KR102181093B1 - Fluorescence amplifier device by long-range surface plasmon - Google Patents

Abstract

A fluorescence amplification device using long-range surface plasmons is provided. Fluorescence amplification device using long-distance surface plasmon according to an embodiment of the present invention comprises: a first metal layer provided to form one surface of an optical waveguide; A first dielectric formed by being stacked so as to contact the first metal layer and used as the optical waveguide; A second metal layer formed by being stacked so as to contact the other surface of the first dielectric material and provided to form the other surface of the optical waveguide; A second dielectric formed by stacking the second metal layer so that the other surface and one surface of the second metal layer are in contact with each other; And a fluorescent layer formed between the second metal layer and the second dielectric, bonded to the second metal layer, and emitting fluorescence after absorbing incident light. Using a surface plasmon amplification unit including: The fluorescence is amplified by generating surface plasmon.

Description

Fluorescence amplifier device by long-range surface plasmon}

The present invention relates to a fluorescence amplification device using a long-range surface plasmon, and more particularly, to a fluorescence amplification device that amplifies fluorescence generated from a fluorescent material using surface plasmon resonance.

Currently, fluorescence is in various fields such as medical diagnostic tests, biomaterial labels, light sources such as fluorescent tubes, imaging, research on inorganic/organic properties such as semiconductors, cosmic ray detection, mineralogy, environmental monitoring, etc. It is being applied in.

However, since the general fluorescence technique applied in these various fields mainly uses ultraviolet (UV) or blue light series in the visible light region with a short wavelength as an excitation light source, it is undesirable in slide glass, water, or other organic/inorganic materials. Autofluorescence may occur, and such autofluorescence has a problem of deteriorating the signal-to-noise ratio of fluorescence.

In addition, when a fluorescent dye is used at a high concentration or a strong excitation light source is used due to the photo-blenching effect caused by the interaction between the excited fluorescent molecules, the fluorescent molecules are photochemically unstable and photo-degradable. There is also a problem of degradation).

In addition, fluorescence signals emanating from fluorescent molecules in all directions are collected using an optical collector (a high-aberration objective or aspherical lens). In general, since the collection efficiency is low of about 1%, multi-channel analysis using blood When it is necessary to detect a small amount of target material such as a photoelectric amplification tube (PMT, PhotoMultiplier Tube), there is a problem of using an expensive photoelectric detector equipped with a detection signal amplification technology.

Korean Patent Publication No. 10-2009-0064917

In order to solve the problems of the prior art as described above, an embodiment of the present invention provides a fluorescence amplification device using a long-range surface plasmon effect capable of measuring fluorescence with high sensitivity by amplifying a fluorescence signal using a surface plasmon effect. I want to provide.

According to an aspect of the present invention for solving the above problems, there is provided a fluorescence amplification device using a long-range surface plasmon. The fluorescence amplification device using the long-distance surface plasmon includes: a first metal layer provided to form one surface of an optical waveguide; A first dielectric formed by being stacked so as to contact the first metal layer and used as the optical waveguide; A second metal layer formed by being stacked so as to contact the other surface of the first dielectric material and provided to form the other surface of the optical waveguide; A second dielectric formed by stacking the second metal layer so that the other surface and one surface of the second metal layer are in contact with each other; And a fluorescent layer formed between the second metal layer and the second dielectric, bonded to the second metal layer, and emitting fluorescence after absorbing incident light. Using a surface plasmon amplification unit including: The fluorescence is amplified by generating surface plasmon.

The first metal layer may be formed of silver or gold.

The first dielectric may be formed of a material having a refractive index similar to that of the second dielectric.

The first dielectric may be formed of a material having a refractive index of 1.30 to 1.38.

The first dielectric may be formed of Teflon.

The second metal layer may be formed to have a thickness of 15 nm or less in order to transmit the surface plasmon.

The second metal layer may be formed of gold.

The incident light may be transmitted through the other surface of the second dielectric, and the fluorescence may be emitted through the first metal layer.

