KR20120035749A - Simultaneous measuring sensor system of lspr and sers signal based on optical fiber - Google Patents

Abstract

PURPOSE: A simultaneous measuring sensor system of LSPR(Localized Surface Plasmon Resonance) and SERS(Surface Enhanced Raman Scattering) signals based on optical fibers is provided to simultaneously measure a plurality of target materials with an easy method by using a plurality of optical fibers and forming different kinds of marking substances on each optical fiber. CONSTITUTION: A simultaneous measuring sensor system(100) of LSPR and SERS signals based on optical fibers comprises a sensor(110), a light source(120), an optical wave guide(130), an optical filter(140), and a measuring part(150). The sensor comprises one or more optical fibers(170,180,190) having metal nano particles(172,182,192) in the endmost portion. The light source supplies one colored incident light with respect to the sensor. The optical wave guide transmits lights between the sensor and light source. The optical filter receives output light emitted from the sensor, thereby reflecting some of the output light. The optical filter passes through the rest of the output light so that the output light is separated. The measuring part respectively collects the some part and the rest part of the separated output light.

Description

Simultaneous measuring sensor system of LSPR and SERS signal based on optical fiber

The present invention relates generally to optical fiber based sensor systems, and more particularly to sensor systems for measuring LSPR and SERS signals based on optical fibers.

Recently, researches for detecting and analyzing biotargeting materials such as biochips have been actively conducted. In the conventional case, as the detection method of the biotarget material, electrophoresis, mass spectrometry, fluorescence analysis, etc. were used, but each analysis method had disadvantages. That is, in the case of electrophoresis, there is a relatively poor reproducibility and it is difficult to separate the alkaline protein and the polymer protein, and in the case of mass spectrometry, it is difficult to miniaturize and to analyze a large number of samples quickly. In the case of the fluorescence method, it is inconvenient to label all biological materials with fluorescent materials, and there is a difficulty in that the price of fluorescent dyes is high.

Therefore, Raman Scattering and Surface Plasmon Resonance, which use spectroscopic techniques as an alternative to the above-described analytical methods, have attracted attention from academics and the industry. In particular, one of the Raman scattering methods, Surface Enhanced Raman Scattering (SERS) and Localized Surface Plasmon Resonance (LSPR), which is one of the surface plasmon resonance methods, is a biotarget material. It is actively attempted to apply to biochips that detect.

The Raman scattering method refers to a method of irradiating a molecule with light of energy larger than the vibration energy of the molecule and observing scattered light thereto. By interacting with the molecule when light of energy greater than the vibrational energy of the molecule is irradiated, the scattered light is lost or obtained by molecular vibrational energy than the incident light. This is possible because the vibrational energy of the molecule is inherent. SERS refers to a phenomenon in which the Raman signal of the molecule is greatly increased when the molecule is in the vicinity of the metal nanostructure. Since the discovery of this SERS, it has been applied to various material detection methods. Korean Laid-Open Patent Publication No. 2006-0094521 discloses a method and system for nucleic acid sequencing by increasing nucleotide signals by surface enhanced Raman spectroscopy. In addition, Korean Patent Publication No. 2006-0056579 discloses a method of adsorbing a DNA mixture to silver nanoparticles and optically detecting the DNA by applying the SERS method.

Meanwhile, in the surface plasmon resonance method, the surface plasmon means surface electromagnetic waves traveling along the interface between the metal thin film and the dielectric, and the surface plasmon resonance phenomenon is a quantization of the collective vibration of electrons occurring on the metal thin film surface. And the phenomenon that surface plasmon is excited is called surface plasmon resonance. Surface plasmon resonance can measure the interaction between molecules or measure the progress of a reaction in real time using the optical principle described above. LSPR, a field of surface plasmon resonance, means that electrons are constrained to metal nanoparticles, causing collective vibration. LSPR has the characteristics that the surface plasmon absorption band intensity or wavelength varies depending on the type of metal nanoparticles, and the surface plasmon wavelength varies depending on which material the metal nanoparticles are placed in. The metal herein refers to precious metals such as gold, silver and the like having surface plasmid resonance conditions in the visible region. In addition, the surface plasmon wavelength is known to vary depending on the size, shape, and distribution of the metal nanoparticles. Korean Patent Laid-Open Publication No. 2009-0087574 discloses a method of generating an antigen-antibody reaction after immobilizing gold nanoparticles on a glass plate and diagnosing a biomaterial using LSPR.

