KR101178203B1 - A microfluidic device for analyzing biochemical sample optically - Google Patents

Abstract

A microfluidic device for optically analyzing a biochemical sample is disclosed. The microfluidic device includes a U-shaped microchannel, an inlet for introducing a sample into the microchannel, and an outlet through which the sample of the microchannel is discharged, and includes a left channel and a right side of the U-shaped microchannel. The partition wall exists between the flow paths, and the flow path is U-shaped so that fluid flows along the outer surface of the partition wall. The refractive index of the partition wall is higher than that of water, and serves as a waveguide of light. Thus, it is possible to optically analyze biological samples.

Microfluidic Devices, Microchannels, Optics, Fiber Optics, Fluorescence, Refractive Index

Description

Microfluidic device for analyzing biochemical sample optically

The present invention relates to a microfluidic device for optically analyzing a biochemical sample.

Currently, the bio industry is conducting a lot of research and commercialization of point of care (POC) and lab-on-a-chip (LOC). The lab-on-a-chip (LOC) is a test apparatus for performing experiments in various fields such as biology, medicine, and pharmacology in one plastic microfluidic device.

Biomaterials such as proteins such as antigens or antibodies, DNA, viruses, bacteria, animal cells, plant cells, tissues, and the like within the microchannels of the microfluidic device (herein, such biomaterials are collectively referred to as "biochemical samples" or A sample containing "biochemical material") is injected or caused to flow through the channel to cause a biochemical reaction, and the reaction result is analyzed by an analytical device.

Currently, methods for optically detecting and analyzing biochemicals are known. For example, an antibody may be attached to the surface of an optical fiber, react with a sample containing an antigen to cause an antigen-antibody reaction, and then react with a secondary antibody labeled with a fluorescent material to optically emit light from the fluorescent material. Analyze with At this time, since light emitted from the fluorescent material enters the optical fiber and flows through the optical fiber, the optical signal can be analyzed using a detection device provided at the end of the optical fiber.

The present invention is to provide a microfluidic device for optically analyzing a biochemical sample.

The present invention also provides a method for analyzing biochemicals in a sample using the microfluidic device.

In addition, the present invention is to provide a method for manufacturing the microfluidic device.

The present invention relates to a microfluidic device for optically analyzing a biochemical sample, and includes a U-shaped microchannel, an inlet through which a sample enters into the microchannel, and an outlet through which a sample of the microchannel flows out. Here, the partition wall is present between the left channel and the right channel of the U-shaped microchannel, the flow path is U-shaped so that the fluid flows along the outer surface of the partition wall.

The refractive index of the partition wall is higher than that of water, and serves as a waveguide of light. Accordingly, the light entering the partition wall travels in the longitudinal direction along the partition wall.

A hole for inserting the optical fiber is formed at the rear end of the surface from which the partition wall protrudes. The hole is formed in the longitudinal direction on an extension line in the longitudinal direction of the partition wall.

In addition, the present invention relates to a method for analyzing a biochemical in a sample using the microfluidic device, by introducing a first binding material that specifically reacts with the biochemical to the microchannel of the microfluidic device, Attaching into the microchannels; Introducing a sample containing the biochemical into the microchannel to react the first binding substance with the biochemical in the sample; Reacting specifically with the biochemical material, introducing a second binding material to which the fluorescent material is attached into the microchannel, and reacting the biochemical material combined with the first binding material with the second binding material; Irradiating light into the partition wall to excite the fluorescent material; And analyzing the light emitted by the fluorescent material transmitted by the partition wall.

In addition, the present invention relates to a method for manufacturing the microfluidic device, comprising: depositing a photoresist on a metal substrate; Patterning the photoresist layer; Plating a portion of the photoresist layer patterned and removed with the metal on the metal substrate; Removing all of the photoresist layer; Molding the plastic with the remaining metal substrate as a mold, and then removing the mold to manufacture a substrate on which microchannels and partitions are formed; Forming inlets and outlets at both ends of the microchannels of the substrate; And bonding the substrate with other flat plastics.

In the present invention, a plastic structure serving as a chamber and an optical fiber as a space into which a sample is injected is implemented in a microfluidic device. In the present invention, the time for fixing the biochemical material to the plastic is short, and the reaction time is also short. In addition, the microfluidic device according to the present invention is small in size, easy to carry, simple to manufacture, low in manufacturing cost, and can be easily used for one-time use.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited by the following examples.