The first metal layer is formed such that the inclined surface of the prism is in contact with the other surface of the prism, and the incident light is transmitted through one of the other two surfaces of the prism, and the fluorescence may be emitted through the other surface.

The incident light may be amplified by the surface plasmon phenomenon in the surface plasmon amplification unit to excite a fluorescent material included in the fluorescent layer.

The fluorescence amplification device using long-distance surface plasmons according to an embodiment of the present invention amplifies fluorescence generated from a fluorescent material so that a measurement sensor can measure a larger amount of fluorescence than before.

In addition, the fluorescence amplification device using long-distance surface plasmons according to an embodiment of the present invention is manufactured in a reflective type or a transmissive type, and thus can be selectively used according to the needs of users.

In addition, the fluorescence amplification device using a long-distance surface plasmon according to an embodiment of the present invention can further increase the amplification of fluorescence generated from the fluorescent material by simultaneously amplifying incident light incident on the fluorescent material in the case of a reflective device. It works.

In addition, the fluorescence amplification apparatus using long-distance surface plasmons according to an embodiment of the present invention has an effect of stabilizing fluorescent molecules by reducing photo bleaching.

In addition, the fluorescence amplification device using long-distance surface plasmon according to an embodiment of the present invention has an effect of reducing measurement noise by blocking self-luminous noise by a metal film.

1 is a diagram showing the configuration of a conventional fluorescent amplifying device using surface plasmon.
2 is a diagram showing (a) a transmission type and (b) a reflection type of a fluorescent amplifying apparatus using a long-range surface plasmon according to an embodiment of the present invention.
3 is a view showing the shape of waves dissipating and traveling in an optical waveguide of a fluorescent amplifying apparatus using long-distance surface plasmons according to an embodiment of the present invention.
4 is a surface plasmon amplification unit among devices used in an experiment to compare the efficiency of a fluorescent amplifying device using a long-range surface plasmon according to an embodiment of the present invention and another conventional fluorescent amplifying device, respectively (a) Only one metal layer exists. (B) a device in which the first metal layer is doped with a second metal layer, (c) a device in which a metal layer is doped on the dielectric, and (d) a surface plasmon amplification unit of the fluorescent amplification device according to an embodiment of the present invention. to be.
5 is a distance from a metal surface when incident light having a wavelength of (a) 498 nm and (b) 525 nm is used in the fluorescent amplifying device using a long-range surface plasmon and the fluorescent amplifying devices having different structures according to an embodiment of the present invention. It is a graph showing the electric field strength according to.
6 illustrates reflectance according to an incident angle when incident light having a wavelength of (a) 498 nm and (b) 525 nm is used in a fluorescence amplifying apparatus using a long-distance surface plasmon according to an exemplary embodiment of the present invention and a fluorescent amplifying apparatus having a different structure. This is the graph shown.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are assigned to the same or similar components throughout the specification.

1 is a diagram showing a simplified configuration of a conventional fluorescent amplifying device 100 using surface plasmon.

In the fluorescence amplification device 100 using surface plasmon, a Q-factor (Quality-factor), which is a quality factor of surface plasmon, is used as an important key factor. As the value of the Q-factor increases, the intensity of the evanescent field of the surface plasmon in the metal thin film in which the fluorescent molecules are present increases, thereby amplifying the fluorescent signal.

LRSPR, which is a structure capable of increasing the Q factor, is shown in FIG. 1, and since this structure is a technique published through many papers, it will be briefly described.

Referring to FIG. 1, a conventional fluorescent amplifying apparatus 100 using surface plasmon emits incident light A from a light source 110, and uses a medium having a high refractive index K value such as a prism. It converts to refracted light (B). The converted first refracted light (B) is moved in the form of surface plasmon light to be transmitted to the fluorescent material 123 formed at the top of the surface plasmon conversion unit 120 and is converted into amplified light (C) through the surface plasmon effect. do.