As described above, the SERS or LSPR method has been actively adopted in the biosensor for detecting the biomarker, the industry interest in this is increasing trend.

Disclosed is an optical fiber based sensor system according to an aspect of the present application for achieving the above technical problem. The optical fiber-based sensor system includes a sensor unit including at least one optical fiber in which metal nanoparticles are disposed at one end of a cross-section, a light source providing monochromatic incident light to the sensor unit, and a light between the sensor unit and the light source. An optical waveguide for transmitting an optical filter for receiving an output light reacted with the metal nanoparticles in the sensor unit, reflecting a part of the output light and passing the remaining part of the output light to separate the output light. ; And a measuring unit for converging the portion and the remaining portion of the separated output light, respectively.

Disclosed is an optical signal measuring method using an optical fiber based sensor system according to another aspect of the present application for achieving the above technical problem. In the optical signal measuring method using the optical fiber based sensor system, first, a sensor unit having at least one optical fiber having metal nanoparticles disposed on one end of the optical fiber is prepared. Monochromatic incident light is provided to the sensor unit. The remaining portion converging the output light reacted with the metal nanoparticle in the sensor unit, reflecting the portion of the output light corresponding to the center wavelength of the incident light by an optical filter, and excluding the center wavelength of the incident light Pass it through. The portion of the output light corresponding to the center wavelength converges through a photo detector, and the remaining portion excluding the center wavelength converges through a spectrometer.

According to an embodiment of the present application, by providing a sensor system of the SERS and LSPR signal, it is possible to simultaneously implement the SERS method capable of multi-target simultaneous measurement with a single molecule signal sensitivity and the LSPR method capable of real-time quantification with high signal sensitivity have. As a result, multiple real-time quantitative measurement platform technology for biological target materials can be implemented.

According to one embodiment of the present application, it is possible to implement a small, simple, low-cost measurement system by employing an optical fiber, and simultaneously using a plurality of optical fibers and to form a different labeling material on each optical fiber to simultaneously target a plurality of target materials Quantitative techniques can be implemented in an easy way.

1 is a view schematically showing an optical fiber based sensor system according to an embodiment of the present application.
2 is a cross-sectional view of an optical fiber that is a sensor unit of an optical fiber based sensor system according to an exemplary embodiment of the present application.
3 is a flowchart illustrating an optical signal measuring method using an optical fiber based sensor system according to an exemplary embodiment of the present application.
4 is a diagram schematically illustrating a measurement method of an optical fiber based sensor system according to an exemplary embodiment of the present application.

Embodiments of the present application will now be described in more detail with reference to the accompanying drawings. However, the techniques disclosed in this application are not limited to the embodiments described herein but may be embodied in other forms. It should be understood, however, that the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the width, thickness, and the like of the components are enlarged in order to clearly express the components of each device. The description was made at the point of view of the observer as a whole, and one of ordinary skill in the art may realize the spirit of the present application in various other forms without departing from the technical spirit of the present application. In addition, in the drawings, the same reference numerals refer to substantially the same elements.

In addition, singular expressions should be understood to include plural expressions unless the context clearly indicates otherwise, and the terms “comprise” or “having” should include features, numbers, steps, actions, components, and parts described. Or combinations thereof, it is to be understood that they do not preclude the presence or addition of one or more other features or numbers, steps, operations, components, parts or combinations thereof.

Further, the attachment of the first component to the second component means that the first component is attached directly to the second component, as well as the second component via or using the third component. When attached to an element, it is interpreted to include all.

