JP2016045032A - Biomolecule detection element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to detect more accurately with higher sensitivity using a detection element in which a sensor sensitive part for a biomolecule detection molecule based on an aptamer is secured to a solid-state surface.SOLUTION: A biomolecule detection element is configured from a biomolecule detection molecule 100, a sensor sensitive part 111 configured from graphene, and a base substance 112 to which the sensor sensitive part 111 is secured. The biomolecule detection molecule 100 is provided with an aptamer 101 specifically binding to the biomolecule to be detected, a signal molecule 102 comprising a fluorescent dye molecule binding to the one end of the aptamer 101 and the outputted fluorescence of which changes in correspondence to the distance to the sensor sensitive part, and an adhesive molecule 103 binding to the other end of the aptamer 101 and bonding the aptamer 101 and the sensor sensitive part together.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a biomolecule detection element including a biomolecule detection molecule for detecting a target biomolecule.

  In the biomolecule detection method, a biomolecule detection molecule that selectively recognizes a target biomolecule to be detected is used, and a change in molecular structure or reaction caused by binding of the biomolecule detection molecule to a target biomolecule, such as a protein. There is a method for detecting a chemical phenomenon such as generation of a substance by converting it into a signal such as light or electricity. Biomolecule detection molecules used in this method include biological molecules (nucleic acid, amino acid, antibody, nucleic acid, lipid, sugar chain, ion channel, etc.). By utilizing the specific structural change of the biomolecule detection molecule caused by the binding between the target biomolecule and the biomolecule detection molecule, high selectivity with the target biomolecule can be ensured.

  As an example of a biomolecule detection molecule using structural change, an aptamer (ligand composed of a nucleic acid or a peptide that specifically binds to the target biomolecule) whose structure is changed by binding to the target biomolecule can be used. Aptamers are generally known to change to a specific structure by binding to a specific target biomolecule. Furthermore, the structure of aptamers after structural changes can be precisely designed by sequence design. Are known. A variety of biomolecules have been disclosed as aptamer target biomolecules. For example, various proteins, enzymes, peptides, antibodies, receptors, hormones, amino acids, antibiotics, and other various compounds have been reported. (See Non-Patent Document 1).

  In a biomolecule detection method using an aptamer, it is useful to modify (add) various signal molecules to a predesigned site of the aptamer as a technique for converting a structural change of the aptamer into a detectable signal. When an aptamer modified with a signal molecule forms a complex with a target biomolecule, the distance between the signal molecule and the substance that acts as the sensor changes, and the output signal changes. It becomes possible to do. The signal molecule used here varies depending on the detection method. For example, when fluorescence detection is used, various fluorescent molecules can be used as the signal molecule, and a fluorescent quencher (excitation energy absorbing substance) such as graphene oxide can be used for the sensor sensitive part (see Non-Patent Document 2).

  As the distance between the fluorescent molecule and the sensor sensitive part increases, the quenching efficiency of the sensor sensitive part decreases. This state can be observed (detected) by using, for example, a fluorescence microscope. In the configuration using a fluorescent molecule as a signal molecule, detection is performed using an increase in emission intensity due to the separation of the fluorescent molecule and the sensor sensitive part due to the formation of a complex between the target biomolecule and the aptamer (see Non-Patent Document 3). ). For this reason, in the initial stage before the detection of the target biomolecule, the fluorescent molecule modified (bound) to the aptamer is arranged as close as possible to the sensor-sensing part to maximize the quenching efficiency. It is desirable that On the other hand, after the aptamer forms a complex with the target biomolecule, it is desirable that the fluorescent molecule is moved away from the sensor sensitive part at a distance where quenching does not occur.

