Metamaterial sensing platform based on nanodisk structure

Abstract

The present invention relates to a metamaterial sensing platform comprising: a sensing unit for collecting particles; and a terahertz sensor unit for sensing the particles by allowing terahertz electromagnetic waves to be incident on the sensing unit; wherein the sensing unit includes a base substrate and a particle collection unit disposed on the base substrate and having a plurality of slits in which the particles are collected, and nanodisks reacting with the particles are disposed in the plurality of slits.

Description

Metamaterial sensing platform based on nanodisk structures

[0001] The present invention relates to a metamaterial sensing platform, and more particularly, to a metamaterial sensing platform capable of detecting particles of low-molecular-weight substances by applying a resonance frequency in the terahertz band by introducing a nanodisk structure utilizing a biological protein as a receptor protein for a target substance.

[0002] [Cross-reference to related applications]

[0003] This application claims priority to Republic of Korea Patent Application No. 10-2023-0133512, filed October 6, 2023, and Republic of Korea Patent Application No. 10-2023-0137936, filed October 16, 2023, the entire contents of which are incorporated herein by reference.

[0004] [Description of Nationally Supported Research and Development]

[0005] This research was conducted at the Korea Institute of Science and Technology (KIST) under the management of the Korea Institute of Science and Technology (KIST) under the Ministry of Science and ICT. The research project name is KIST Research Operation Expense Support (Main Project Expense), and the research project name is Development of Intelligent Solution Technology for Disaster Safety (Project Identification Number: 1711196504).

[0006] In addition, this study was conducted at the Korea Research Institute of Bioscience and Biotechnology under the management of the National Research Council of Science and Technology under the Ministry of Science and ICT. The research project name is the Korea Institute of Science and Technology Research Operational Expenses Support (Main Project Expenses), and the research project name is Development of Neurotransmitter Detection Device and Depression Monitoring Technology (Project Unique Number: 1711174963).

[0007]

[0008] In modern society, most diseases can be treated thanks to the advancement of diagnostic and medical technologies. However, there is still a need for treatment technologies for diseases that have not yet been conquered, such as cancer, and diseases whose pathogenesis is not clearly known, such as depression and dementia.

[0009] For example, in the case of cancer, the use of small molecule markers allows for real-time diagnosis using exhaled breath in daily life through a non-invasive diagnostic method, unlike conventional biopsy or endoscopic examinations. However, commercialization is difficult due to the lack of sensor technology capable of capturing and detecting small molecule substances with appropriate performance.

[0010] In addition, in the case of depression, several small-molecule biomarkers believed to be involved in the onset of depression are known, but the technology to accurately detect and quantify them is lacking.

[0011] Conventionally utilized technologies such as electrochemical or immunological biosensors require expensive equipment and consumable test papers, or have only a one-time diagnostic effect due to the use of irreversible reactions.

[0012] In particular, electrochemical blood glucose sensors have the problem of requiring blood sampling, and immunological biosensors can only be applied to large substances at the protein level, so they lack the diagnostic capability for small-molecule substances that are attracting attention as disease biomarkers in clinical settings.

[0013]

[0014] Therefore, the present invention aims to provide a novel sensing platform capable of capturing and detecting low-molecular-weight substances.

[0015]

[0016] In order to achieve the above-described technical task, the present invention can provide a metamaterial sensing platform including a sensing unit that captures particles; and a terahertz sensor unit that senses particles by irradiating terahertz electromagnetic waves onto the sensing unit; wherein the sensing unit includes a base substrate, a particle capturing unit formed with a plurality of slits for capturing particles and disposed on the base substrate, and nanodisks that react with particles are disposed in the plurality of slits.

[0017] In addition, the base substrate of the present invention is a Si layer, and an SiO2 layer obtained by oxidizing the Si layer may be additionally disposed between the Si layer and the particle collecting section.

[0018] Additionally, the nanodisk of the present invention can be attached to a SiO2 layer via an amine group.

[0019] In addition, the particle collecting portion of the present invention is a Au layer, the thickness of the Au layer can be 150 nm, and the nanodisks can be arranged at a height of 30 nm or less from the SiO2 surface.

