SPR-based microfluidic system and method of using the same

Abstract

The present invention provides a microfluidic system based on SPR and a method for using the same, belonging to the field of microfluidic technology. The present invention includes a dual-channel sampling microfluidic system formed by a first single-channel sampling microfluidic system and a second single-channel sampling microfluidic system having the same structure connected in series; and a plasma resonance sensing detection device for extracting the resonance angle change caused by the interaction of biomolecules on the convergence line of the sensing membrane in the reaction pool to realize the dynamic detection of molecular interactions. The present invention consumes a small amount of sample, is not easy to generate bubbles, and can improve the sensitivity and stability of detection.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and in particular to a microfluidic system based on SPR and a use method thereof. Background Art

[0002] Surface plasmon resonance (SPR) sensing technology has become an important tool for exploring molecular interactions with its advantages of label-free, high time resolution, non-invasiveness, and high sensitivity, and has been widely used in many fields such as biochemical analysis, drug development, disease diagnosis, and environmental monitoring. The SPR phenomenon was first discovered by physicist Wood in 1902, and Turbader, Farrell, and others have conducted theoretical analysis of the phenomenon. So far, the theoretical research on SPR has been basically mature. Its principle is simply described as follows: when a beam of TM polarized light is incident on the metal-medium surface at an angle greater than the critical angle, total reflection will occur, and an evanescent wave will be generated on the metal surface. The free electrons on the metal surface are excited by the evanescent wave to form a surface plasma wave. When the optical parameters such as the angle and wavelength of the incident light meet the wave vector matching conditions, the evanescent wave wave vector matches the surface plasma wave vector and resonance occurs. There are currently four main SPR sensing technologies, including: intensity-type SPR sensing technology, angle-type SPR sensing technology, phase-type SPR sensing technology, and wavelength-type SPR sensing technology. Intensity-type SPR sensing technology is to fix the incident wavelength and incident angle, monitor the linear intensity of the angular spectrum or spectral curve when the SPR phenomenon occurs, and reflect the change of the sample's refractive index through the change of intensity; angle-type SPR sensing technology is to fix the incident wavelength, monitor the change of the SPR resonance angle by continuously scanning the incident angle, and thus reflect the change of the sample's refractive index; phase-type SPR sensing technology is to monitor the phase of the incident and reflected light, and obtain the refractive index change information of the sample through the phase difference. Wavelength-type SPR sensing technology reflects the change of the sample's refractive index through the change of the resonant wavelength. It is mainly divided into two detection methods: one is to use a spectrometer and other instruments to perform spectral analysis on broadband reflected light to obtain the spectral curve when the SPR phenomenon occurs; the other is to use a monochromator to perform wavelength scanning on broadband incident light, and the detector synchronously records the reflection intensity of different wavelengths, and reconstructs the SPR spectral curve through software. The incident angle is fixed in both monitoring methods. The SPR sensor injection system usually uses a flow cell for injection, which has a simple structure. However, the flow cell is large in size, consumes a large amount of sample, and is prone to bubbles when changing samples, affecting the sensitivity and stability of the detection. Summary of the invention

[0003] In view of this, in order to solve the technical problems in the prior art that the circulation pool is large in volume, consumes a large amount of sample, easily generates bubbles when changing samples, and affects the sensitivity and stability of detection, on the one hand, the present invention provides a microfluidic system based on SPR, which consumes a small amount of sample, is not easy to generate bubbles, and can improve the sensitivity and stability of detection.