  Corresponding to the detection method using the above-described biomolecule detection molecule, a technology has been developed in which graphene oxide as a sensor sensitive part is immobilized on a solid surface to form a detection element (see Patent Document 1). In this technique, unlike the technique of Non-Patent Document 3 used as an aqueous dispersion in which small pieces of graphene oxide are dispersed, the surface of graphene oxide immobilized on a solid surface is chemically bonded in the order of adhesion molecule-aptamer-fluorescent dye. Modified with biomolecule detection molecules. Since the biomolecule detection element is immobilized on the solid surface, it is possible to mount a microchannel, and it has the advantage that a plurality of samples can be detected simultaneously and a quantitative comparison can be made.

  In Patent Document 1, a method of applying an aqueous dispersion of graphene oxide to a solid surface is used in order to fix the graphene oxide to the solid surface. Here, since such a sensor operation is performed only on the surface of graphene oxide, the coverage of graphene oxide and the signal intensity are in a proportional relationship. In addition, the detection sensitivity is different between a portion where one layer and two or more layers overlap. These means that when the coverage of graphene oxide is different, quantitative comparison of the detection target is impossible. Therefore, for more accurate detection, it is important that the graphene oxide cover the solid surface with a high density, ideally with no exposed sites on the solid surface.

  However, normal graphene oxide has dimensional variations, and includes a maximum of about 100 μm square and a small one of several tens of nm square. Due to the non-uniform shape of graphene oxide and the non-uniformity of the coating process, the graphene oxide layer is not spread and there is no area where the solid surface is exposed, or there is no area where graphene oxide overlaps two or more layers. It is extremely difficult to produce a solid surface with a coverage of 100%. For this reason, the above-described technique has a problem that more accurate detection may not be possible.

  Further, in the method of Patent Document 1, a molecule in which a plurality of benzene rings are bonded as adhesion molecules to graphene oxide, for example, benzene and polycyclic aromatic molecules (naphthalene, anthracene, tetracene, pentacene, phenanthrene, pyrene, perylene, coronene), Is used. These adhesion molecules act on a graphene-like structure site contained in graphene oxide, and play a role of fixing biomolecule detection molecules on the surface of graphene oxide.

  Graphene oxide has a structure in which oxidized amorphous structure portions and graphene-like structure portions are mixed in a mosaic pattern. In order to improve sensitivity, it is important to modify graphene oxide with more biomolecule detection molecules. However, when graphene oxide is used as the sensor sensitive part, there is a problem that the maximum value of the number density of molecules to be modified is limited by the ratio of the graphene-like structural sites in the graphene oxide.

JP2013-253825A

T. Hermann and D. J. Patel, "Adaptive Recognition by Nucleic Acid Aptamers", SCIENCE, vol.287, pp.820-825, 2000. E. Treossi et al., "High-Contrast Visualization of Graphene Oxide on Dye-Sensitized Glass, Quartz, and Silicon by Fluorescence Quenching", J. AM. CHEM. SOC., Vol.131, pp.15576-15577, 2009 . H. Chang et al., "Graphene Fluorescence Resonance Energy Transfer Aptasensor for the Thrombin Detection", Analytical Chemistry, vol.82, no.6, pp.2341-2346, 2010. K. S. Novoselov et al., "Electric Field Effect in Atomically Thin Carbon Films", SCIENCE, vol.306, pp.666-669, 2004. A. J. van Bommel et al., "LEED AND AUGER ELECTRON OBSERVATIONS OF THE SiC (0001) SURFACE", Surface Science, VOL.48, PP463-472, 1975. A. Reina ET AL., "Large Area, Few-Layer Graphene Films on Arbitrary Substrates by Chemical Vapor Deposition", Nano Letters, vol.9, no.1, pp.30-35, 2009. X. Li et al., "Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils", SCIENCE, vol.324, pp.1312-1314, 2009. F. Maeda and H. Hibino, "Thin Graphitic Structure Formation on Various Substrates by Gas-Source Molecular Beam Epitaxy Using Cracked Ethanol", Japanese Journal of Applied Physics, vol.49, 04DH13, 2010.