[0020] In addition, the nanodisk of the present invention includes G protein-coupled receptors (GPCRs), and can be assembled by mixing G protein-coupled receptors produced from E. coli cells and membrane supporting proteins produced from E. coli cells.

[0021] Additionally, the plurality of slits of the present invention can be formed by etching the particle collecting portion in a negative manner using a photolithography method so that the SiO2 surface is exposed.

[0022] In addition, the terahertz sensor unit of the present invention can sense particles by incident terahertz electromagnetic waves onto the sensing unit and detecting terahertz electromagnetic waves reflected from the sensing unit.

[0023] In addition, particles can be sensed by measuring the reflectivity and frequency shift between the terahertz electromagnetic wave incident on the sensing unit of the present invention and the terahertz electromagnetic wave reflected from the sensing unit.

[0024]

[0025] The present invention can provide a metamaterial sensing platform with high sensitivity by imparting material and location selectivity by utilizing a nanodisk structure.

[0026] In addition, the present invention can provide a metamaterial sensing platform that can non-destructively perform qualitative and quantitative analysis of sensing target particles without relying on label particles by utilizing terahertz frequency-based spectroscopy.

[0027]

[0028] FIG. 1 is a conceptual diagram schematically illustrating a metamaterial sensing platform according to one embodiment of the present invention.

[0029] FIG. 2 is a conceptual diagram schematically illustrating a particle collection unit of a metamaterial sensing platform according to one embodiment of the present invention.

[0030] FIG. 3a and FIG. 3b are conceptual diagrams schematically showing before and after a sensing target particle is captured in a particle collection unit of a metamaterial sensing platform according to one embodiment of the present invention.

[0031] FIG. 4 is a conceptual diagram schematically illustrating a nanodisk of a metamaterial sensing platform according to one embodiment of the present invention.

[0032] FIG. 5 is a schematic chemical formula showing an amine group bonded to a SiO2 layer of a metamaterial sensing platform according to one embodiment of the present invention.

[0033] FIG. 6 schematically illustrates the intensity of an electric field focused at a slit of a particle collection unit using a metamaterial sensing platform according to one embodiment of the present invention.

[0034] FIGS. 7a and 7b are graphs showing the signal change rate detected using a metamaterial sensing platform according to one embodiment of the present invention.

[0035] FIG. 8 is a graph showing the amplification ratio of a detection signal using a metamaterial sensing platform according to one embodiment of the present invention.

[0036]

[0037] Hereinafter, a metamaterial sensing platform (1) according to one embodiment of the present invention will be described through a preferred embodiment of the present invention based on the attached drawings.

[0038] Before the explanation, in various embodiments, components having the same configuration will be described representatively in one embodiment using the same symbols, and in other embodiments, only different components will be described.

[0039] FIG. 1 is a conceptual diagram schematically illustrating a metamaterial sensing platform (1) according to one embodiment of the present invention.

[0040] As illustrated in FIG. 1, a metamaterial sensing platform (1) according to one embodiment of the present invention includes a sensing unit (10) that captures a sensing target particle and a terahertz sensor unit (20) that senses the sensing target particle by irradiating a terahertz electromagnetic wave onto the sensing unit (10).

[0041] Specifically, the sensing unit (10) is composed of a base substrate (100) and a particle collecting unit (200) having a plurality of slits (201) formed on the base substrate (100) to collect sensing target particles (T), and nanodisks (300) that react with the sensing target particles (T) can be placed in the plurality of slits (201).

[0042] The base substrate (100) may be a substrate capable of reflecting terahertz electromagnetic waves. For example, the base substrate (100) may be a silicon (Si) substrate, but is not limited thereto.

[0043] In addition, the particle collecting unit (200) formed on the base substrate (100) may be a structure designed to collect particles (T) that are the sensing target and focus terahertz electromagnetic waves on the collected particles. The structure of the particle collecting unit (200) itself may be referred to as a metamaterial.

