suggest heart disease include oxidized LDL and C-reactive protein (CRP). Examples of biomarkers that suggest dementia include amyloid beta.

[0004] In Japan, which has become a super-aging society, the symptomatic medical system is reaching its limits. Therefore, there is a need to build a society of healthy longevity, prevent lifestyle-related diseases, and move away from symptomatic medical care. Wearable devices with built-in biosensors that can manage the user's (wearer's) health on a daily basis are thought to be an effective means of solving these issues.

[0005] Representative biosensors include, for example, sensors using ELISA (a method for quantifying trace amounts of biological substances using an antigen-antibody reaction), sensors using immunochromatography such as pregnancy test drugs, sensors using surface plasmon resonance (SPR) (see, for example, Non-Patent Document 1), and sensors using enzymes and aptamers.

[0006] Mazher-Iqbal Mohammed, Marc P. Y. Desmulliez, “Lab-on-a-chip based immunosensor principles and technologies for the detection of cardioac. biomarkers: a review”, Lab on a chip 2011, 11, 569-595.

[0007] Conventional biosensors are essentially disposable and cannot be used continuously. This is because, after detecting a biomarker, in order to dissociate the biomarker from the recognition molecule and regenerate the biosensor, it is necessary to use a liquid pump or valve to deliver a regenerating solution (such as an acid or alkali) into the biosensor. This method of dissociating the biomarker not only increases the complexity and size of the biosensor, but also results in the consumption of reagents (necessitating replacement). In other words, conventional regeneration methods hinder the miniaturization of biosensors.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a biosensor that can be used repeatedly and continuously and can be further miniaturized, and a method for regenerating recognition molecules in a biosensor.

[0009] The present invention has the following aspects. [1] A biosensor comprising: a flow path for flowing a sample solution containing a biomarker; a sensor unit disposed within the flow path and having a recognition molecule; first and second electrodes disposed spaced apart within the flow path; a current application unit for applying a current to the first and second electrodes; and a detection unit for detecting the biomarker captured by the recognition molecule. [2] The biosensor according to [1], further comprising a pH detection unit for detecting the pH of the sample solution present in a region including the first electrode and its periphery. [3] A method for regenerating a recognition molecule in the biosensor according to [1] or [2], comprising applying a current to the first and second electrodes by the current application unit to control the pH of the sample solution present in a region including the first electrode and its periphery. [4] The method for regenerating a recognition molecule according to [3], wherein an antibody is used as the recognition molecule. [5] The method for regenerating a recognition molecule according to [3] or [4], wherein the pH of the sample solution present in a region including the first electrode and its periphery is controlled to be between 1 and 3.5. [6] The method for regenerating a recognition molecule according to [3] or [4], wherein the pH of the sample solution present in the region including the first electrode and its periphery is controlled to 10 or higher.

[0010] According to the present invention, it is possible to provide a biosensor that can be used repeatedly and continuously and can be further miniaturized, and a method for regenerating a recognition molecule in a biosensor.

[0011] 1 is a schematic diagram showing the general configuration of a biosensor according to an embodiment of the present invention, illustrating a cross section of the biosensor along the height direction, and is a diagram showing the relationship between applied current and pH of a sample solution in an example.

[0012] The following describes an embodiment of the biosensor and the method for regenerating a recognition molecule in the biosensor of the present invention. Note that this embodiment is specifically described to provide a better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

[0013] [Biosensor] Fig. 1 is a schematic diagram showing the overall configuration of a biosensor according to one embodiment of the present invention, illustrating a cross section of the biosensor along the height direction. As shown in Fig. 1, the biosensor 1 of this embodiment includes a flow path 2, a sensor unit 3, a first electrode 4, a second electrode 5, a current application means 6, and a detection means 7. The biosensor 1 of this embodiment may also include a pH detection unit 8. The sensor unit 3 includes a substrate 31 and a recognition molecule 32 immobilized on a surface 31a of the substrate 31. The sensor unit 3 may also be composed solely of the recognition molecule 32 immobilized on the inner surface 2a of the flow path 2. The biosensor 1 of this embodiment may also include a substrate 9 supporting the flow path 2.