1A is a perspective view of a microfluidic device according to an embodiment of the present invention. FIG. 1B is a plan view of the microfluidic device shown in FIG. 1A, and FIG. 1C is a cross-sectional view taken along line A′-A of the microfluidic device shown in FIG. 1A, and FIG. 1D is a micrograph shown in FIG. 1A. It is sectional drawing which cut | disconnected the BB 'line of a fluid apparatus.

The microfluidic device 1 is for optically analyzing a biochemical sample, the U-shaped microchannel 20, the inlet 10 for introducing the sample into the microchannel 20, and the microchannel 20 And an outlet 30 through which the sample of the outlet flows out.

A partition wall 40 exists between the left flow passage 21 and the right flow passage 22 of the U-shaped microchannel 20. The microchannel 20 has a U-shaped flow path such that fluid flows along the outer surface of the partition wall 40, that is, flows through the right side surface of the partition wall 40 to the left surface of the partition wall 40. There is no particular limitation on the width of the microchannel (b in FIG. 1B), but it is manufactured in the range of 100 to 500 μm.

The partition 40 serves as a waveguide of light. Therefore, light entering the barrier rib 40 travels in the longitudinal direction along the barrier rib 40.

For this purpose, the material of the partition 40 is preferably transparent. The partition 40 is conveniently manufactured to be integrated with the microfluidic device 1. Therefore, the microfluidic device 1 preferably uses glass or plastic of a transparent material.

In general, a biochemical sample is a dispersion system in which the dispersion medium is water. Therefore, when the refractive index of the partition 40 is higher than water, if the microchannel 20 is filled with a biochemical sample, the light incident into the partition 40 at an angle greater than or equal to a critical angle may enter into the biochemical sample. Total reflection at the boundary of Therefore, the light entering the partition 40 proceeds in the longitudinal direction along the inside of the partition 40.

The material of the barrier rib 40 is larger than the refractive index of water (1.33). Preferably, a polymeric material having a refractive index in the range of 1.4 to 1.6 is used. For example, the partition 40 may be formed of a polymer material such as a cyclic olefin copolymer (COC), polycarbonate (PC, polycarbonate), or polymethylmethacrylate (PMMA). It is preferable to use it as the apparatus (1).

The width of the partition wall 40 (a in FIG. 1B) may be formed in a range of 100 to 1000 μm (preferably 200 to 600 μm), but is not limited thereto. As shown in FIG. 1B, it is advantageous to fabricate the partition 40 in a needle shape in which the width becomes narrower toward the end, thereby optically detecting the sample. The partition 40 may be manufactured to have a constant width a, as in the other exemplary embodiment shown in FIG. 2.

The height of the partition wall 40 (h in FIG. 1C) becomes the height of the microchannel 20 as shown in FIG. 1C. The height (h of FIG. 1C) of the partition wall 40 is preferably formed to be 100 to 300 μm, but is not limited thereto.

On the other hand, a hole 50 is formed at the rear end of the surface from which the partition wall 40 protrudes so that the optical fiber can be inserted. The hole 50 is formed in the longitudinal direction on an extension line in the longitudinal direction of the partition wall 40. After the optical fiber is inserted into the hole 50, light is applied into the partition wall through the optical fiber. In addition, light emitted through the partition wall may be detected from the outside through the optical fiber using an optical signal detecting device (not shown).

The microfluidic device 1 may be manufactured by bonding the upper substrate 2 and the lower substrate 3 to each other. In this case, as shown in FIG. 1C or 1D, the microchannel 20, the inlet 10, the outlet 30, and the partition 40 are formed on the upper substrate 2 or the lower substrate 3. After forming in advance, the upper substrate 2 and the lower substrate 3 may be bonded to each other to produce.

3 is a perspective view of a cross-sectional view of the microfluidic device according to the embodiment of the present invention. As shown in part X of FIG. 3, the end of the hole 50 is preferably convex in order to collect light emitted through the partition wall 40. The convex portion 52 serves as a cylindrical lens to collect light.

The convexly formed end portion X of the hole 50 is in contact with the optical fiber so that light of the optical fiber enters the partition wall, and light from the partition wall enters the optical fiber.