  As described above, when graphene oxide is immobilized on a sensor-sensitive part of a biomolecule detection molecule by an aptamer and used for detection, there is a problem that accurate detection cannot be performed and high sensitivity cannot be detected. It was.

  The present invention has been made to solve the above-described problems, and is a detection element in which a sensor-sensitive part of a biomolecule detection molecule by an aptamer is fixed on a solid surface, and can detect more accurately and with higher sensitivity. The purpose is to be able to.

  The biomolecule detection element according to the present invention includes an aptamer that specifically binds to a biomolecule to be detected, a fluorescent dye that binds to one end of the aptamer, and the output fluorescence changes in accordance with the distance from the sensor sensing part. A signal molecule consisting of molecules, an adhesion molecule that binds to the other end of the aptamer and adheres the aptamer to the sensor sensitive part, and a biomolecule detection molecule consisting of the aptamer, signal molecule, and adhesion molecule are adhered by the adhesion molecule. A sensor-sensitive part made of graphene and a base body to which the sensor-sensitive part is fixed.

  The adhesion molecule only needs to contain pyrene in the skeleton. The adhesion molecule may be pyrene butyric acid.

  As described above, according to the present invention, it is possible to obtain an excellent effect that more accurate and higher sensitivity can be detected with the detection element in which the sensor-sensitive part of the biomolecule detection molecule by the aptamer is fixed to the solid surface.

FIG. 1 is a configuration diagram showing a configuration of a biomolecule detection element according to an embodiment of the present invention. FIG. 2 is a configuration diagram showing the configuration of the biomolecule detection element according to the embodiment of the present invention. FIG. 3 is a flowchart for explaining the production of the biomolecule detection element according to the embodiment of the present invention. FIG. 4 is a flowchart for explaining the production of the biomolecule detection element in the embodiment of the present invention. FIG. 5 is a characteristic diagram showing the results of detecting PSA using the biomolecule detection element in Example 1. 6 is a photograph showing a state observed with a fluorescence microscope when PSA was detected using the biomolecule detection element in Example 1. FIG. FIG. 7 is a characteristic diagram showing the results of detecting PSA using the biomolecule detection element in Example 2. FIG. 8 is a photograph showing a state observed with a fluorescence microscope when PSA was detected using the biomolecule detection element in Example 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a configuration of a biomolecule detection element according to an embodiment of the present invention. This biomolecule detection element is composed of a biomolecule detection molecule 100, a sensor sensitive part 111 made of graphene, and a base body 112 to which the sensor sensitive part 111 is fixed.

  The biomolecule detection molecule 100 includes an aptamer 101 that specifically binds to a biomolecule to be detected, and a fluorescent dye molecule that binds to one end of the aptamer 101 and whose output fluorescence changes according to the distance from the sensor sensing part. And an adhesion molecule 103 that binds to the other end of the aptamer 101 and adheres the aptamer 101 and the sensor sensitive part. The “aptamer” indicates a part that specifically binds to a biomolecule to be detected.

  In the biomolecule detection element in the above-described embodiment, the sensor sensitive part 111 made of graphene functions as a fluorescence quencher of the signal molecule 102 made of a fluorescent dye molecule, and the distance between the signal molecule 102 and the sensor sensitive part 111. Can be detected as a change in the electrical signal.

  Further, the adhesion molecule 103 may be composed of a molecule that physically adsorbs to the sensor sensitive part 111. For example, since the sensor sensitive part 111 is made of graphene, which is a carbon material, the adhesion molecule 103 is composed of benzene and polycyclic aromatic molecules (naphthalene, anthracene, tetracene, pentacene, phenanthrene, pyrene, perylene, coronene). Any molecule included in the skeleton may be used. These molecules can be adsorbed (adhered) to graphene, which is a carbon material. Further, the adhesion molecule 103 may be a molecule that is chemically bonded to the sensor sensitive part 111 made of graphene.