[0004] To achieve the above object, the present invention provides the following technical solutions: A microfluidic system based on SPR, comprising: The sampling microfluidic system is a dual-channel sampling microfluidic system formed by connecting a first single-channel sampling microfluidic system and a second single-channel sampling microfluidic system with the same structure in series; Plasma resonance sensing detection device, used to extract the change of resonance angle caused by the interaction of biomolecules on the convergence line of the sensing membrane in the reaction pool, and realize the dynamic detection of molecular interaction; The first single-channel sample injection microfluidic system comprises: a liquid reservoir having an injection port, a buffer port, and a waste port; A reaction tank, connected to the liquid storage tank, comprising a first reaction tank and a second reaction tank connected in parallel to each other and connected to the liquid storage tank; After the first valve is arranged on the injection flow path of the injection port, it is divided into three flow paths respectively connected with the liquid storage tank, the reaction tank and the waste liquid port, the second valve is arranged on the flow path connected with the liquid storage tank, the third valve and the tenth valve are arranged on the left and right ends of the connection point where the injection flow path is connected with the reaction tank flow path, respectively, and the eleventh valve and the ninth valve are arranged on the upper and lower ends of the connection point and located on the injection flow path respectively; A fourth valve and a sixth valve are respectively provided on the flow path connecting the first reaction pool and the second reaction pool with the liquid storage pool, a fifth valve and an eighth valve are respectively provided at both ends of the first reaction pool and the second reaction pool in parallel, and a seventh valve is provided on the flow path connecting the reaction pool with the waste liquid port.

[0005] Preferably, the plasma resonance sensing detection device comprises a light source, a first aspheric lens, a polarizer, a first cylindrical lens, a second cylindrical lens, a sensing film, a second aspheric lens, a third cylindrical lens and a charge coupled device; The monochromatic incoherent light emitted by the light source is collimated and expanded into parallel light by the first aspheric lens, then forms P polarized light through the polarizer, and then converges to the second cylindrical lens through the first cylindrical lens, and then converges to the surface of the sensing film to form a convergence line. The molecular interaction information on the surface of the sensing film is sensed by the change of the resonance angle, and then reflected from the second cylindrical lens, converted into parallel light by the second aspheric lens, and then converged into a line by the third cylindrical lens. The charge coupled device records the angular spectrum curve of the converged light, and the computer performs data analysis to extract the resonance angle change caused by the interaction of biomolecules on the convergence line at the sensing film, thereby realizing the dynamic detection of molecular interactions.

[0006] The present invention also provides a method for using the above-mentioned SPR-based microfluidic system, comprising the following steps: Step (1), all flow paths are filled with buffer, the second valve, the ninth valve, the eleventh valve of the first single-channel sampling microfluidic system and the twelfth valve, the twentieth valve and the twenty-second valve of the second single-channel sampling microfluidic system are opened, and the other valves are closed, and buffer is injected from the first buffer port of the first single-channel sampling microfluidic system and the second buffer port of the second single-channel sampling microfluidic system in parallel, and the first liquid reservoir of the first single-channel sampling microfluidic system and the second liquid reservoir of the second single-channel sampling microfluidic system are filled with buffer; Step (2), all valves are closed, the first valve, the second valve, the twelfth valve and the thirteenth valve of the first single-channel sample injection microfluidic system and the second single-channel sample injection microfluidic system are opened, and the buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path; Preferably, the method further comprises the following steps: Step (3), all valves are closed, the ninth valve, the tenth valve, and the twentieth valve and the twenty-first valve of the first single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the first buffer port to the ninth valve, then to the tenth valve, and finally to the waste port.

[0007] Preferably, the method further comprises the following steps: Step (4), all valves are closed, the first valve, the tenth valve, the eleventh valve and the twelfth valve, the twenty-first valve and the twenty-second valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the eleventh valve to the first and finally to the waste port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve to the twenty-second valve and then to the twelfth valve and finally to the waste port.

[0008] Preferably, the method further comprises the following steps: Step (5), all valves are closed, the tenth valve, the third valve, the fourth valve, the fifth valve and the twenty-first valve, the fourteenth valve, the fifteenth valve and the sixteenth valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the third valve, the fourth valve, the fifth valve and finally to the waste port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve, the fourteenth valve, the fifteenth valve and the sixteenth valve and finally to the waste port.

[0009] Preferably, the method further comprises the following steps: Step (6), all valves are closed, the tenth valve, the third valve, the eighth valve, the sixth valve, the fifth valve and the twenty-first valve, the fourteenth valve, the nineteenth valve, the seventeenth valve and the sixteenth valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the third valve, the eighth valve, the sixth valve, the fifth valve and finally to the waste liquid port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve, the fourteenth valve, the nineteenth valve, the seventeenth valve, the sixteenth valve and finally to the waste liquid port.