Thereafter, the fluorescence D generated by the fluorescent material 123 using the amplified light C passes through the inside of the surface plasmon conversion unit 120 again, is transmitted to the prism 130, and is refracted by the second refracted light ( It is changed to the form of E). Finally, the second refractive light E leaves the prism 130 and is converted into emission light F and enters the fluorescence measurement unit 150 so that the fluorescence amplification device 100 using the conventional surface plasmon is The incident light is amplified by using, and the fluorescent material 123 generates fluorescence D amplified by using the amplified light C, so that the fluorescence of higher output can be measured.

Here, the surface plasmon conversion unit 120 uses the surface plasmon effect to convert the first refractive light (B) into amplified light (C) in order of the dielectric 121, the metal layer 122, and the fluorescent material 123. Is formed to be stacked.

At this time, when light is incident in the direction of the dielectric 121, when certain conditions are satisfied, surface plasmon resonance occurs on the other side of the metal layer 122 that is not in contact with the dielectric 121, and by using this Structure in which the fluorescent material 123 doped on the other side emits fluorescence A method of using long-distance surface plasmon resonance is widely known in the art and is a process sufficiently understood by those skilled in the art, and thus, a description thereof will be omitted for convenience.

2 is a diagram showing the forms of (a) transmission type and (b) reflection type among the fluorescent amplification devices using long-range surface plasmons according to an embodiment of the present invention, and FIG. 3 is a diagram showing the long-range surface plasmons according to an embodiment of the present invention. A diagram showing the shape of waves dissipating and propagating in the optical waveguide of the used fluorescent amplifying device, and FIG. 4 is a comparison of the efficiency of a fluorescent amplifying device using a long-range surface plasmon according to an embodiment of the present invention and another conventional fluorescent amplifying device. Among the devices used in the experiment for the experiment, each of the surface plasmon amplification units (a) a device in which only one metal layer exists (b) a device in which the first metal layer is doped with a second metal layer, (c) a device in which a metal layer is doped on the top of the dielectric, and (D) a diagram showing a surface plasmon amplification unit of a fluorescent amplifying device according to an embodiment of the present invention, and FIG. 5 is a diagram showing a fluorescent amplifying device having a structure different from that of the fluorescent amplifying device using a long-range surface plasmon according to an embodiment of the present invention ( a) is a graph showing the electric field intensity according to the distance to the metal surface when incident light having a wavelength of 498 nm and (b) 525 nm is used, and FIG. 6 is a fluorescence amplifying apparatus using a long-range surface plasmon according to an embodiment of the present invention. In the case of using incident light having wavelengths of (a) 498 nm and (b) 525 nm in fluorescent amplifying devices of different structures, this is a graph showing the reflectance according to the incident angle.

Hereinafter, a fluorescence amplifying apparatus using a long-range surface plasmon according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 5.

Referring to FIG. 2, the fluorescence amplifying device 220 using long-range surface plasmon according to an embodiment of the present invention receives light from the light source unit 210 and emits fluorescence in the containing phosphor layer 224 and emits light. It is formed to emit one fluorescence toward the sensor 240.

The fluorescence amplification device 220 using long-distance surface plasmon may be formed in a reflective type 200a or a transmissive type 200b as shown in FIGS. 2A and 2B.

2A is a diagram showing a reflective fluorescent amplifying apparatus 200a using long-range surface plasmons. The reflective fluorescent amplifying apparatus 200a using long-range surface plasmons according to an embodiment of the present invention includes a light source unit 210, a surface plasmon conversion unit 220, a prism 230, a lens unit 240, and a sensor unit 250. ) Is formed to include.

Hereinafter, only the difference between the conventional fluorescent amplifying device 100 using surface plasmon of FIG. 1 and the fluorescent amplifying device 200a using long-range surface plasmon according to the present invention will be described.

Referring to FIG. 2A, in the fluorescence amplification apparatus 200a using long-distance surface plasmon according to an embodiment of the present invention, the surface plasmon change portion 220 includes a first metal layer 221, a first dielectric 222, and a second dielectric. It is formed of a metal layer 223, a fluorescent material 224, and a second dielectric 225.