  In the biomolecule detection element according to the present embodiment, as shown in FIG. 2, even when the aptamer 101 forms a complex with the biomolecule 201 to be detected, the aptamer 101 adheres to the sensor sensing part 111 with the adhesion molecule 103. Therefore, the biomolecule detection molecule 100 is not detached from the sensor sensing part 111. As a result, even if a complex is formed as described above, the signal output from the signal molecule 102 can be detected at the sensor sensitive part 111, and the signal molecule 102, the sensor sensitive part 111, The detection signal generated by the change in the distance can be detected near the surface of the sensor sensing unit 111.

  For example, the substrate 112 is a substrate that serves as a detection surface of a chip-type device, and on this detection surface, biomolecules can be detected using the biomolecule detection molecule 100.

  Here, the present invention has been made based on the knowledge that graphene has an effect of quenching fluorescence with high efficiency in the same manner as graphene oxide, as a result of diligent studies by the inventors. In the biomolecule detection molecule 100 in which the signal molecule 102 is composed of the fluorescent molecule (fluorescent dye molecule), it is important that the sensor sensitive part 111 is composed of a fluorescent quencher (excitation energy absorbing substance). Conventionally, it has been known that graphene oxide is a fluorescent quencher, but it has not been known that graphene is used as a fluorescent quencher. In contrast, the inventors have found that graphene functions as a fluorescence quencher.

Here, graphene has a honeycomb-like structure entirely composed of double bonds of carbon atoms (sp ² hybrid orbitals), and is composed of naphthalene, anthracene, tetracene, pentacene, phenanthrene, pyrene, perylene, coronene, etc. The adhesion molecule 103 can be adhered to any part of the surface. Therefore, graphene is suitable for immobilizing the biomolecule detection molecule 100, and according to the sensor sensitive part 111 made of graphene, it is easy to modify the entire area of the sensor sensitive part 111 with the biomolecule detection molecule 100. .

  In addition, graphene can be manufactured in a large area with only one layer. For example, graphene can be formed on an arbitrary substrate by a graphite peeling method (see Non-Patent Document 4). Further, by using a silicon carbide (SiC) substrate and thermally decomposing the surface, single-layer and multilayer graphene can be formed on the surface of the SiC substrate (see Non-Patent Document 5). Further, graphene formed by chemical vapor deposition may be transferred onto a desired substrate (see Non-Patent Documents 6 and 7). In addition, graphene can be formed by molecular beam epitaxy (see Non-Patent Document 8).

  Therefore, according to the biomolecule detection element using graphene as the sensor sensitive part 111, it is easy to produce the surface of the substrate 112 with a coverage of 100% by the sensor sensitive part 111 composed of one graphene layer.

  From the above, according to the biomolecule detection element of the embodiment, more accurate and higher sensitivity detection can be performed.

  Hereinafter, the manufacturing method of the biomolecule detection element in embodiment is demonstrated. As a method of chemically binding the signal molecule and the adhesion molecule to the aptamer, an amino group or the like is introduced at one end of the aptamer, and the carboxyl group or N-hydroxysuccinimide ester site introduced into the signal molecule or the adhesion molecule is reacted therewith. The method of forming a chemical bond is preferable.

  Various methods can be used as a method for adhering the aptamer to the surface of the sensor-sensitive part made of graphene. For example, as shown in FIG. 3, after producing a sensor sensitive part (graphene) in step S301 and fixing the graphene produced in step S302 to a substrate to be a chip, in step S303, N- An adhesion molecule having a hydroxysuccinimide ester moiety is adhered (adsorbed). On the other hand, in step S304, an aptamer is synthesized. In step S305, a signal molecule is bound to one end of the synthesized aptamer, and an amino group (adhesion molecule binding site) is introduced to the other end.

  Thereafter, in step S306, the amino group portion of the aptamer to which the signal molecule is bonded and the amino group is introduced may be bonded to the adhesion molecule adsorbed on the surface of the sensor sensitive part. Aptamers in which a fluorescent dye molecule or the like is bonded to one end and an amino group is introduced to the other end can be obtained from a reagent manufacturer that performs custom synthesis of nucleic acids and peptides.