[0014] The flow channel 2 is a flow channel through which a sample solution 120 containing a biomarker 110 flows.

[0015] The first electrode 4 and the second electrode 5 are arranged spaced apart from each other within the flow path 2. For example, as shown in FIG. 1 , the first electrode 4 and the second electrode 5 are arranged within the flow path 2 along the direction in which the sample solution 120 flows (the length direction of the flow path 2) so as to sandwich the sensor unit 3. Alternatively, the first electrode 4 and the second electrode 5 may be arranged within the flow path 2 along a direction perpendicular to the direction in which the sample solution 120 flows (the inner circumferential direction of the flow path 2) so as to sandwich the sensor unit 3. Alternatively, the substrate 31 of the sensor unit 3 may be the first electrode 4. There is almost no difference in the regeneration ability of the recognition molecule 32 by the biosensor 1 between the case in which the first electrode 4 and the second electrode 5 are arranged so as to sandwich the sensor unit 3 and the case in which the substrate 31 of the sensor unit 3 is the first electrode 4.

[0016] The current application means 6 is connected to the first electrode 4 and the second electrode 5, and applies a current to these two electrodes with the first electrode 4 as the anode, oxidizing chloride ions and hydroxide ions in the sample solution 120 on the surface 4a of the first electrode 4, generating chlorine and oxygen, and generating high-concentration hydrogen ions (H ＋ ) region is generated, or a current is applied using the first electrode 4 as a cathode, reducing the hydrogen ions in the sample solution 120 on the surface 4 a of the first electrode 4, generating hydrogen, and forming a high concentration of hydroxide ions (OH －) area is generated.

[0017] The detection means 7 detects the biomarker 110 captured by the recognition molecule 32 .

[0018] The pH detection unit 8 detects the pH of the sample solution 120 present in a region a including the first electrode 4 and its periphery. The pH detection unit 8 is connected to the reading unit 10. The region a including the first electrode 4 and its periphery may be within 10 centimeters, within 7 centimeters, or within 5 centimeters from the downstream end of the first electrode 4 in the direction of flow of the sample solution 120 in a cross section along the height direction of the biosensor.

[0019] [Flow Channel] The flow channel 2 is not particularly limited as long as it can pass the sample solution 120 containing the biomarker 110. For example, it is preferably a microflow channel formed in the flow channel substrate 11 by a microfabrication method such as hydrogel molding, photolithography, soft lithography, cutting, or bonding, or a combination of these microfabrication methods. A microflow channel has an inner diameter (maximum diameter) on the order of nanometers to millimeters. Because the flow channel 2 is a microflow channel, the biomarker 110 can be detected with high sensitivity by the biosensor 1. Furthermore, the biomarker 110 bound to the recognition molecule 32 can be easily dissociated by a regeneration method described below. Examples of materials for the flow channel substrate 11 include silicone rubber, various resins other than silicone rubber, and glass.

[0020] [First Electrode] The first electrode 4 is not particularly limited as long as it is not deteriorated by the sample solution 120 and ions such as hydrogen ions and hydroxide ions, and in some cases, can immobilize the recognition molecule 32 on its surface 4a. Examples of the first electrode 4 include metal electrodes made of metals such as gold and platinum, and carbon-based electrodes. Examples of carbon-based electrodes include electrodes printed with carbon ink, glassy carbon electrodes, and boron-doped diamond electrodes.

[0021] [Second Electrode] The second electrode 5 is not particularly limited as long as it is not deteriorated by the sample solution 120 and ions such as hydrogen ions and hydroxide ions. Examples of the second electrode 5 include metal electrodes made of metals such as gold and platinum, and carbon-based electrodes. Examples of carbon-based electrodes include electrodes printed with carbon ink, glassy carbon electrodes, and boron-doped diamond electrodes.

