KR101300321B1 - Device for detecting sers active particles at a liquid-liquid interface - Google Patents

Abstract

PURPOSE: A device for detecting an analyte using surface-enhanced Raman scattering (SERS) active particles on the liquid-liquid interface is provided to improve the sensitivity of SERS by the orientation of active particles such as metal nano particles on the liquid-liquid interface. CONSTITUTION: A device for detecting an analyte using SERS active particles on the liquid-liquid interface includes a cylindrical tube. The cylindrical tube is utilized for detecting the existence or the concentration of the analyte using the arrangement of the SERS active nano particles on the hydrophilic liquid-lipophilic liquid interface. The width of the central portion of a body made of a transparent material is shorter than the length of the widest width on the upper or lower part of the central unit of the body. A ratio of the width of the central unit with respect to the length of the widest width is about 5:1 to 10:1.

Description

Device for detecting SERS active particles at a liquid-liquid interface

It relates to the field of analyzing materials using surface enhanced Raman spectroscopic active particles.

Detection of various molecules present in a cell is important in providing important identification and static information in system biology and new drug development by providing more accurate identification and static information in the cell through fingerprint information of the cell.

One known detection method includes various trace molecular detection and analysis systems using nano plasmon structures. Surface Plasmon refers to surface electromagnetic waves propagating along the interface between metal and dielectric. Such surface plasmons can be strengthened according to changes in the surface or structure of a metal, which can be applied to biological molecular analysis technology and optical device development.

Localized Surface Plasmon Resonance (LSPR), an example of surface plasmon, selectively absorbs the energy of incident light depending on the size and shape of the metal nanoparticles and the dispersion properties of the surrounding medium. Scattering phenomenon. This means that light energy is absorbed and converted by the surface plasmons, and the electric field formed on the surface of the metal nanoparticles is locally distorted and strengthened, which means that light can be controlled in a region smaller than the diffraction limit of the light, that is, nearfield. do.

Raman Spectroscopy, another example of surface plasmons, is a highly specific and sensitive method of detecting a substance using information about the molecular's vibrational frequencies. In particular, Surface Enhanced Raman Spectroscopy (SERS) is a phenomenon in which the Raman signal is greatly increased when there are molecules near the metal surface, and Raman scattering occurs when molecules are adsorbed on the surface of metal nanostructures such as gold and silver. The strength of the abruptly increased by more than 10 ⁶ ~ 10 ⁸ times. In combination with nanotechnology, it is possible to develop high-sensitivity technology that can directly measure a single molecule, and is expected to be used as a sensor for detecting biomaterials.

U.S. Pat.No.7929133 relates to a nanostructure sensing device for use in SERS, and discloses a device comprising a nanosurface having activity on SERS and an adsorption surface inert to SERS present on the surface.

However, in order to detect a substance in this way, the synthesis of nanoparticles having a complex micro-oil system or a complex structure must be preceded. However, the manufacturing process is complicated and difficult, so it is difficult to be practical. In addition, the detection of intracellular polymers, particularly polymers, such as proteins and nucleic acids that form a three-dimensional structure in solution, is present in a very small amount, and the detection sensitivity is very low due to the Brownian motion in the solution. There is a problem that the detection takes a long time to be laid.

Therefore, there is a need to develop a method and a device suitable for detecting a biological material present in trace amounts directly in a solution without the use of such a complex structure or synthesis of nanoparticles.

The present invention has been made to solve the above problems, and to provide an optical molecular detection system with improved sensitivity of SERS through the orientation of SERS active particles, such as metal nanoparticles at the liquid-liquid interface.

The present application is a circular tube used to detect the presence or concentration of analytes using an array of SERS active nanoparticles at a hydrophilic liquid-lipophilic liquid interface, wherein the width of the center of the body of transparent material is above or below the center of the body. A tube for SERS is provided that is smaller than the length of the widest portion of the portion and the ratio of the length of the widest width to the length of the central portion width is 5: 1 to 10: 1.

The present application also discloses that the SERS active nanoparticles used in the analysis using the SER tubes of the present disclosure are metals, which metals are composed of Ag, Au, Cu, Pt, Al, Fe, Co, Ni, Ru, Rh, and Pd. Provided are tubes for SERS, selected from the group.

The present application also provides a tube for SERS, wherein the metal used in the analysis using the SER tube of the present application is a nanorod, wherein the metal nanorod is arranged perpendicular to the hydrophilic liquid-lipophilic liquid interface.

The present application also provides a tube for SERS, wherein the aspect ratio of the metal nanorods used in the analysis using the SER tube of the present disclosure is from 1: 0.1 to 1:10.