4 is a view showing a state in which the optical fiber is coupled to the microfluidic device according to an embodiment of the present invention. In general, the optical fiber 90 is composed of a central core 94 and a cladding 92 surrounding the outer circumferential surface of the core 94. The end of the optical fiber 90 is inserted into the hole 50 of the microfluidic device, so as to contact the convexly formed portion 52 of the end X of the hole 50 to optically pass the light.

5A to 5C are diagrams for explaining a process of analyzing a biochemical material (eg, an antigen) in a sample using a microfluidic device according to an embodiment of the present invention.

First, a first binding material (eg, specifically binding to the antigen) that specifically reacts with the biochemical (antigen) into the microchannel 20 through the inlet 10 of the microfluidic device 1. After the solution containing the antibody (72) is introduced, it is left to cure for about 5 minutes. At this time, the material of the partition 40 is a polymer such as cyclic olefin copolymer (COC), polycarbonate (PC), or polymethyl methacrylate (PMMA), and these polymers are hydrophobic and are shown in FIG. 5A. As can be seen, a protein such as antibody 72 can be attached directly to the surface of partition 40 to fix it.

Thereafter, the solution in the microchannel 20 is discharged through the outlet 30 and then washed with the buffer solution. In the present invention, the antibody can be easily fixed, and the experiment time can be greatly shortened.

Subsequently, the sample containing the antigen 74 is introduced into the microchannel 20 through the inlet 10 of the microfluidic device 1, and incubated for about 5 minutes to attach the antibody attached to the partition 40. 72) and antigen 74 cause an antigen-antibody reaction (FIG. 5B). Thereafter, the solution in the microchannel 20 is discharged through the outlet 30 and then washed with the buffer solution.

Thereafter, the specific reaction with the antigen 74, the second binding material (second antibody) 76 attached to the fluorescent material 78 is introduced into the microchannel 20, the first antibody ( 72) and the second antibody 78 is reacted with the antigen 76 associated with (72).

Subsequently, an optical fiber (90 in FIG. 4) having a diameter of about 400 μm is inserted into the hole 50, and the fluorescent material 78 attached to the second antibody 76 as shown in FIG. 5D. The laser light of a specific wavelength band (for example, 635 nm) capable of exciting the light is irradiated into the partition 40 through the optical fiber (90 in FIG. 4). Here, since there is a difference in refractive index at the interface between the partition 40 and the solution filling the microchannel 20, the light is 100% totally reflected like the optical fiber, so that there is no loss of light at all. Therefore, some of the light entering the partition 40 is transmitted to the outside of the partition 40 to excite the fluorescent material 78 on the side wall of the partition 40.

The excited fluorescent material 78 emits light of a specific wavelength band (for example, 670 nm). A portion of the light emitted by the fluorescent material 78 thus excited enters the partition 40 and flows along the partition, and the light is transmitted to the external optical signal detection device (not shown) by the optical fiber (90 in FIG. 4). Is delivered. The optical signal detection device may analyze the optical signal of the fluorescent material, thereby qualitatively or quantitatively analyzing the antigen in the sample.

6A to 6H are cross-sectional views illustrating a method of manufacturing a microfluidic device according to an embodiment of the present invention. This process cross-sectional view is shown with reference to the cross section taken along the line A'-A in FIG. 1A.

First, as shown in 6a, SU-8 (200), which is a photoresist, is spin-coated on a metal substrate 100 such as nickel (Ni) and laminated at a height of about 200 mu m. The height of the photoresist is the height of the microchannel (20 in FIG. 1).

Thereafter, as shown in FIG. 6B, the photoresist layer 200 is patterned.

Subsequently, as shown in FIG. 6C, the portion 110 in which the photoresist layer is patterned and removed on the metal substrate 100 is plated with the same Ni metal as the substrate 100.

After removing all of the photoresist layer, the remaining metal substrate 100 becomes a mold as shown in FIG. 6D.

Thereafter, as shown in FIG. 6E, the plastic 2 is molded using the metal substrate 100 as a mold.

Thereafter, by removing the mold 100, the upper substrate 2 on which the microchannels 20, the partition walls, and the like are formed is manufactured as shown in FIG. 6F.

Thereafter, as shown in FIG. 6G, holes are formed at both ends of the microchannel in the upper substrate 2 to become the inlet 10 and the outlet 30.