[0044] Meanwhile, the terahertz sensor unit (20) is configured to irradiate terahertz electromagnetic waves onto the base substrate (100) of the metamaterial. These terahertz electromagnetic waves are transmitted at a rate of 10 per second. 12 It can be defined as an electromagnetic wave that reaches the range of 0.1 to 10 THz based on the frequency (1 THz) that vibrates as much as that, and electromagnetic waves in this range have non-ionizing characteristics and are harmless to the human body if they do not exceed the threshold.

[0045] As illustrated in FIG. 1, the terahertz sensor unit (20) is located at the bottom of the base substrate (100) of the metamaterial, and can input terahertz electromagnetic waves from the incident unit (21) onto one surface of the base substrate (100), and focus the terahertz electromagnetic waves reflected from one surface of the base substrate (100) of the metamaterial to sense the target particles (T) captured in the metamaterial (10) at the detector (22).

[0046] That is, by utilizing electromagnetic waves in the terahertz band applied to the metamaterial sensing platform (1) according to one embodiment of the present invention, it is possible to experimentally observe a hormone biomarker, which is a low-molecular-weight substance, through reflectance and frequency shift by measuring the reflection signal value detected by the effect of the sensing target particle (T) being captured in the nanodisk (300).

[0047] Therefore, since electromagnetic waves in the terahertz band do not penetrate the sensing target material but measure the reflected signal value, a sensor platform capable of sensing without damaging the sensing target material can be provided.

[0048] FIG. 2 is a conceptual diagram schematically showing a particle collection unit (200) of a metamaterial sensing platform (1) according to an embodiment of the present invention, and FIGS. 3a and 3b are conceptual diagrams schematically showing before and after a sensing target particle (T) is captured by a particle collection unit (200) of a metamaterial sensing platform (1) according to an embodiment of the present invention.

[0049] As shown in FIGS. 2 and 3, the particle collection unit (200) may have a layered structure in which a plurality of slits (201) are formed in which the sensing target particles (T) are captured.

[0050] Specifically, the particle collection unit (200) is composed of a conductive layer formed on a base substrate (100).

[0051] As such a conductive layer, a metal selected from the group consisting of copper, gold, silver, platinum and palladium; an alloy or composite containing at least one metal selected from the group consisting of copper, gold, silver, platinum and palladium and at least one substance selected from the group consisting of graphite, tellurium, tungsten, zinc, iridium, ruthenium, arsenic, phosphorus, aluminum, manganese and silicon may be selected, but is not limited thereto.

[0052] In one embodiment of the present invention, Au was used as a material for the particle collecting unit (200), and a SiO2 layer (101) was placed as an insulating layer between the base substrate (100) and the particle collecting unit (200), but this insulating layer can be formed without limitation using a non-conductive material having insulating properties.

[0053] For example, the insulating layer may be formed of, but is not limited to, a metal oxide such as SiO2, Nb2O5, TiO2, Al2O3, or MgO, or a polymer such as polyvinylpyrrolidone (PVP).

[0054] In one embodiment of the present invention, the Si layer, which is the base substrate (100), is partially oxidized to form a SiO2 layer, thereby imparting surface properties so as to have reactivity capable of attaching a chemical functional group to the surface of the SiO2 layer.

[0055] Meanwhile, the particle collection unit (200) includes a plurality of slits (201) patterned in a negative manner so that the surface of the SiO2 layer (101) disposed on the upper portion of the base substrate (100) is exposed.

[0056] Specifically, the plurality of slits (201) may be empty space portions etched in the shape of square columns in the Au layer, and the plurality of slits (201) may be formed in the same pattern.

[0057] As illustrated in FIG. 2, a plurality of slits (S) can be formed in a matrix form in the particle collection unit (200) with a plurality of holes having a certain width and length at a certain interval, so that a large number of negative patterns can be produced on a large area of ​​a wafer scale through a photolithography method.

[0058] These multiple slits (201) can concentrate terahertz electromagnetic waves in a certain region relative to the wavelength beyond the wavelength limit. That is, the terahertz electromagnetic waves can be concentrated and amplified by the multiple slits (201), thereby increasing the measurement efficiency for trace particles, and the frequency and focusing depth of the terahertz electromagnetic waves can be controlled depending on the width, thickness, and length of the slits (201).