  Here, step S302 can be omitted depending on a graphene production mode. For example, if graphene is produced by thermally decomposing the SiC surface, the graphene can be obtained as already fixed on the SiC substrate. In this case, it is not necessary to fix the produced graphene to another substrate, and if an SiC substrate is used as a base, step S302 can be omitted.

  Further, as shown in FIG. 4, in step S401, graphene is produced, and the graphene produced in step S302 is fixed to a substrate to be a chip. On the other hand, in step S403, an aptamer is synthesized, and in step S404, a signal molecule is bound to one end of the synthesized aptamer, and an adhesion molecule is bound to the other end. Thereafter, in step S405, the aptamer adhesion molecule to which the signal molecule and the adhesion molecule are bonded may be adhered (adsorbed) to the graphene surface.

  Control of the density of the aptamer (biomolecule detection molecule) adhered to the graphene surface is achieved by controlling the fixing time, aptamer concentration, reaction temperature, and the like. This density can be confirmed by various analysis methods such as quartz crystal microbalance (QCM) method, surface plasmon resonance (SPR) method, X-ray photoelectron spectroscopy (XPS) method, and atomic force microscope (AFM) method. is there.

  In addition, a glass substrate, a quartz substrate, a silicon substrate, or the like can be used as a substrate for fixing a biomolecule detection element in which biomolecule detection molecules are bonded to graphene. Note that a metal film or the like may be deposited on these substrates.

  In the biomolecule detection chip to which the biomolecule detection element is fixed, the sample solution may be dropped directly on the detection unit. In addition, the sample solution may be introduced into the detection unit on which the biomolecule detection element is fixed by mounting a flow path. Various materials can be applied to the flow path, and various methods can be used to manufacture the flow path, but a method of manufacturing a polymer resin such as polydimethylsiloxane using a mold is preferable. You may produce by injection molding etc. using resin, such as polystyrene. Furthermore, you may shape | mold by processing a glass plate, a quartz plate, an acrylic board etc. using the milling method.

  The width of the flow path is preferably about 100 μm to 1000 μm, the height of the flow path is about 10 μm to 500 μm, and the length of the flow path is preferably about 1 mm to 10 mm. In the channel having this dimension, it is possible to easily send the solution by utilizing the capillary phenomenon, and it is not necessary to use an external driving force such as a pump. When a plurality of flow paths are arranged in parallel, the interval between adjacent flow paths is preferably 10 μm or more in order to avoid liquid leakage from different flow paths.

[Example 1]
First, Example 1 will be described. Graphene produced by a general manufacturing method can be used. For example, a method of exfoliating graphite, a method of thermally decomposing silicon carbide, a method by chemical vapor deposition, a method by molecular beam epitaxy growth and the like can be mentioned (see Non-Patent Documents 4-8).

  In Example 1, a graphene obtained by transferring chemical vapor grown graphene on a copper foil onto a silicon wafer on which a silicon oxide layer having a layer thickness of 300 nm is formed is used (purchased from a silicon platform stock). A substrate (graphene transfer substrate) obtained by dividing the silicon wafer onto which the graphene was transferred into a size of 1 cm square was used.

  Next, introduction of adhesion molecules to the graphene surface will be described. In introducing the adhesion molecule, the graphene transfer substrate is allowed to stand at room temperature for 1 hour in a 0.5 mM dimethylformamide solution of pyrenebutyric acid succinimide ester in which the COOH group of pyrenebutyric acid is activated with succinimide. This is washed with dimethylformamide and then air dried.