1 is a view schematically showing an optical fiber based sensor system according to an embodiment of the present application. In detail, (a) of FIG. 1 is a schematic diagram of a sensor system based on an optical fiber according to an embodiment, and FIG. 1 (b) illustrates a sensor unit of the sensor system of FIG. 1 (a) according to an embodiment. It is a schematic diagram in detail. 1C is a cross-sectional view of a sensor unit of a sensor system according to an embodiment. Referring to FIG. 1A, the sensor 100 system includes light between a sensor unit 110, a light source 120 that provides incident light to the sensor unit 110, a sensor unit 110, and a light source 120. It includes an optical waveguide 130 for transmitting the light and the optical filter 140 for separating the output light from the sensor unit 110 and the measuring unit 150 for converging the separated output light, respectively. In some embodiments, the sensor system 100 further includes an optical coupler 160 for guiding the output light from the sensor unit 110 to the optical filter 140 and a lens unit 162 for focusing the output light. It may include.

The sensor unit 110 includes at least one optical fiber in which metal nanoparticles are disposed in a cross section of one end thereof. Referring to FIGS. 1B and 1C, the sensor unit 110 includes at least one optical fiber 170, 180, 190, and at least one end of at least one optical fiber 170, 180, 190. The cross section is exposed to the external environment in which the target materials 176, 186, 196 are present. Each of the at least one optical fiber 170, 180, 190 includes metal nanoparticles 172, 182, 192, labeling materials 174, 184, 194 attached to the metal nanoparticles 172, 182, 192, and The labeling materials 174, 184, and 194 are attached to predetermined target materials 176, 186, and 196, such that the sensor unit 110 may detect the predetermined target materials 176, 186, and 196. . The sensor unit 110 detects the target materials 176, 186, and 196 by emitting different optical signals in the form of output light depending on whether the target materials 176, 186, and 196 are attached. In an embodiment, the sensor unit 110 includes a plurality of optical fibers 170, 180, and 190, and the plurality of optical fibers 170, 180, and 190 may include a plurality of metal nanoparticles 172 on which different labeling materials are formed. , 182 and 192 may be provided.

The light source 120 provides monochromatic incident light to the sensor unit 110. As an example, the light source 120 may be laser light, and various light having a narrow wavelength width of light may be applied based on the center wavelength. Here, the center wavelength may refer to a wavelength for determining the color of the incident light in monochromatic incident light. For example, in the case of an Ar laser, laser light of green light having a center wavelength of 514.5 nm or laser light of green light having a center wavelength of 532 nm in the case of an Nd: YAG laser, wherein the green light of the lasers is the center wavelength. The left and right widths from are within 0.5 nm. In addition, laser light having various center wavelengths in the visible light region may be used depending on the purpose.

In one embodiment, when incident light corresponding to the center wavelength λ ₀ is incident on the sensor unit 110, the sensor unit 110 may be formed from the metal nanoparticles 172, 182, and 192 exposed to a target material in an external environment. Can be emitted in the form of output light. As described above, the target material of the external environment is attached to the metal nanoparticles 172, 182, and 192 through the labeling materials 174, 184, and 194. The reflected output light may reflect the result of absorption and scattering of the incident light through reaction with the metal nanoparticles 172, 182, and 192, and may have a center wavelength component λ ₁ corresponding to the center wavelength λ ₀ . . Through measurement, as an example, LSPR signal analysis can be performed through a change from the central wavelength λ ₀ to λ ₁ . In LSPR signal analysis, the shift and intensity change of the center wavelength λ ₀ of the incident light are varied depending on whether the target material 174, 184, 194 is attached to the metal nanoparticles 172, 182, and 192. The output light is shown.

In addition, the reflected output light includes scattered light components from the optical fibers 170, 180, and 190, wherein the scattered light components include target materials 174, 184, and 194 attached to the optical fibers 170, 180, and 190. The interaction of the incident light may be reflected. The incident light may react with the target materials 174, 184, and 194, so that scattered light may be generated as a result of a reaction of obtaining or losing energy from the vibration energy of the target materials 174, 184, and 194. That is, the scattered light generates a change in the SERS signal depending on whether the target materials 174, 184, and 194 are attached.

The optical waveguide 130 serves to transmit light between the sensor unit 110 and the light source 120. The optical waveguide 130 may be, for example, an optical fiber. Referring to FIG. 1, light emitted from the light source 120 is incident on the sensor unit 110 through the optical waveguide 130, and output light emitted from the sensor unit 110 is transmitted through the optical waveguide 130. Can be guided to coupler 160. The optocoupler 160 may converge the output light and transfer it to the optical filter 140.