[0022] [Current Application Means] The current application means 6 is not particularly limited as long as it can apply a current to the first electrode 4 and the second electrode 5. The current application means 6 is not particularly limited as long as it functions as a current generation source, and examples thereof include a current generator, a voltage / current generator, and the like.

[0023] The substrate 31 is not particularly limited as long as it can immobilize the recognition molecules 32 on its surface 31a and is not deteriorated by the sample solution 120 and ions such as hydrogen ions and hydroxide ions. Examples of the substrate 31 include a metal film made of a metal such as gold or platinum, and a carbon film.

[0024] [Recognition Molecule] The recognition molecule 32 is not particularly limited as long as it can capture the biomarker 110 contained in the sample solution 120, and examples thereof include antibodies, enzymes, and aptamers.

[0025] [Detection Means] The detection means 7 is not particularly limited as long as it functions as a detector, and is used depending on the application of the biosensor 1, i.e., the type of biomarker 110 to be detected by the biosensor 1. To detect the biomarker 110, a method is used in which a second recognition molecule modified with a labeling substance is bound to the biomarker 110 captured by the recognition molecule 32 (first recognition molecule), or a method is used that does not use a second recognition molecule modified with a labeling substance. In a method using a second recognition molecule, a detection means 7 is used that can perform a detection method appropriate for the second recognition molecule. Examples of the detection means 7 include a device that measures the fluorescence emitted by the second recognition molecule (label), a device that measures the absorbance of a substance produced by the reaction of the second recognition molecule (label) with a substrate, and a device that measures the redox current of a substance produced by the reaction of the second recognition molecule (label) with a substrate. Examples of methods that do not use a second recognition molecule, i.e., methods that directly measure the amount of biomarker 110 binding to recognition molecule 32, include surface plasmon resonance, quartz crystal microbalance, electrochemical impedance measurement, and surface acoustic wave measurement. Figure 1 illustrates an example of directly measuring the amount of biomarker 110 binding to recognition molecule 32 by surface plasmon resonance. In this case, detection means 7 has a light source 71 that irradiates sensor unit 3 with white light, and a detector 72 that detects the amount of change in the wavelength of light attenuated by surface plasmon resonance due to binding between biomarker 110 and recognition molecule 32.

[0026] [pH Detection Unit] Examples of the pH detection unit 8 include a pH meter. By providing the pH detection unit 8, it is not necessary to use a pH indicator to detect the pH of the sample solution 120. Furthermore, by providing the pH detection unit 8, the pH of the sample solution 120 can be detected immediately, and the pH of the sample solution 120 can be more easily controlled by adjusting the current applied to the first electrode 4 and the second electrode 5 by the current application means 6.

[0027] [Substrate] The substrate 9 is not particularly limited as long as it can be provided with the flow path substrate 11 on one surface 9a thereof, and examples thereof include a glass substrate, a resin substrate, etc. When the sensor unit 3 is composed only of the recognition molecules 32 fixed to the inner surface 2a of the flow path 2 (the inner surface 11a of the flow path substrate 11), the flow path substrate 11 is not particularly limited as long as it can fix the recognition molecules 32 to the inner surface 11a and is not deteriorated by the sample solution 120 and ions such as hydrogen ions and hydroxide ions.

[0028] [Biomarkers] Examples of biomarkers 110 include, but are not limited to, tumor markers that suggest the presence of cancer, such as CEA and AFP (alpha-fetoprotein), biomarkers that suggest heart disease, such as oxidized LDL and C-reactive protein (CRP), and biomarkers that suggest dementia, such as amyloid beta.

[0029] [Sample Solution] The sample solution 120 is a solution containing the biomarker 110. Specific examples of the sample solution 120 include body fluids such as blood, interstitial fluid, sweat, and saliva, and physiological saline solutions such as phosphate-buffered saline and Tris-buffered saline.

[0030] [Method of Using the Biosensor] A method of using the biosensor 1 of this embodiment will be described.