[0010] Preferably, the method further comprises the following steps: Step (7), all valves are closed, the tenth valve, the third valve, the eighth valve, the seventh valve and the twenty-first valve, the fourteenth valve, the nineteenth valve and the eighteenth valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the third valve, the eighth valve, the seventh valve and finally to the waste port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve, the fourteenth valve, the nineteenth valve, the eighteenth valve and finally to the waste port.

[0011] Preferably, the method further comprises the following steps: Step (8): injecting the liquid to be tested Close all valves, open the first valve, the second valve, the tenth valve, the ninth valve, and the twelfth valve, the thirteenth valve, the twenty-first valve, and the twentieth valve of the second single-channel injection microfluidic system, and inject the sample into the first liquid reservoir of the first single-channel injection microfluidic system and the second liquid reservoir of the second single-channel injection microfluidic system from the first injection port of the first single-channel injection microfluidic system and the second injection port of the second single-channel injection microfluidic system, respectively; Close all valves, open the second valve, the eleventh valve, the third valve, the eighth valve, the fourth valve, the sixth valve, the fifth valve and the thirteenth valve, the twenty-second valve, the fourteenth valve, the nineteenth valve, the fifteenth valve, the sixteenth valve and the seventeenth valve of the second single-channel injection microfluidic system, inject buffer through the first buffer port and the second buffer port, inject the samples in the first liquid storage tank and the second liquid storage tank into the first reaction tank and the second reaction tank of the first single-channel injection microfluidic system and the third reaction tank and the fourth reaction tank of the second single-channel injection microfluidic system, to achieve four-way parallel detection.

[0012] Preferably, if all valves are closed during the sample injection process, and then the second valve, the eleventh valve, the third valve, the fourth valve, the sixth valve, the seventh valve and the thirteenth valve, the twenty-second valve, the fourteenth valve, the fifteenth valve, the seventeenth valve and the eighteenth valve of the second single-channel injection microfluidic system are opened at the same time, the function of connecting the first reaction pool in series with the second reaction pool and the third reaction pool in series with the fourth reaction pool can be achieved.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a microfluidic system based on SPR, in which liquid path control is all performed in the microfluidic system, the microfluidic system has a small volume, a fast flow path (flow path) switching speed, less mixing and contamination between samples, less sample consumption, less bubbles are generated, and the sensitivity and stability of detection can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the SPR detection device; Figure 2 It is a structural schematic diagram of the present invention; Figure 3 It is a schematic diagram of the structure of a dual-channel injection microfluidic system; In the figure, 1, light source; 2, first aspheric lens; 3, polarizer; 4, first cylindrical lens; 5, second cylindrical lens; 6, sensing film; 7, second aspheric lens; 8, third cylindrical lens; 9, charge coupled device; 10, reaction film; 100, first liquid reservoir; 101, first injection port; 102, first buffer port; 103, first reaction pool; 104, second reaction pool; 105, first valve; 106, second valve; 107, third valve; 108, fourth valve; 109, fifth valve; 110, sixth valve; 111, seventh