  Next, an aqueous solution (100 μM) of an aptamer in which a fluorescent dye molecule (signal molecule) is bonded to the 3 ′ end in advance and an amino group is bonded to the 5 ′ end is dropped onto graphene. Next, these are allowed to stand at room temperature (about 23 ° C.) for 1 hour, and the COOH group of pyrenebutyric acid adsorbed on graphene reacts with the amino group bonded to the 5 ′ end of the aptamer, via a peptide bond. And combine. This is washed with ultrapure water and air-dried. By these things, the aptamer to which both the pyrene butyric acid which is an adhesion molecule and the fluorescent dye molecule which is a signal molecule are bonded is fixed to the graphene surface on the substrate.

  As the aptamer, for example, 5′-TTTAATTAAAGCTCTCCCATCAAATAGCTTTTTTTTTTT-3 ′ containing a sequence that specifically binds to PSA which is a prostate cancer marker can be used. In addition, 6-carbofluorescein (FAM) can be bound to the 3 ′ end as a fluorescent dye molecule. In the detection chip thus manufactured, the state where the adhesion molecules are adhered to the graphene surface can be confirmed by an analysis method such as an AFM method.

  The biomolecule detection element according to the present invention produced by the above steps was observed using a confocal laser fluorescence microscope. First, ultrapure water was dropped to measure the fluorescence image of the graphene surface. On the surface of graphene, FAM bonded to the aptamer is arranged, but the fluorescence intensity is very weak. Since the distance between FAM and graphene (sensor sensing part) is short, it indicates that the fluorescence from the FAM is quenched by the energy transfer.

  Next, a 100 μg / ml PSA aqueous solution was dropped while observing the fluorescent image. FIG. 5 is a graph in which fluorescence intensity is plotted every 20 seconds from before dropping PSA to after dropping. PSA was dropped just before (b) in FIG.

  PSA is a biomolecule to be detected, and specifically binds to the aptamer described above. In the device of Example 1, an increase in the fluorescence intensity on the graphene surface was observed immediately after the dropping, and as shown in FIG. 5, it was observed that the intensity reached the maximum after several tens of seconds and gradually decreased. Further, before the PSA aqueous solution dropping shown in FIG. 5 (a), as shown in FIG. 6 (a), no light emission is confirmed in the detection unit, but immediately after the PSA aqueous solution dropping shown in FIG. 5 (b). As shown in FIG. 6B, light emission was clearly confirmed. The emission color was green. FIG. 6 is a photograph showing a fluorescence microscope observation image.

  These results indicate that the aptamer and PSA are selectively bound to change the three-dimensional structure of the aptamer, so that the FAM bound to the aptamer is separated to such an extent that energy transfer to graphene does not occur. This can be explained by emitting light.

  From the above, according to Example 1, using the present invention, even after the aptamer forms a complex with the target biomolecule, the biomolecule detection molecule exists on the graphene that is the sensor sensitive part. The problem that the fluorescent dye molecule is completely detached from the graphene together with the biomolecule detection molecule can be avoided. Further, the effect of the present invention was shown that a detection signal generated by a change in the distance between the fluorescent dye molecule and the graphene surface can be detected on the substrate surface on which the graphene is fixed. Thereby, it was shown that the biomolecule detection element by this invention is realizable.

[Example 2]
Next, Example 2 will be described. Similar to Example 1 described above, the graphene surface was modified with a biomolecule detection molecule. As in Example 1, the PSA aqueous solution was dropped while observing the fluorescent image on the graphene surface of the fabricated device. Further, pure water was dropped at regular intervals to reduce the PSA concentration. The change in fluorescence intensity at this time is shown in FIG.

  First, 40 μL of pure water was dropped, and when the fluorescence image on the graphene surface of the fabricated device was observed, the fluorescence intensity was very weak as shown in FIG. Since the distance between FAM and graphene is close, it indicates that the fluorescence from FAM is quenched by the energy transfer.