[0031] A sample solution 120 containing a biomarker 110 is flowed through the flow path 2. When the sample solution 120 is flowed through the flow path 2, the biomarker 110 contained in the sample solution 120 is captured by the recognition molecule 32 of the sensor unit 3. Next, the biomarker 110 is qualitatively or quantitatively analyzed by the detection means 7. Specifically, white light is irradiated onto the sensor unit 3 from the light source 71, and the amount of change in the wavelength of the light attenuated by surface plasmon resonance due to binding between the biomarker 110 and the recognition molecule 32 is detected by the detector 72, thereby qualitatively or quantitatively analyzing the biomarker 110. After detection of the biomarker 110 is completed, a current is applied by the current application means 6 using the first electrode 4 as an anode and the second electrode 5 as a cathode, causing a high concentration of hydrogen ions (H ＋As a result, the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery in the flow channel 2 becomes less than 7 (acidic). In addition, the flow of the sample solution 120 flowing in the flow channel 2 causes hydrogen ions (H ＋ ) flows toward the recognition molecule 32. As a result, the acidic sample solution 120 dissociates the biomarker 110 captured by the recognition molecule 32, and the recognition molecule 32 is restored to a state in which the biomarker 110 is not bound to the recognition molecule 32. This makes it possible for the recognition molecule 32 to capture the biomarker 110 contained in the sample solution 120 again.

[0032] According to the biosensor 1 of this embodiment, the current application means 6 applies a current using the first electrode 4 as an anode and the second electrode 5 as a cathode, thereby making it possible to make the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery less than 7. As a result, the acidic sample solution 120 dissociates the biomarker 110 captured by the recognition molecule 32, thereby restoring the recognition molecule 32 to a state in which the biomarker 110 is not bound. Furthermore, according to the biosensor 1 of this embodiment, the current application means 6 applies a current using the first electrode 4 as a cathode and the second electrode 5 as an anode, thereby making it possible to make the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery in the flow path 2 greater than 7. As a result, the alkaline sample solution 120 dissociates the biomarker 110 captured by the recognition molecule 32, thereby restoring the recognition molecule 32 to a state in which the biomarker 110 is not bound. Furthermore, unlike conventional methods, there is no need to use a liquid pump or valve to send a regenerating liquid such as an acid or alkali into the flow channel 2 in which the recognition molecule 32 is disposed in order to regenerate the recognition molecule 32, which makes it possible to easily regenerate the recognition molecule 32. Therefore, the biosensor 1 can be used repeatedly and continuously without being discarded. Furthermore, since the recognition molecule 32 can be regenerated without using large-scale equipment, the biosensor 1 can be made smaller.

[0033] [Method for Regenerating Recognition Molecules] A method for regenerating recognition molecules according to one embodiment of the present invention is a method for regenerating recognition molecules in the biosensor according to one embodiment of the present invention described above.

[0034] "First Regeneration Method" In the method for regenerating the recognition molecule of this embodiment, for example, in the biosensor 1, a current is applied by the current application means 6 between the first electrode 4 as an anode and the second electrode 5 as a cathode, thereby generating a high concentration hydrogen ion region near the surface 4 a of the first electrode 4, and controlling the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery in the flow path 2 to be less than 7.

[0035] The current applied to the first electrode 4 and the second electrode 5 is not particularly limited, but is preferably 30 μA or more and 1 mA or less, and more preferably 50 μA or more and 200 μA or less. If the current is less than 30 μA, the reaction amount of chloride ions and oxygen ions is small, making it difficult to manipulate the pH of the sample solution 120 present in the region α including the first electrode 4 and its periphery. If the current exceeds 1 mA, the amount of gas generated near the first electrode 4 increases or the pH becomes too low, increasing the risk of damaging the recognition molecule 32.

[0036] The flow rate of the sample solution 120 flowing through the flow channel 2 is not particularly limited, but is preferably, for example, 1 μl / min or more and 1 ml / min or less, and more preferably 10 μl / min or more and 200 μl / min or less.

[0037] In the flow channel 2, the pH of the sample solution 120 present in the region α including the first electrode 4 and its periphery is preferably controlled to 1 to 3.5, and more preferably to 2 to 3. Controlling the pH of the sample solution 120 to 1 to 3.5 can further promote dissociation of the biomarker 110 from the recognition molecule 32.