The first metal layer 221 is formed at the bottom of the surface plasmon change unit 220. For example, when configuring the fluorescence amplification device 200a using a reflective long-distance surface plasmon, the prism 230 and one side are It can be formed to contact. Through this, the first metal layer 221 may receive the first refractive light B passing through the prism 230. In this case, the first metal layer 221 may be formed of silver (Ag) or gold (Au), for example.

The first dielectric 222 is formed by being stacked on the first metal layer 221. The first dielectric 222 may be formed to exhibit the same effect as one optical waveguide by using the first metal layer 221 and the second metal layer 223 to be described later. At this time, the first dielectric 222 may be formed to have a refractive index similar to that of the second dielectric 225 to be described later to generate surface plasmon as well as exhibit the same effect as the optical waveguide, and in particular, have a refractive index of 1.3 to 1.38. The branch may be formed of a material, and may be formed of one of these materials, Teflon.

The second metal layer 223 is formed by being stacked on the first dielectric 222. The second metal layer 223 may be formed to serve as a wall surface for forming the first dielectric 222 as an optical waveguide so that light can proceed inside the first dielectric 222. At this time, the second metal layer 223 may be formed to have a thickness of 15 nm or less for effective transmission of surface plasmons, and in particular, the material may be formed of gold (Au).

The fluorescent material 224 is formed to be adhered to one surface of the second metal layer 223. In this case, the fluorescent material 224 may be formed by being adhered to an upper surface of the second metal layer 223, not a surface where the first dielectric 222 and the second metal layer 223 contact each other.

The second dielectric 225 is formed to be stacked on the fluorescent material 224, that is, on the second metal layer 223. The second dielectric 225 may be stacked on the second metal layer 223 to form a layer of the fluorescent material 224 between the second metal layer 223 and the second dielectric 225. In this case, the second dielectric 225 may be formed of water having a refractive index of 1.33, for example.

In the reflective fluorescent amplifying apparatus 200a using long-distance surface plasmon according to an embodiment of the present invention shown in FIG. 2A, when incident light A is generated from the light source 210, the incident light ( A) is converted into first refracted light (B), and the converted first refracted light (B) is amplified using the surface plasmon conversion unit 220 to generate amplified light C, and the generated amplified light ( The fluorescent material 224 absorbing C) is formed to emit fluorescence (D). Thereafter, the fluorescence (D) emitted by the fluorescent material 224 passes through the surface plasmon conversion unit 220 and moves to the prism 230 and changes to the second refractive light E, and is emitted outside the prism 230. Light F may enter the sensor 250.

Here, referring to FIG. 3, the surface plasmon conversion unit 220 according to an embodiment of the present invention optically converts the first dielectric 222 having the first metal layer 221 and the second metal layer 223 as a boundary. Used as a waveguide.

The first dielectric 222 is formed so that the surface plasmon resonance (SPR) generated through the first metal layer 221 proceeds as shown in 1 to 3. In this case, the SPR that does not match the characteristics of the first dielectric 222 is dissipated after several reflections at the interface.

That is, referring to FIG. 3, in the surface plasmon conversion unit 220 according to an embodiment of the present invention, SPR 1 indicated by a solid line satisfies the characteristics of the first dielectric 222 and is not dissipated even when a plurality of reflections are performed. In addition, SPR2 and SPR3 disappear after several reflections because the characteristics such as reflection angle do not match with the first dielectric 222.

Through this phenomenon, the intensity of surface plasmon formed through the first metal layer 221 may be amplified through the first dielectric 222 formed as an optical waveguide. Thereafter, the amplified surface plasmon may generate surface plasmon again on both surfaces of the second metal layer 223 as amplified light C.

At this time, when the generated two surface plasmons have wavelengths of opposite phases to each other, they are recognized as a stabilized state, and a coupling effect and amplification effect due to quantum mechanics are generated, thereby providing a further amplified surface plasmon to the fluorescent material 224. The purity of the Q-factor of the surface plasmon increases, and thus the excitation value of the fluorescent material 224 may increase.