The present application also provides a tube for SERS, wherein the length of the metal nanorods used in the analysis using the SER tube of the present disclosure is 1 nm to 500 nm.

The present application also provides a tube for SERS, wherein the analyte used in the assay using the SER tube of the present application is a biomolecule included in a biological sample, which is a carbohydrate, DNA, RNA or protein.

The present application is also an analyte detection kit using surface enhanced Raman spectroscopy, comprising a tube for SERS according to the present application, the kit comprising a hydrophilic or lipophilic SERS active nanoparticle dispersion and optionally a hydrophilic or lipophilic material , The lipophilic or hydrophilic material is added to the dispersion to form a hydrophilic-lipophilic liquid interface, provides a kit for analyte detection using surface enhanced Raman spectroscopy.

The method in which the device of the present invention is used is characterized by the fact that the specific analyte having amphiphilic characteristics increases the sensitivity at the liquid interface and thus the sensitivity is further increased to form a three-dimensional structure in a biological polymer material, especially a solution, which is present in trace amounts in the sample. It is particularly useful for the detection of substances with low detection sensitivity due to exercise, and is a significant improvement compared to the existing ones in which such substances can be detected without a separate label, and are optimized for the detection of analytes through this method.

Figure 1 is a schematic diagram showing the presence or concentration detection process of the analyte using the arrangement of SERS active nanoparticles at the hydrophilic liquid-lipophilic liquid interface using the device of the present application.
2A is a perspective view of an apparatus according to an embodiment of the present disclosure.
2B is a front view of the apparatus according to one embodiment of the present application.
2C is a plan view of an apparatus according to an embodiment of the present disclosure.

In one aspect, the present disclosure is directed to a circular tube used for detecting the presence or concentration of an analyte using an array of SERS active nanoparticles at a hydrophilic liquid-lipophilic liquid interface.

The method in which the apparatus of the present invention is used relates to a novel method for measuring surface enhanced Raman scattering in a liquid state, wherein surface enhanced Raman scattering active nanoparticles in a liquid state have a specific arrangement on the interface through liquid-liquid interface energy control. It is based on the finding that SERS can be measured in the liquid state. Alternatively, in the case of amphiphiles, the analyte can be concentrated at the interface to obtain a stronger surface enhanced Raman scattering signal.

An example of the use of the device herein used in this method is shown in FIG. 1. The apparatus of the present invention is composed of a body of transparent material, the width of the center portion of the body is less than the length of the widest width of the upper or lower portion of the center portion of the body, the width of the widest length versus the width of the center portion The ratio of the lengths is about 5: 1 to 10: 1, and may be configured as shown in FIGS. 2A to 2C, for example.

Since the structure is proportional to the square of the diameter, the number of molecules may be pre-concentrated relative to the area, which is advantageous for the measurement of biological samples such as proteins having a small amount in the cell.

The device of the present invention may be made of a material that can pass through the light, including the laser. For example, a transparent plastic material or glass may be used, and the former may include, but is not limited to, for example, polymethylmethacrylate (PMMA) and polyethylene (PE).

Referring to the method that can be used as the apparatus of the present application as follows.

Surface Enhanced Raman Scattering, or SERS, is a Raman scattering signal or intensity where Raman active molecules (analytes) are located close to, for example, about 50 microseconds from the metal surface, or adsorbed on the metal surface. It refers to the phenomenon that the scattering signal is increased. Surface Enhnaced Resonance Raman Scattering or SERRS is an increased SERS signal that occurs when reporter molecules located close to the surface of SERS-activated nanoparticles generate excitation wavelengths and resonances.

As used herein, SERS active particles refer to particles that can induce or cause SERS or SERRS, the surface of the active particles being capable of producing SERS signals, e.g. rough surfaces, smooth surfaces, surfaces with specific textures, etc. It is to include.

The SERS active particles herein refer to SERS active nanoparticles in particular and have at least one dimension of about 1 nm to about 100 nm (one dimension in size).

Nanorods can be produced, for example, by a variety of known methods, have a specific aspect ratio, and length refers to, for example, a portion parallel to the aperture in which nanoparticles are produced. Nanorods of various aspect ratios may be used herein and may vary depending on the type of specific material to be detected. Aspect ratios that can be used herein are from 1: 0.1 to 1:10. In one embodiment, 1: 3.5.

The nanorods can also be expressed in length, in one embodiment the nanoparticles are about 10 nm to 500 nm in length. Once the length is set, the aspect ratio also determines the width. In one embodiment, the aspect ratio of the nanorod particles is 3.7, in which case the length is 59 nm and the width is 16 nm.