The optical filter 140 receives the output light emitted from the sensor unit 110 to reflect a portion of the output light, and separates the output light by passing the remaining portion of the output light. According to an embodiment, the optical filter 140 reflects the center wavelength component λ ₁ in the output light corresponding to the center wavelength λ ₀ of the incident light, and outputs the output corresponding to the center wavelength λ ₀ of the incident light. The remaining components except for the central wavelength component λ ₁ of light can pass through. According to an exemplary embodiment, an edge filter or notch for Raman scattering spectroscopy having a steep cut-off edge and a very high permeability / reflection ratio may be used to effectively obtain a signal such as a Raman scattered light having a very narrow line width. Notch) filter may be applied as the optical filter 140. The central wavelength component λ 1 in the output light may be generated by reaction with the metal nanoparticles 172, 182, and 192. The light component except for the central wavelength component λ ₁ of the output light may be a scattered light component generated through reaction with target materials 176, 186, and 196 attached to the metal nanoparticles 172, 182, and 192. The central wavelength component λ ₁ of the reflected output light is applied to LSPR analysis, and the scattered light component of the passed output light can be applied to SERS analysis.

For example, the measurement unit 150 may include a photodetector 152 and a spectrometer 154. Photodetector 152 converges the portion of the output light that is reflected by optical filter 140. Specifically, the photodetector 152 converges the central wavelength component λ ₁ of the output light reflected by the optical filter 140. The central wavelength component λ ₁ of the output light converging at photodetector 152 may be applied to LSPR quantitative analysis.

The spectrometer 154 converges the remaining components excluding the central wavelength component λ ₁ of the output light passing through the optical filter 140. Specifically, the spectrometer 154 converges the scattered light component of the output light passing through the optical filter 140. The remaining components of the output light converging in the spectrometer 154 may be applied to SERS qualitative analysis.

As described above, in the optical fiber-based sensor system according to an embodiment of the present application, the central wavelength component λ ₁ of the output light corresponding to the center wavelength of the incident light is reflected by the optical filter, and is detected by the photo detector to detect the center. The intensity of the output light having the wavelength component λ ₁ can be measured. In addition, it is possible to quantitatively grasp the reaction with the target material on the surface of the optical fiber in the sensor unit through the change in the light intensity (the intensity of λ ₁ compared to λ ₀ ) at the central wavelength of the output light versus the incident light indicated by the LSPR measurement result. On the other hand, the scattered light component except for the central wavelength component λ ₁ of the output light can be measured in the spectrometer by passing through the optical filter. Through the wavelength change of the scattered light component indicated by the SERS measurement result, it is possible to qualitatively grasp the reaction with the target material on the surface of the optical fiber of the sensor unit. As such, according to the optical fiber based sensor system according to the exemplary embodiment of the present application, LSPR measurement and SERS measurement on a reaction occurring on the optical fiber surface of the sensor unit may be simultaneously performed through a single light source. In addition, different labeling materials may be formed on a plurality of optical fibers to simultaneously measure multiple target materials in a measurement sample.

As shown in FIG. 1, an optical fiber based sensor system according to an embodiment of the present application has a sensor unit 110 including a plurality of optical fibers 170, 180, and 190, and the sensor unit 110 is a single unit. The optical waveguide 130, the lens unit 162, the optical filter 140 and the measuring unit 150 of the. According to some embodiments, the sensor system of the optical fiber substrate may include at least two optical waveguides, a lens unit, an optical filter, and a measurement unit corresponding to the optical fibers 170, 180, and 190. As an example, the number of optical waveguides, lens units, optical filters, and measurement units equal to the number of optical fibers 170, 180, and 190 may be provided. As a result, different target substances may be separately detected for each of the plurality of optical fibers 170, 180, 190 of the sensor unit 110.