[0038] The sample solution 120 may contain a pH indicator. The pH indicator is not particularly limited as long as it can indicate a range from alkaline (pH 14) to acidic (pH 1), but examples include thymol blue, methyl red, and phenolphthalein. Thymol blue turns yellow at neutral pH and red at acidic pH. Thymol blue turns yellow at pH 3, and the closer to red the color, the lower the pH and the higher the acidity. If the sample solution 120 contains a pH indicator, the pH of the sample solution 120 present in the region α including the first electrode 4 and its surroundings can be confirmed by applying a current to the first electrode 4 and the second electrode 5. The pH indicator can be used to determine whether to continue applying a current to the first electrode 4 and the second electrode 5 or to stop applying a current to the first electrode 4 and the second electrode 5.

[0039] The biosensor 1 may also include a pH detection unit 8, such as a pH meter, that detects the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery. If the biosensor 1 includes the pH detection unit 8, the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery can be confirmed by applying a current to the first electrode 4 and the second electrode 5. The pH detection unit 8 makes it possible to immediately determine whether to continue applying a current to the first electrode 4 and the second electrode 5, or to stop applying a current to the first electrode 4 and the second electrode 5.

[0040] According to the method for regenerating a recognition molecule of this embodiment, by applying a current to the first electrode 4 and the second electrode 5 and controlling the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery to less than 7, the biomarker 110 captured by the recognition molecule 32 is dissociated, and the recognition molecule 32 can be regenerated to a state in which the biomarker 110 is not bound. Furthermore, unlike conventional methods, there is no need to use a liquid pump or valve to send a regenerating solution such as an acid or alkali into the flow channel 2 in which the recognition molecule 32 is disposed, so that the recognition molecule 32 can be regenerated easily. Therefore, the biosensor 1 can be used repeatedly and continuously. Furthermore, the recognition molecule 32 can be regenerated without using large-scale equipment.

[0041] "Second Regeneration Method" In the method for regenerating a recognition molecule of this embodiment, for example, in biosensor 1, current application means 6 applies a current to first electrode 4 as an anode and second electrode 5 as a cathode, generating a high-concentration hydrogen ion region near surface 4a of first electrode 4, and controlling the pH of sample solution 120 present in region a including first electrode 4 and its periphery in flow path 2 to less than 7. In the method for regenerating a recognition molecule of this embodiment, in biosensor 1, current application means 6 applies a current to first electrode 4 as a cathode and second electrode 5 as an anode, generating a high-concentration hydroxide ion region near surface 5a of second electrode 5, and controlling the pH of sample solution 120 present in region a including first electrode 4 and its periphery in flow path 2 to greater than 7.

[0042] The current applied to the first electrode 4 and the second electrode 5 is not particularly limited, but is preferably 30 μA or more and 1 mA or less, and more preferably 50 μA or more and 200 μA or less. If the current is less than 30 μA, the amount of hydrogen ions reacting is small, making it difficult to sufficiently manipulate the pH of the sample solution 120 present in the region α including the first electrode 4 and its periphery. If the current exceeds 1 mA, the amount of gas generated near the first electrode 4 increases, or the pH becomes too high, increasing the risk of damaging the recognition molecule 32.

[0043] The flow rate of the sample solution 120 flowing through the flow channel 2 is not particularly limited, but is preferably, for example, 1 μl / min or more and 1 ml / min or less, and more preferably 10 μl / min or more and 200 μl / min or less.

[0044] In the flow channel 2, the pH of the sample solution 120 present in the region α including the first electrode 4 and its periphery is preferably controlled to 10 or higher, more preferably 10 to 12, and even more preferably 11 to 12. By controlling the pH of the sample solution 120 to 10 or higher and 12 or lower, dissociation of the biomarker 110 from the recognition molecule 32 can be further promoted.