SERS active nanoparticles that can be used herein include one or more metals, for example metals on the periodic table. For example, suitable metals include metals of Group 11 such as Cu, Ag, and Au and SERS-derived metals known in the art, such as alkali metals. For example, the types of metals that may be used herein include, but are not limited to, Ag, Au, Cu, Pt, Al, Fe, Co, Ni, Ru, Rh, and Pd.

In one embodiment the metal is gold and Gold Nanoparticles, in particular Gold Nano Rods (GNR), are used. Metals that may be used herein may also be used as alloys in which a single or two or more metals are combined. Methods of making metal nanoparticles are known in the art, for example Frens, G., Nat. Phys. Sci., 241, 20 (1972) or ou, L., and Murphy, C. J. Fine-Tuning the Shape of Gold w Nanorods. Chem. Mater. Reference may be made to 17 (14), pp 36683672 (2005).

SERS active nanoparticles are affected by physical, optical and electronic properties depending on their shape and aspect ratio, and nanoparticles of various shapes and aspect ratios can be used herein as long as the effects of the present application are exhibited. Shapes of nanoparticles that can be used herein include, but are not limited to, various mechanical and non-mechanical shapes such as spheroids, rods, disks, pyramids, cubes, cylinders. In one embodiment of the present application, rod-shaped nanoparticles are used. Alternatively, not only rod particles, but also other shapes, may have a specific orientation on the interface, and particles of various shapes and aspect ratios may be used if a laser having a wavelength corresponding thereto is used.

As mentioned above, the present application is to detect analytes present in trace amounts by amplifying SERS intensity by causing the SERS active nanoparticles to take a specific orientation, through interfacial energy control at the hydrophilic-lipophilic interface. At this time, the hydrophilic material of the present application includes various solvents in which the SERS active nanoparticles can be dispersed, for example, water, or an organic solvent including ethanol and methanol, but is not limited thereto. In addition, when the analyte is included in the lipophilic substance, it is also possible to detect the analyte by adding the hydrophilic substance to the SERS active nanoparticles to orient the interface. Dispersion characteristics of SERS active particles depend on the stabilizing material on the surface of the particles, and as reported so far, SERS active particles can be dispersed in a hydrophilic solvent or a lipophilic solvent depending on the type.

The lipophilic material does not mix with the hydrophilic material, and various materials capable of forming an interface may be used. Water-insoluble substances, for example fatty acids, such as unsaturated and saturated fatty acids, such as unsaturated fatty acids, myristoleic acid, pilmitoleic acid, sapienoic acid, oleic acid, oleic acid, bacenic acid, linoleic acid, linolenic acid, arachidonic acid Deicosapentaic acid, erucic acid, docosahexaenoic acid, or saturated fatty acid as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, Include but are not limited to lignoseric acid and sertric acid.

When lipophilic material is added to a hydrophilic solution containing analyte, for example, an aqueous solution, SERS-activated nanoparticles such as gold nanorod particles are added and lipophilic substances such as oleic acid are added. An interface is formed and the GNR is oriented vertically with the lowest energy at that interface.

The method described above can be used for detection, such as determination of the presence or concentration of analytes using SERS in the liquid phase, using the apparatus of the present application.

Analytes that can be used in the devices herein by the methods described above include a variety of low molecular and polymeric compounds, especially present in trace amounts, for example taking a three-dimensional structure in biological polymers, in particular in solution, due to Brownian motion It includes substances with low detection sensitivity. Examples include, for example, single or double stranded DNA (Deoxyirbonucleic acids) or RNAs (Ribonucleic acids), including carbohydrates, oligonucleotides and polynucleotides, including monosaccharides and polysaccharides, and oligopeptides, polypeptides and proteins. It includes, but is not limited to, includes modified forms in which other compounds are bound to the material.

In one embodiment herein, the analyte is an amphipathic substance. In the case of amphiphilic materials, the diffusion coefficient difference between the lipophilic solvent and the hydrophilic solvent at the lipophilic-hydrophilic liquid interface in which the metal nanoparticles are arranged may have the effect of concentration of the analyte at the interface, thereby obtaining a stronger SERS signal. have. Amphiphiles are molecules having both hydrophobic and hydrophilic groups, for example polyethylene glycol, polyvinylpyrrolidone, flulon F68, and the like. Such materials are widely used for protein modifications to regulate efficacy or to be applied to drug delivery systems, and the present invention can be readily used for the detection of such materials.

In one embodiment of the present application, a laser may be used as excitation light for Raman signal generation. Those skilled in the art will be able to select an appropriate laser intensity and wavelength that will produce the effects of the present application. To achieve the SERS effect, the nanoparticles are excited using an excitation laser, in which case the wavelengths that cause resonance with the nanoparticles depend on the shape, size and / or material of the nanoparticles. Therefore, instead of using a laser limited to a specific wavelength, a laser having a wavelength that can resonate with the nanoparticles used should be employed, and a person skilled in the art will be able to select an appropriate wavelength. For example, the excitation wavelength may vary depending on the aspect ratio of the GNR used, and when the aspect ratio is 1: 3.7, a laser of 785 nm may be used.