Thereafter, as shown in FIG. 6H, the upper substrate 2 may be bonded to the lower substrate 3 of another flat plastic material to manufacture a microfluidic device.

The microfluidic device manufactured as described above can be used for single use because the manufacturing process is simple and the manufacturing cost is low.

The embodiment according to the present invention is not limited to the above-described embodiments, and various alternatives, modifications, and changes can be made without departing from the scope of the present invention.

Figure 1a is a perspective view of a microfluidic device according to an embodiment of the present invention.

1B is a plan view of the microfluidic device shown in FIG. 1A.

1C is a cross-sectional view taken along line A′-A of the microfluidic device shown in FIG. 1A.

1D is a cross-sectional view taken along line B-B ′ of the microfluidic device shown in FIG. 1A.

2 is a plan view of a microfluidic device according to another embodiment of the present invention.

Figure 3 is a perspective view of the cross-section cut in the transverse direction microfluidic device according to an embodiment of the present invention.

Figure 4 is a view for explaining how the optical fiber is coupled to the microfluidic device according to an embodiment of the present invention.

Figures 5a to 5c is a view for explaining the process of analyzing the biochemical material in the sample using a microfluidic device according to an embodiment of the present invention.

6A to 6H are cross-sectional views illustrating a method of manufacturing a microfluidic device according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1 microfluidic device 2 upper substrate

3: lower substrate 10: inlet

20: fine channel 30: outlet

40: partition 50: hole for the optical fiber is inserted

78 fluorescent material 90 optical fiber

Claims (13)

A microfluidic device for optically analyzing a biochemical sample, U-shaped microchannel, An inlet for introducing a sample into the microchannel, and Including an outlet for outflow of the sample of the microchannel, The partition wall is present between the left channel and the right channel of the U-shaped microchannel, characterized in that the flow path is U-shaped so that the fluid flows along the outer surface of the partition, the refractive index of the partition is higher than water , Acting as an optical waveguide, the light entering the interior of the partition wall is a microfluidic device characterized in that the light in the longitudinal direction along the partition wall. delete delete delete delete A microfluidic device for optically analyzing a biochemical sample, U-shaped microchannel, An inlet for introducing a sample into the microchannel, and Including an outlet for outflow of the sample of the microchannel, The partition wall is present between the left channel and the right channel of the U-shaped microchannel, characterized in that the flow path is U-shaped so that the fluid flows along the outer surface of the partition wall, the partition of the surface protruding The rear end is formed with a hole for inserting the optical fiber, the hole is microfluidic device, characterized in that formed in the longitudinal direction on the extension line in the longitudinal direction of the partition wall. 7. The microfluidic device of claim 6, wherein an end of the hole is formed convex to collect light emitted through the partition wall, and an end portion of the hole formed convex is connected to the optical fiber. The microfluidic device of claim 1, wherein the partition wall has a shape that becomes narrower toward the end. delete delete A method for analyzing biochemicals in a sample using the microfluidic device according to any one of claims 1, 6, 7, and 8, Introducing a first binding material that specifically reacts with the biochemical to the microchannel of the microfluidic device, and attaching the first binding material to the microchannel; Introducing a sample containing the biochemical into the microchannel to react the first binding substance with the biochemical in the sample; As a second binding material that specifically reacts with the biochemical material, a second binding material having a fluorescent material attached thereto is introduced into the microchannel, thereby reacting the biochemical material bound to the first binding material with the second binding material. step; Irradiating light into the partition wall to excite the fluorescent material; And And analyzing the light emitted from the fluorescent material, which is transmitted by the partition wall. The method of claim 11, wherein the biochemical is an antigen, and the first binding agent and the second binding agent are antibodies that specifically react with the antigen. A method of manufacturing a microfluidic device according to any one of claims 1, 6, 7, and 8, Depositing a photoresist on the metal substrate; Patterning the photoresist layer; Plating a portion of the photoresist layer patterned and removed with the metal on the metal substrate; Removing all of the photoresist layer; Molding the plastic with the remaining metal substrate as a mold, and then removing the mold to manufacture a substrate on which microchannels and partitions are formed; Forming inlets and outlets at both ends of the microchannels of the substrate; And And bonding the substrate to another flat plate-like plastic.

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