[0045] The sample solution 120 may contain a pH indicator. The pH indicator can be any indicator capable of indicating a range from alkaline (pH 14) to acidic (pH 1), but examples include alizarin yellow, thymol blue, methyl red, and phenolphthalein. Alizarin yellow is yellow at neutral pH and changes color to orange at alkaline pH. Alizarin yellow is yellow at pH 10, and the closer the color is to orange, the higher the pH and alkalinity. If the sample solution 120 contains a pH indicator, the pH of the sample solution 120 present in the region α, which includes the first electrode 4 and its surroundings, can be confirmed by applying a current to the first electrode 4 and the second electrode 5. The pH indicator can be used to determine whether to continue applying a current to the first electrode 4 and the second electrode 5 or to stop applying a current to the first electrode 4 and the second electrode 5.

[0046] In the second regeneration method, as in the second regeneration method, the biosensor 1 may be provided with a pH detection unit 8 such as a pH meter that detects the pH of the sample solution 120 present in the region α including the first electrode 4 and its surrounding area.

[0047] According to the method for regenerating a recognition molecule of this embodiment, by applying a current to the first electrode 4 and the second electrode 5 and controlling the pH of the sample solution 120 present in the region a including the first electrode 4 and its periphery to a value greater than 7, the biomarker 110 captured by the recognition molecule 32 is dissociated, and the recognition molecule 32 can be regenerated to a state in which the biomarker 110 is not bound. Furthermore, unlike conventional methods, there is no need to use a liquid supply pump or valve to supply a regenerating solution such as an acid or alkali into the flow channel 2 in which the recognition molecule 32 is disposed, so that the recognition molecule 32 can be regenerated easily. Therefore, the biosensor 1 can be used repeatedly and continuously. Furthermore, the recognition molecule 32 can be regenerated without using large-scale equipment.

[0048] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0049] [Example] Using the biosensor shown in Figure 1, a current was applied to the first and second electrodes while the sample solution was flowing through the flow channel, and the change in pH of the sample solution was measured. A pH meter was used to measure the pH of the sample solution. A 0.9% aqueous sodium chloride solution was used as the sample solution. The flow rate of the sample solution was 10 µl / min to 20 µl / min. The current applied to the first and second electrodes was 50 µA to 200 µA. The results are shown in Figure 2. The results shown in Figure 2 confirmed that the pH of the sample solution could be controlled to 2 to 3, which is effective for regenerating the recognition molecule.

[0050] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

[0051] The biosensor of the present invention can be used repeatedly and continuously, and therefore the biosensor can be miniaturized, making it possible to realize a wearable terminal incorporating a biosensor.

[0052] REFERENCE SIGNS LIST 1 Biosensor 2 Flow path 3 Sensor section 4 First electrode 5 Second electrode 6 Current application means 7 Detection means 8 pH detection section 9 Substrate 10 Reading section 11 Flow path substrate 32 Recognition molecule 110 Biomarker 120 Sample solution

Claims

1. A biosensor comprising: a flow path for flowing a sample solution containing a biomarker; a sensor portion disposed within the flow path and having a recognition molecule; a first electrode and a second electrode disposed spaced apart from each other within the flow path; a current application means for applying a current to the first electrode and the second electrode; and a detection means for detecting a biomarker captured by the recognition molecule.

2. The biosensor according to claim 1, further comprising a pH detection unit for detecting the pH of the sample solution present in an area including the first electrode and its periphery.

3. A method for regenerating a recognition molecule in a biosensor as described in claim 1 or 2, comprising applying a current to the first electrode and the second electrode by the current application means, and controlling the pH of the sample solution present in a region including the first electrode and its periphery within the flow path.

4. The method for regenerating a recognition molecule according to claim 3, wherein an antibody is used as the recognition molecule.

5. A method for regenerating a recognition molecule according to claim 3, wherein the pH of the sample solution present in the region including the first electrode and its periphery is controlled to be between 1 and 3.

5.

6. The method for regenerating a recognition molecule according to claim 3, wherein the pH of the sample solution present in the region including the first electrode and its periphery is controlled to 10 or higher.

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