valve; 112, eighth valve; 113, eighth valve; 114, eighth valve; 115, eighth valve; 116, eighth valve; 117, eighth valve; 118, eighth valve; 119, eighth valve; 120, eighth valve; 121, eighth valve; 122, eighth valve; 123, eighth valve; 124, eighth valve; 125, eighth valve; 126, eighth valve; 127, eighth valve; 128, eighth valve; 129, eighth valve; 130, eighth valve; 131, eighth valve; 132, eighth valve; 133, eighth valve; 134, eighth valve; 135, eighth valve; 136, eighth valve; 137, eighth valve; 138, eighth valve; 139, eighth valve; 140, eighth valve; 141, eighth valve; 142, eighth valve; 143, eighth valve; 144, eighth valve; 145, eighth valve; 146, eighth valve; 147, eighth valve; 148, eighth valve; 149, eighth valve; 149, eighth valve; 140, eighth valve; 141, eighth valve; 149, eighth valve 3. The ninth valve; 114. The tenth valve; 115. The eleventh valve; 200. The second liquid storage tank; 201. The second injection port; 202. The second buffer port; 203. The third reaction tank; 204. The fourth reaction tank; 205. The twelfth valve; 206. The thirteenth valve; 207. The fourteenth valve; 208. The fifteenth valve; 209. The sixteenth valve; 210. The seventeenth valve; 211. The eighteenth valve; 212. The nineteenth valve; 213. The twentieth valve; 214. The twenty-first valve; 215. The twenty-second valve; 300. The injection path; 301. The waste liquid port. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] like Figure 1-3 As shown, the present invention provides a microfluidic system based on SPR, comprising: The sampling microfluidic system is a dual-channel sampling microfluidic system formed by connecting a first single-channel sampling microfluidic system and a second single-channel sampling microfluidic system with the same structure in series; Plasma resonance sensing detection device, used to extract the change of resonance angle caused by the interaction of biomolecules on the convergence line of the sensing membrane 6 in the reaction pool, and realize dynamic detection of molecular interaction; The first single-channel sample injection microfluidic system comprises: The liquid reservoir has an injection port, a buffer port and a waste port 301. Figure 3 As shown, the liquid reservoir of the first single-channel injection microfluidic system is the first liquid reservoir 100; A reaction tank, connected to the liquid storage tank, comprising a first reaction tank 103 and a second reaction tank 104 connected in parallel to each other and connected to the liquid storage tank; After the first valve 105 is arranged on the injection flow path 300 of the injection port (the first injection port 101), it is divided into three flow paths respectively connected with the liquid storage tank (the first liquid storage tank 100), the reaction tank (the first reaction tank 103 and the second reaction tank 104) and the waste liquid port 301, the flow path connected with the injection flow path 300 and the liquid storage tank is provided with a second valve 106, the left and right ends of the connection point where the injection flow path 300 and the reaction tank flow path are connected are respectively provided with a third valve 107 and a tenth valve 114, and the upper and lower ends of the connection point and located on the injection flow path 300 are respectively provided with an eleventh valve 115 and a ninth valve 113; The fourth valve 108 and the sixth valve 110 are respectively provided on the flow path connecting the first reaction pool 103 and the second reaction pool 104 with the liquid storage tank, the fifth valve 109 and the eighth valve 112 are respectively provided on the two ends of the first reaction pool 103 and the second reaction pool 104 in parallel, and the seventh valve 111 is provided on the flow path connecting the reaction pool with the waste liquid port 301.