2 is a cross-sectional view of an optical fiber that is a sensor unit of an optical fiber based sensor system according to an exemplary embodiment of the present application. FIG. 2A is a scanning electron micrograph of a cross-sectional view of the optical fiber, and FIG. 2B is a magnified photo of FIG. Referring to FIGS. 2A and 2B, a plurality of metal nanoparticles may be dispersed and disposed on a cross section of an optical fiber that is a sensor unit. Specifically, the metal nanoparticles are gold nanoparticles, and as shown, may be disposed on a cut surface of the optical fiber with a diameter of about 50 nm. Also in other embodiments, the nanoparticles are not absolute in size and may be from several nm to one hundred nanometers or more, depending on the purpose. As described above, a plurality of labeling substances may be attached onto the gold nano-entrance to be applied to detection of the target substance.

3 is a flowchart illustrating an optical signal measuring method using an optical fiber based sensor system according to an exemplary embodiment of the present application. Referring to FIG. 3, first, at 310 block, a sensor unit including at least one optical fiber having metal nanoparticles disposed at one end thereof is prepared. The sensor unit includes at least one optical fiber, each of which includes metal nanoparticles, a label material attached to the metal nanoparticles, and a target material attached to the label material. The sensor unit emits different optical signals in the form of output light depending on whether the target material is attached, thereby detecting the target material.

In block 320, a monochromatic incident light is provided to the sensor unit. The monochromatic incident light may be, for example, laser light, and light of various wavelengths having a narrow wavelength width of light with respect to a center wavelength may be applied.

In block 330, the output light emitted from the sensor unit converges and reflects a portion of the output light corresponding to the center wavelength of the incident light by an optical filter and passes the remaining portion excluding the center wavelength of the incident light. Specifically, the center wavelength component λ ₁ of the output light corresponding to the center wavelength λ ₀ of the incident light is a component reacted with the metal nanoparticles of the incident light, and the remaining portion of the output light except for the center wavelength component λ ₁ of the output light. May be a Raman scattered light component.

In block 340, a portion of the output light corresponding to the center wavelength is converged through a photo detector, and a remaining portion of the output light excluding the center wavelength is converged through a spectrometer. The portion of the output light converging in the photodetector may be applied for LSPR quantitative analysis, and the remaining portion of the output light converging in the spectrometer may be applied for SERS qualitative analysis.

4 is a diagram schematically illustrating a measurement method of an optical fiber based sensor system according to an exemplary embodiment of the present application. In FIG. 4A, incident light whose central wavelength having a predetermined intensity (Y-axis value) is λ ₀ is shown. 4B illustrates output light emitted from the sensor unit. For example, the output light may have a component corresponding to the center wavelength λ ₀ of the incident light and having a center wavelength λ ₁ . The output light may separately include a component having a wavelength of λ ₂ to λ ₄ , which means a Raman scattered light component. As illustrated, λ ₂ , λ ₃ , and λ ₄ may represent, for example, SERS labeling spectra corresponding to three different target substances, and in reality, a spectrum consisting of several bands, not one band, is distinguished from each other. Means. In (c) of FIG. 4, the central wavelength component and the scattered light component are separated from the output light through an optical filter. In FIG. 4C, the scattered light component passing through the optical filter is illustrated, and in FIG. 4C-2, the central wavelength component reflected by the optical filter is schematically illustrated. In FIG.4 (d), the example which uses the said center wavelength component and the said scattered light component isolate | separated from the said output light is represented typically. 4 (d-1) shows an example used for SERS analysis. In the SERS analysis, quantitative analysis is performed to analyze the appearance of the target substance and the components of the target substance. That is, the wavelength shift and intensity change of the scattered light component having a wavelength of λ ₂ to λ ₄ are analyzed. 4 (d-2) shows an example used for LSPR analysis. In the LSPR analysis, a change in the surface plasmon resonance angle and a change in the intensity of reflected light according to the target material can be analyzed in the sensor unit. In addition, the above-described surface plasmon resonance angle change can be observed as a change with time, which can be shown in the form of a sensogram in FIG. In the sensogram, a phenomenon in which the target material is adsorbed and desorbed on the metal nanoparticles in the optical fiber, which is a sensor, may be detected in real time. LSPR analysis and SERS analysis methods and techniques described herein are well known to those skilled in the art corresponding to known analysis methods, and thus detailed descriptions thereof will be omitted.