That is, in an embodiment of the present invention, by generating surface plasmons having an amplified intensity compared to conventional devices using an optical waveguide, the surface plasmons are formed at a longer distance than the conventional device, and thus the intensity reaching the fluorescent material 224 is also It can have an increasing configuration.

Meanwhile, the excited fluorescent material 224 emits fluorescence (D) and the fluorescence (D) generated in the process of returning to the original state is also quantum by using a surface plasmon amplification method using the first dielectric 222 as an optical waveguide. Since the coupling effect and the amplification effect due to the dynamics are generated and amplified, the fluorescent material 224 that has absorbed higher purity and energy emits fluorescence D of higher purity, and thus, in the sensor unit 250 In addition to increasing the fluorescence collection efficiency of, an additional detection signal amplification technique is not required, and noise that may be collected together in the collection process is more easily removed.

Meanwhile, FIG. 2B shows a transmission type fluorescence amplifying apparatus 200b using a long-distance surface plasmon according to an embodiment of the present invention. The transmission type fluorescence amplification device 200b is conceptually similar to the reflection type fluorescence amplification device 200a, and differences include the location of the light source 210 and the presence or absence of the prism 230.

That is, the fluorescence amplification devices 200a and 200b using long-distance surface plasmons of the present invention reflect the prism 230 by attaching the prism 230 to the lower portion of the surface plasmon amplification unit 220 according to the needs of the user or the condition of the light source 210 It may be configured and used as a type 200a, and generates fluorescence D using incident light A generated from the light source 210 provided on the second dielectric 225 except for the prism 230 In addition, the sensor unit 250 may be configured and used as a transmissive type 200b that receives the emitted light F.

In addition, as shown in FIGS. 2A and 2B, the user may change the configuration so that the sensor unit 250 receives the emitted light F more easily by adding the lens unit 240 as necessary.

On the other hand, Figures 4 to 6 show experimental results comparing the efficiency with the conventional fluorescent amplifying device using the reflective fluorescent amplifying device 200a among the fluorescent amplifying devices using long-distance surface plasmons of the present invention.

In this experiment, 498 nm and 525 nm were used as incident light, and alexa was used as a fluorescent material. In addition, silver (Ag) was used as the first metal layer, Teflon was used as the first dielectric, gold (Au) was used as the second metal layer, and water was used as the second dielectric material.

4 is a surface plasmon amplification unit among devices used in an experiment to compare the efficiency of a fluorescent amplifying device using a long-range surface plasmon according to an embodiment of the present invention and another conventional fluorescent amplifying device, respectively (a) Only one metal layer exists. (B) a device in which the first metal layer is doped with a second metal layer, (c) a device in which a metal layer is doped on the dielectric, and (d) a surface plasmon amplification unit of the fluorescent amplification device according to an embodiment of the present invention. to be.

Referring to Figure 4, the configuration used in this experiment is a basic reflective fluorescent amplifying device, for comparison, (a) a device in which only one metal layer exists, and (b) a device in which a second metal layer is doped on top of the first metal layer. , (c) a device doped with a metal layer on an upper portion of the dielectric, and (d) a view showing only the surface plasmon amplification units having different configurations in the reflective fluorescent amplifying device according to an embodiment of the present invention.

Hereinafter, in the experiments of Figs. 5 and 6, the results of experiments performed by four devices including an embodiment of the present invention are shown and described using graphs, so that the fluorescence amplifying devices 200a and 200b formed by the present invention Let us confirm that it provides better results than conventional devices.

Looking at the experimental result data of FIGS. 5A and 5B, first, the legend indicates the structures of FIGS. 4A, 4B, 4C and 4D in order from the top.

5A shows the magnitude of the electric field intensity according to the distance from the metal surface when the wavelength of the incident light is 498 nm, and FIG. 5B shows the magnitude of the electric field strength according to the distance from the metal surface when the incident light wavelength is 525 nm. Looking at the graph, it was observed that the electric field intensity was large at the same distance as the metal surface in the order of FIGS. 4D, 4C, 4B and 4A regardless of the length of the wavelength. In other words, when the electric field strength is measured at the same distance from the metal surface, the electric field strength can be measured the largest when the reflective fluorescent amplifying device according to the present invention is used than the conventional three devices, which is the other three conventional devices. It is interpreted that the amplification efficiency of the fluorescent amplifying device according to the present invention is higher.