In order to show the effect of the present invention, the irradiated laser has an important polarization angle and irradiation direction. When the laser is irradiated in parallel with the liquid-liquid interface, the SERS signal is maximum when the polarization angle of the laser is 90 degrees. This is because they are arranged vertically at the liquid-liquid interface. In one embodiment of the present application the laser is irradiated in parallel with respect to the liquid-liquid interface and the polarization angle is 90 degrees.

In one embodiment, the methods herein can also be performed directly in the sample comprising the analyte without additional treatment. For example, a sample can be collected in a test vessel, added SERS-activated nanoparticles and a hydrophilic substance to it, and then the Raman signal generated by laser irradiation of a specific wavelength can be read by a detector.

The addition of oleic acid, an insoluble solvent herein, to the SERS active nanoparticle dispersion results in a change of interfacial energy of the solution. As a result, the GNR at the hydrophilic-lipophilic interface has the lowest energy direction, i.e. The long axis of the GNR is perpendicular to the interface (see FIG. 1A), which results in amplification of the SERS signal strength.

In one embodiment of the present application, the theoretical arrangement and experimentally verified the vertical arrangement of GNR, a goldnadorod, using water and oleic acid as hydrophilic and lipophilic materials, as SERS active nanoparticles at the oleic acid-water interface, It has been demonstrated that specific orientation can be used to detect target molecules using SERS in the liquid state.

Such detection methods herein can (i) determine the location and orientation of SERS-activated nanoparticles such as GNR, thereby improving reproducibility and (ii) direct liquid phase without additional steps such as post-treatment of nanoparticles prior to SERS signal detection. Provides the convenience of collecting SERS signals from

The application also provides a kit for detecting analytes using surface enhanced Raman spectroscopy, comprising the device of the present disclosure, which kit comprises a hydrophilic or lipophilic SERS active nanoparticle dispersion and optionally hydrophilic or lipophilic as described herein above. Contains an oily substance. The lipophilic or hydrophilic material is added to the dispersion so that a hydrophilic-lipophilic liquid interface can be formed, that is, the dispersion of SERS-activated nanoparticles in the kit includes a lipophilic material, SERS-activated nano When the dispersion of particles is lipophilic, it includes a hydrophilic substance. The kits herein can be used for detection of analytes in various devices in which the methods herein can be implemented.

In summary, the present invention relates to a new method of measuring SERS in the liquid state. By controlling the interfacial energy, the arrangement of the GNR in the liquid state was controlled. Upon addition of oleic acid, the GNR takes a vertical arrangement with the lowest energy at the interface.

 Theoretical calculations and experiments have demonstrated the vertical arrangement of the GNR at the interface. As a result of applying this property to molecular detection using SERS, 10nM R6G detection was possible without additional treatment for GNR. The present invention opens a new chapter in molecular detection and may be widely used in basic and applied sciences.

Claims (7)

A circular tube for the presence or concentration detection of analytes using an array of SERS active nanoparticles at a hydrophilic liquid-lipophilic liquid interface,
The width of the central portion of the body of transparent material is smaller than the length of the widest width of the upper or lower portion of the central portion of the body, and the ratio of the length of the widest width to the length of the central portion is 5: 1 to 10. : 1 tube for SERS.
The method of claim 1, wherein the SERS active nanoparticles are metals, and the metals are selected from the group consisting of Ag, Au, Cu, Pt, Al, Fe, Co, Ni, Ru, Rh, and Pd. tube.
The tube of claim 2, wherein the metal is a nanorod, and the metal nanorods are arranged perpendicular to the hydrophilic liquid-lipophilic liquid interface.
4. The tube for SERS according to claim 3, wherein the aspect ratio of the rod is from 1: 0.1 to 1:10.
The tube for SERS according to claim 3, wherein the metal nanorods have a length of 1 nm to 500 nm.
The tube of claim 1, wherein the analyte is a biomolecule included in a biological sample, and is carbohydrate, DNA, RNA or protein.
An analyte detection kit using surface enhanced Raman spectroscopy, comprising a tube for SERS according to any one of claims 1 to 6, said kit comprising a hydrophilic or lipophilic SERS active nanoparticle dispersion and optionally hydrophilic Or a lipophilic material, wherein the lipophilic or hydrophilic material is added to the dispersion to form a hydrophilic-lipophilic liquid interface, kit for analyte detection using surface enhanced Raman spectroscopy.

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