[0019] Since the second single-channel injection microfluidic system has the same structure as the first single-channel injection microfluidic system, after the twelfth valve 205 is set on the injection flow path 300 of the injection port (the second injection port 201) of the second single-channel injection microfluidic system, it is divided into three flow paths respectively connected with the liquid storage tank (the second liquid storage tank 200), the reaction tank (the third reaction tank 203 and the fourth reaction tank 204) and the waste liquid port 301, the flow path connected with the second liquid storage tank 200 is provided with a thirteenth valve 206, the left and right ends of the connection point where the injection flow path 300 is connected with the reaction tank flow path are respectively provided with a fourteenth valve 207 and a twenty-first valve 214, and the upper and lower ends of the connection point and located on the injection flow path 300 are respectively provided with a twenty-second valve 215 and a twenty-first valve 213; The fifteenth valve 208 and the seventeenth valve 210 are respectively provided on the flow paths connecting the third reaction pool 203 and the fourth reaction pool 204 with the second liquid storage pool 200, the sixteenth valve 209 and the nineteenth valve 212 are respectively provided on the two ends of the third reaction pool 203 and the fourth reaction pool 204 in parallel, and the eighteenth valve 211 is provided on the flow path connecting the reaction pool with the waste liquid port 301.

[0020] In the present invention, the plasma resonance sensing detection device comprises a light source 1, a first aspheric lens 2, a polarizer 3, a first cylindrical lens 4, a second cylindrical lens 5, a sensing film 6, a second aspheric lens 7, a third cylindrical lens 8 and a charge coupled device 9; The monochromatic incoherent light emitted by the light source 1 is collimated and expanded into parallel light by the first aspheric lens 2, then forms P polarized light through the polarizer 3, and then converges to the second cylindrical lens 5 through the first cylindrical lens 4, and then converges to the surface of the sensing film 6 arranged at the bottom of the reaction film 10 to form a convergence line. The molecular interaction information on the surface of the sensing film 6 is sensed by the change of the resonance angle, and then reflected from the second cylindrical lens 5, converted into parallel light by the second aspheric lens 7, and then converged into a line by the third cylindrical lens 8. The charge coupled device 9 records the angular spectrum curve of the converged light, and the computer performs data analysis to extract the resonance angle change caused by the interaction of biomolecules on the convergence line at the sensing film 6, so as to realize the dynamic detection of molecular interaction.

[0021] The present invention also provides a method for using the above-mentioned SPR-based microfluidic system, comprising the following steps: Step (1), all flow paths are filled with buffer, the second valve 106, the ninth valve 113, the eleventh valve 115 of the first single-channel sampling microfluidic system and the twelfth valve 205, the twentieth valve 213 and the twenty-second valve 215 of the second single-channel sampling microfluidic system are opened, and the other valves are closed, and buffer is injected from the first buffer port 102 of the first single-channel sampling microfluidic system and the second buffer port 202 of the second single-channel sampling microfluidic system in parallel, and the first liquid reservoir 100 of the first single-channel sampling microfluidic system and the second liquid reservoir 200 of the second single-channel sampling microfluidic system are filled with buffer; Step (2), all valves are closed, the first valve 105, the second valve 106, the twelfth valve 205 and the thirteenth valve 206 of the first single-channel injection microfluidic system and the second single-channel injection microfluidic system are opened, and the buffer is injected from the first buffer port 102 and the second buffer port 202 in parallel to remove bubbles in the flow path; In the present invention, the following steps are also included: Step (3), all valves are closed, the ninth valve 113, the tenth valve 114, and the twentieth valve 213 and the twenty-first valve 214 of the first single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port 102 and the second buffer port 202 in parallel to remove bubbles in the flow path from the first buffer port 102 to the ninth valve 113, then to the tenth valve 114, and finally to the waste liquid port 301.

[0022] In the present invention, the following steps are also included: Step (4), all valves are closed, the first valve 105, the tenth valve 114, the eleventh valve 115 and the twelfth valve 205, the twenty-first valve 214 and the twenty-second valve 215 of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port 102 and the second buffer port 202 in parallel to remove bubbles in the flow path from the tenth valve 114 to the eleventh valve 115 to the first and finally to the waste port 301, as well as bubbles in the flow path from the second buffer port 202 to the twenty-first valve 214 to the twenty-second valve 215 and then to the twelfth valve 205 and finally to the waste port 301.

[0023] In the present invention, the following steps are also included: Step (5), all valves are closed, the tenth valve 114, the third valve 107, the fourth valve 108, the fifth valve 109 and the twenty-first valve 214, the fourteenth valve 207, the fifteenth valve 208 and the sixteenth valve 209 of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port 102 and the second buffer port 202 in parallel to remove bubbles in the flow path from the tenth valve 114 to the third valve 107, the fourth valve 108, the fifth valve 109 and finally to the waste liquid port 301, as well as bubbles in the flow path from the second buffer port 202 to the twenty-first valve 214, the fourteenth valve 207, the fifteenth valve 208 and the sixteenth valve 209 and finally to the waste liquid port 301.

[0024] In the present invention, the following steps are also included: Step (6), all valves are closed, the tenth valve 114, the third valve 107, the eighth valve 112, the sixth valve 110, the fifth valve 109 and the twenty-first valve 214, the fourteenth valve 207, the nineteenth valve 212, the seventeenth valve 210, and the sixteenth valve 209 of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port 102 and the second buffer port 202 in parallel to remove bubbles in the flow path from the tenth valve 114 to the third valve 107, the eighth valve 112, the sixth valve 110, the fifth valve 109, and finally to the waste liquid port 301, as well as bubbles in the flow path from the second buffer port 202 to the twenty-first valve 214, the fourteenth valve 207, the nineteenth valve 212, the seventeenth valve 210, the sixteenth valve 209, and finally to the waste liquid port 301.