[0059] In one embodiment of the present invention, a 150 nm gold thin film layer was etched to form a slit (201), and the slit (201) was etched to a width of 500 nm so as to expose the surface of the SiO2 layer (101) of the base substrate (100).

[0060] FIG. 4 is a conceptual diagram schematically illustrating a nanodisk (300) of a metamaterial sensing platform (1) according to one embodiment of the present invention.

[0061] As illustrated in FIG. 4, a nanodisk (300) according to one embodiment of the present invention can be assembled by mixing G protein-coupled receptors (GPCR) (301) produced from E. coli cells and membrane support proteins (302) produced from E. coli cells.

[0062] These nanodisks (300) can have high stability when applied to biosensors because they are formed in a structure in which GPCR (301) is reconstituted in a lipid membrane and the lipid membrane is tightly wrapped with a membrane support protein (302).

[0063] Meanwhile, in one embodiment of the present invention, receptors involved in depression were expressed and purified using an E. coli system, and MSP protein was introduced to maintain the nanodisk shape through inducing cell membrane reorganization and refolding to ensure structural stability of GPCR family receptors, which are cell membrane proteins.

[0064] Specifically, in one embodiment of the present invention, a nanodisc (300) including a GPCR can be manufactured by a) producing and purifying a GPCR in E. coli cells; b) producing and purifying a membrane support protein in E. coli cells; and c) mixing a lipid, a membrane support protein, and a GPCR in that order, stirring, and assembling the nanodisc.

[0065] In addition, the step of producing and purifying GPCR in E. coli cells may include a step of expressing GPCR in the form of an inclusion body within E. coli cells, lysing E. coli to release the expressed inclusion body protein outside the cell, mixing a surfactant or the like to dissociate the inclusion body protein, purifying it, and then reconstituting it in the form of a GPCR.

[0066] Meanwhile, any protein added to wrap the lipid-receptor complex can be used as the membrane support protein (302), and preferably, Membrane Scaffold Protein (MSP 1E3D1) can be used.

[0067] Additionally, the lipid may be one or a mixture of two or more selected from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-disteroyl-sn-glycero-3-phosphocholine (DSPC), La-phosphatidylcholine (HSPC), 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 1,2-dioleyl-sn-glycero-3-phosphocholine (DOPC).

[0068] It was confirmed that the nanodisk (300) according to one embodiment of the present invention has an active interaction with a low-molecular-weight substance, which is a sensing target particle, and, for example, has stability even in the gas phase, so that it can be easily introduced into various sensor platforms, and as a platform that mimics a cell membrane and receptor, it can increase the reactivity and affinity for the sensing target particle.

[0069] FIG. 5 is a chemical formula schematically showing an amine group (102) bonded to a SiO2 layer (101) of a metamaterial sensing platform (1) according to one embodiment of the present invention.

[0070] As illustrated in FIG. 5, in one embodiment of the present invention, by introducing an amine group (-NH2) through chemical surface treatment of the SiO2 surface where the slit (201) is located, the nanodisk (300) can be selectively attached only to the part where terahertz signal amplification occurs.

[0071] Specifically, in one embodiment of the present invention, by treating the inside of the slit (201) with APTES (3-Aminopropyltriethoxysilane), a substance that easily reacts with the SiO2 surface, to introduce an amine group, a bond can be created between the amine group (102) of the SiO2 (101) surface and the nanodisk (300) through an EDC / NHS reaction.

[0072] FIG. 6 schematically illustrates the intensity of an electric field focused at a slit (201) of a particle collection unit (200) using a metamaterial sensing platform (1) according to one embodiment of the present invention.

[0073] As shown in Fig. 6, the intensity of the electric field focused at the slit (201) using Au as a particle collecting part (200) was calculated through simulation using the metamaterial sensing platform (1) according to one embodiment of the present invention, and it was confirmed that the electric field was focused at a high density between Au layers with a thickness of 150 nm.

[0074] In addition, it was confirmed that the nanodisk (300) introduced into the slit (201) can be introduced at a height of about 30 nm from the SiO2 (101) surface, and by selectively positioning it within a hotspot where electric field amplification is maximized, the target particle can be detected with high sensitivity.