  100 seconds after the start of the observation, an additional 100 μg / ml PSA aqueous solution was added dropwise. Immediately after the dropping, an increase in the fluorescence intensity on the graphene surface was observed as shown in FIG. Further, after 200 seconds had passed, when 40 μL of pure water was further added dropwise, the fluorescence intensity further decreased immediately after the addition, as shown in FIG. As shown in (d) to (f) of FIG. 7, when the operation of adding 40 μL of pure water additionally every 200 seconds is repeated three more times, the result that the fluorescence intensity decreases each time pure water is added. Obtained. This indicates that the device of the present invention gives fluorescence intensity corresponding to the concentration of PSA.

[Example 3]
Next, Example 3 will be described. Similar to Example 1 described above, the graphene surface was modified with a biomolecule detection molecule. As in Example 1, the PSA aqueous solution was dropped while observing the fluorescent image on the graphene surface of the fabricated device. An increase in the fluorescence intensity on the graphene surface was observed immediately after the dropping.

  Next, the element after measurement was exposed to pure water for 1 to 2 minutes to clean the graphene surface. The cleaned element was air-dried and stored in the dark as it was. Similar observations were made again using elements stored in the dark for 3 days. That is, the PSA aqueous solution was dropped while observing the fluorescent image on the graphene surface of the stored element.

  As a result, before the dropping, no light emission is confirmed in the detection unit as shown in FIG. 8A, but immediately after the PSA aqueous solution is dropped, the light emission is clearly confirmed as shown in FIG. 8B. It was. The emission color was green. FIG. 8 is a photograph showing a fluorescence microscope observation image.

  Furthermore, it was confirmed that the device of the present invention showed the same sensor response to PSA even after three cycles of measurement → cleaning → reuse. From this, it was shown that the aptamer bonded to FAM that was employed on the graphene surface was not detached from the graphene surface even after selectively binding to PSA and after washing.

  As described above, according to the present invention, since the sensor sensitive part as a fluorescence quencher is made of graphene, the sensor sensitive part of the biomolecule detection molecule by the aptamer is fixed on the solid surface. , More accurate and higher sensitivity detection will be possible.

  The present invention is not limited to the embodiment described above, and many modifications and combinations can be implemented by those having ordinary knowledge in the art within the technical idea of the present invention. It is obvious. For example, the aptamer is not limited to a nucleic acid, but may be a peptide. In addition, a molecule in which a nucleic acid or a peptide is arranged may be bonded to the end of an aptamer to which a signal molecule or an adhesion molecule is bonded.

Adhesion molecules are not limited to those containing pyrene in the skeleton, such as pyrene butyric acid, but include, for example, benzene and polycyclic aromatic molecules (naphthalene, anthracene, tetracene, pentacene, phenanthrene, pyrene, perylene, coronene), etc. There may be. The functional group (molecule) that binds the adhesion molecule to the aptamer is not limited to butyric acid, and may be “—COOH” and “— (CH ₂ ) _n COOH”. Note that n is preferably in the range of 2 to 10.

  DESCRIPTION OF SYMBOLS 100 ... Biomolecule detection molecule, 101 ... Aptamer, 102 ... Signal molecule, 103 ... Adhesion molecule, 111 ... Sensor sensitive part, 112 ... Base | substrate.

Claims (3)

An aptamer that specifically binds to the biomolecule to be detected;
A signal molecule composed of a fluorescent dye molecule that binds to one end of the aptamer and changes the output fluorescence corresponding to the distance from the sensor sensitive part,
An adhesion molecule that binds to the other end of the aptamer and adheres the aptamer and the sensor sensitive part;
A biosensor for detecting a molecule composed of the aptamer, the signal molecule, and the adhesion molecule is composed of graphene bonded with the adhesion molecule;
A biomolecule detection element comprising: a substrate on which the sensor sensing part is fixed. The biomolecule detection element according to claim 1, wherein
The biomolecule detection element, wherein the adhesion molecule contains pyrene in a skeleton. The biomolecule detection element according to claim 2,
The biomolecule detection element, wherein the adhesion molecule is pyrene butyric acid.