As described above, in the optical fiber based sensor system according to the exemplary embodiment of the present application, the central wavelength component λ ₁ of the output light corresponding to the center wavelength of the incident light is reflected by the optical filter, and is detected by the photo detector, thereby detecting the reflected light. Intensity can be measured. In addition, it is possible to quantitatively grasp the reaction with the target material on the optical fiber surface of the sensor unit through the light intensity change (the intensity of λ ₁ compared to λ ₀ ) at the central wavelength of the output light versus the incident light indicated by the LSPR measurement result. On the other hand, the scattered light component except for the central wavelength component λ ₁ of the output light can be measured in the spectrometer by passing through the optical filter. Through the wavelength change of the scattered light component indicated by the SERS measurement result, it is possible to qualitatively grasp the reaction with the target material on the surface of the optical fiber of the sensor unit. As such, according to the optical fiber based sensor system according to the exemplary embodiment of the present application, LSPR measurement and SERS measurement on a reaction occurring on the optical fiber surface of the sensor unit may be simultaneously performed through a single light source. In addition, different labeling materials may be formed on a plurality of optical fibers to simultaneously measure multiple target materials in a measurement sample.

100: optical fiber based sensor system, 110: sensor unit, 120: light source, 130: optical waveguide, 140: optical filter, 150: measuring unit, 152: photodetector, 154: spectrometer, 170 180 190: optical fiber, 172 182 192 : Metal nanoparticles, 174 184 194: labeling substance, 176 186 196: target substance.

Claims (11)

In the optical fiber based sensor system,
A sensor unit including at least one optical fiber in which metal nanoparticles are disposed at one end of the cross section;
A light source providing monochromatic incident light to the sensor unit;
An optical waveguide for transmitting light between the sensor unit and the light source;
An optical filter for receiving the output light emitted from the sensor unit to reflect a portion of the output light and to pass the remaining portion of the output light to separate the output light; And
And a measurement unit configured to converge the portion and the remaining portion of the separated output light, respectively. The method according to claim 1,
And the optical filter is a notch filter or an edge filter. The method according to claim 1,
And the optical filter reflects the central wavelength component λ ₁ of the output light corresponding to the central wavelength λ ₀ of the incident light and passes the scattered light component except for the central wavelength component λ ₁ of the output light. The method according to claim 1,
And the measuring unit includes a photo detector converging the portion of the output light reflected by the optical filter and a spectrometer converging the remaining portion of the output light passing through the optical filter. The method of claim 4, wherein
The optical detector applies the portion of the output light to LSPR quantitative analysis, and the spectrometer applies the remaining components of the output light to SERS qualitative analysis. The method of claim 5,
And the LSPR quantitative analysis and the SERS qualitative analysis are simultaneously performed from the monochromatic incident light. The method according to claim 1,
The metal nanoparticles are gold nanoparticles of about 50 nm, and a labeling material is formed on the gold nanoparticles. The method according to claim 1,
The sensor unit includes a plurality of optical fibers, wherein the plurality of optical fibers comprises a plurality of the metal nanoparticles are formed with a different labeling material. In the optical signal measuring method using the optical fiber based sensor system,
(a) preparing a sensor unit having at least one optical fiber in which metal nanoparticles are disposed in a cross section of one end;
(b) providing monochromatic incident light to the sensor unit;
(c) converging the output light from the sensor unit, reflecting a portion of the output light corresponding to the center wavelength of the incident light by an optical filter, and passing the remaining portion excluding the center wavelength of the incident light; And
(d) converging said portion of said output light corresponding to said center wavelength through a photo detector and converging said remaining portion, except for said center wavelength, through a spectrometer;
Optical signal measuring method using optical fiber based sensor system. 10. The method of claim 9,
In the step (d),
Converging the portion of the output light through the photo detector includes performing LSPR signal measurements on the portion of the output light, and converging the remaining portion of the output light through the spectrometer Optical signal measuring method using a fiber-based sensor system comprising the step of performing the SERS signal measurement for the remaining portion. The method of claim 9 or 10,
The portion of the output light is a center wavelength component λ ₁ of the output light corresponding to the center wavelength λ ₀ of the incident light, and the remaining portion of the output light is a scattered light component except the center wavelength component λ ₁ of the output light. Optical signal measuring method using the sensor system of the.

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