[0075] FIG. 7a and FIG. 7b are graphs showing the signal change rate detected using a metamaterial sensing platform (1) according to one embodiment of the present invention.

[0076] As illustrated in FIGS. 7a and 7b, a metamaterial sensing platform (1) according to one embodiment of the present invention can efficiently focus the electric field of terahertz waves and amplify the signal, thereby utilizing terahertz time-based spectroscopy technology.

[0077] Specifically, by outputting a terahertz pulse using a laser having a wavelength of 800 nm and projecting it onto a metamaterial sensing platform (1) according to an embodiment of the present invention, and then utilizing the reflected signal detected by the detector (22), it was confirmed that it could have high efficiency in terms of signal-to-noise ratio (SNR), and through this, it was possible to sensitively analyze the presence or absence of serotonin molecules, which are low-molecular-weight substances attached to nanodisks (300).

[0078] Fig. 8 is a graph showing the amplification ratio of a detection signal using a metamaterial sensing platform (1) according to one embodiment of the present invention.

[0079] As shown in Fig. 8, when a terahertz reflection signal was measured for a serotonin hormone biomarker using a metamaterial sensing platform (1) according to an embodiment of the present invention, the amplification of the signal by the sensing target biomarker was maximum at around 0.72 THz, and a high signal change rate was observed.

[0080] That is, by utilizing the characteristics of metamaterials that can modulate the target frequency, the signal of the captured sensing target particle (T) can be maximized, and based on this, it was confirmed that it is possible to capture and detect low-molecular-weight biomarkers.

[0081] By referring to the above description, those skilled in the art to which the present invention pertains will be able to understand that the present invention can be implemented in other specific forms without changing the technical idea or essential characteristics thereof.

[0082] Therefore, it should be understood that the embodiments described so far are exemplary in all respects and are not intended to limit the present invention to the embodiments described above, and the scope of the present invention is indicated by the claims described below rather than the detailed description described above, and all changes or modified forms derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A sensing unit that captures particles; and A terahertz sensor unit that senses the particle by irradiating terahertz electromagnetic waves onto the sensing unit; The above sensing unit, A base substrate, comprising a particle collecting unit formed with a plurality of slits for collecting particles and disposed on the base substrate, A metamaterial sensing platform characterized in that nanodisks that react with the particles are arranged in the plurality of slits.

2. In paragraph 1, The above base substrate is a Si layer, A metamaterial sensing platform characterized in that an SiO2 layer obtained by oxidizing the Si layer is additionally disposed between the Si layer and the particle collecting section.

3. In paragraph 2, A metamaterial sensing platform characterized in that the above nanodisk is attached to the SiO2 layer via an amine group.

4. In paragraph 3, A metamaterial sensing platform characterized in that the particle collecting part is a Au layer and the thickness of the Au layer is 150 nm.

5. In paragraph 3, A metamaterial sensing platform characterized in that the above nanodisks are arranged at a height of 30 nm or less from the SiO2 surface.

6. In paragraph 3, A metamaterial sensing platform characterized in that the above nanodisk comprises G protein-coupled receptors (GPCR).

7. In paragraph 6, The above nanodisk is, A metamaterial sensing platform characterized in that it is assembled by mixing the G protein-coupled receptor produced from E. coli cells and the membrane support protein produced from E. coli cells.

8. In paragraph 2, A metamaterial sensing platform characterized in that the plurality of slits are formed by etching the particle collecting part in a negative manner so that the surface of the SiO2 layer is exposed.

9. In paragraph 8, A metamaterial sensing platform characterized in that the above etching is performed by a photolithography method.

10. In paragraph 1 A metamaterial sensing platform characterized in that the terahertz sensor unit senses the particle by injecting the terahertz electromagnetic wave into the sensing unit and detecting the terahertz electromagnetic wave reflected from the sensing unit.

11. In paragraph 10, A metamaterial sensing platform characterized in that the particle is sensed by measuring the reflectivity and frequency shift between the terahertz electromagnetic wave incident on the sensing unit and the terahertz electromagnetic wave reflected from the sensing unit.

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