Meanwhile, FIG. 6A is a diagram showing reflectance according to an incident angle when the wavelength of incident light is 498 nm, and FIG. 6B is a diagram illustrating reflectance according to an incident angle when the incident light wavelength is 525 nm.

6A and 6B, when the device of FIG. 4A is used, the width of the inverse peak (valley) of the wavelength is the widest, and when the fluorescent amplification device of the present invention shown in FIG. 4D is used, the width of the reverse peak (valley) You can see that is the narrowest.

At this time, as the change in reflectance according to the incident angle appears sharply, that is, the narrower the range of the incident angle in which the reflectance decreases sharply, the higher the efficiency than the remaining three conventional devices because the Q-factor of the above-described surface plasmon increases. It can be seen that fluorescence amplification can be performed.

Although an embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in the present specification, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same idea. It will be possible to easily propose other embodiments by changing, deleting, adding, etc., but it will be said that this is also within the scope of the present invention.

100: Fluorescence amplification device using conventional surface plasmon
110, 210: light source 120, 220: surface plasmon amplification unit
121: dielectric 122: metal layer
123,224: fluorescent material 130, 230: prism
140, 240: lens unit 150, 250: sensor unit
200a: Reflective fluorescence amplification device using long-distance surface plasmon
200b: Transmission type fluorescence amplification device using long-range surface plasmon
221: first metal layer 222: first dielectric
223: second metal layer 225: second dielectric

Claims (10)

A first metal layer provided to form one surface of the optical waveguide;
A first dielectric formed by being stacked so as to contact the first metal layer and used as the optical waveguide;
A second metal layer formed by being stacked so as to contact the other surface of the first dielectric material and provided to form the other surface of the optical waveguide;
A second dielectric formed by stacking the second metal layer so that the other surface and one surface of the second metal layer are in contact with each other; And
A surface plasmon amplification unit including; a fluorescent layer formed between the second metal layer and the second dielectric, bonded to the second metal layer, and emitting fluorescence after absorbing incident light. Generating a plasmon phenomenon to amplify the fluorescence,
The first dielectric is used as an optical waveguide between the first metal layer and the second metal layer, and a long-range surface plasmon that amplifies the intensity of surface plasmon formed through the first metal layer and the surface plasmon formed through the second metal layer. Fluorescence amplification device using. The method of claim 1,
The first metal layer is a fluorescent amplifying device using a long-range surface plasmon formed of silver or gold. The method of claim 2,
The first dielectric is a fluorescent amplification device using a long-range surface plasmon formed of a material having a refractive index similar to that of the second dielectric. The method of claim 3,
The first dielectric is a fluorescent amplifying device using a long-range surface plasmon formed of a material having a refractive index of 1.30 to 1.38. The method of claim 4,
The first dielectric is a fluorescent amplification device using long-range surface plasmon formed of Teflon. The method of claim 3,
The second metal layer is a fluorescent amplification device using a long-distance surface plasmon formed to a thickness of 15 nm or less to transmit the surface plasmon. The method of claim 6,
The second metal layer is a fluorescent amplifying device using long-distance surface plasmon formed of gold. The method of claim 3,
Fluorescence amplification device using long-distance surface plasmon for receiving the incident light through the other surface of the second dielectric and emitting the fluorescence through the first metal layer. The method of claim 3,
Fluorescence using long-distance surface plasmon that is formed so that the inclined surface of the prism is in contact with the other surface of the first metal layer, receives the incident light through one of the other two surfaces of the prism, and emits the fluorescence through the other surface Amplification device. The method of claim 9,
The incident light is amplified by the surface plasmon phenomenon in the surface plasmon amplification unit to excite a fluorescent material included in the fluorescent layer.

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