[0025] In the present invention, the following steps are also included: Step (7), all valves are closed, the tenth valve 114, the third valve 107, the eighth valve 112, the seventh valve 111 and the twenty-first valve 214, the fourteenth valve 207, the nineteenth valve 212, and the eighteenth valve 211 of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port 102 and the second buffer port 202 in parallel to remove bubbles in the flow path from the tenth valve 114 to the third valve 107, the eighth valve 112, the seventh valve 111, and finally to the waste liquid port 301, as well as bubbles in the flow path from the second buffer port 202 to the twenty-first valve 214, the fourteenth valve 207, the nineteenth valve 212, the eighteenth valve 211 and finally to the waste liquid port 301.

[0026] In the present invention, the following steps are also included: Step (8): injecting the liquid to be tested Close all valves, open the first valve 105, the second valve 106, the tenth valve 114, the ninth valve 113, and the twelfth valve 205, the thirteenth valve 206, the twenty-first valve 214, and the twentieth valve 213 of the second single-channel injection microfluidic system, and inject the sample into the first liquid reservoir 100 of the first single-channel injection microfluidic system and the second liquid reservoir 200 of the second single-channel injection microfluidic system from the first injection port 101 of the first single-channel injection microfluidic system and the second injection port 201 of the second single-channel injection microfluidic system, respectively; Close all valves, open the second valve 106, the eleventh valve 115, the third valve 107, the eighth valve 112, the fourth valve 108, the sixth valve 110, the fifth valve 109 and the thirteenth valve 206, the twenty-second valve 215, the fourteenth valve 207, the nineteenth valve 212, the fifteenth valve 208, the sixteenth valve 209 and the seventeenth valve 210 of the second single-channel injection microfluidic system, inject buffer through the first buffer port 102 and the second buffer port 202, inject the samples in the first liquid storage tank 100 and the second liquid storage tank 200 into the first reaction tank 103 and the second reaction tank 104 of the first single-channel injection microfluidic system and the third reaction tank 203 and the fourth reaction tank 204 of the second single-channel injection microfluidic system, to achieve four-way parallel detection.

[0027] In the present invention, if all valves are closed during sample injection, and then the second valve 106, the eleventh valve 115, the third valve 107, the fourth valve 108, the sixth valve 110, the seventh valve 111 and the thirteenth valve 206, the twenty-second valve 215, the fourteenth valve 207, the fifteenth valve 208, the seventeenth valve 210, and the eighteenth valve 211 of the second single-channel injection microfluidic system are opened at the same time, the function of connecting the first reaction pool 103 in series with the second reaction pool 1041 and the third reaction pool 203 in series with the fourth reaction pool 204 can be achieved.

[0028] In the SPR-based microfluidic system provided by the present invention, liquid path control is all performed in the microfluidic system, the microfluidic system has a small volume, a fast flow path (flow path) switching speed, less mixing and contamination between samples, less sample consumption, less bubbles are generated, and the sensitivity and stability of detection can be improved.

Claims

1. A microfluidic system based on SPR, characterized in that: include: The sampling microfluidic system is a dual-channel sampling microfluidic system formed by connecting a first single-channel sampling microfluidic system and a second single-channel sampling microfluidic system with the same structure in series; Plasma resonance sensing detection device, used to extract the change of resonance angle caused by the interaction of biomolecules on the convergence line of the sensing membrane in the reaction pool, and realize dynamic detection of molecular interaction; The first single-channel sample injection microfluidic system comprises: a liquid reservoir having an injection port, a buffer port, and a waste port; A reaction tank, connected to the liquid storage tank, comprising a first reaction tank and a second reaction tank connected in parallel to each other and connected to the liquid storage tank; After the first valve is arranged on the injection flow path of the injection port, it is divided into three flow paths respectively connected with the liquid storage tank, the reaction tank and the waste liquid port, the second valve is arranged on the flow path connected with the liquid storage tank, the third valve and the tenth valve are arranged on the left and right ends of the connection point where the injection flow path is connected with the reaction tank flow path, respectively, and the eleventh valve and the ninth valve are arranged on the upper and lower ends of the connection point and located on the injection flow path respectively; A fourth valve and a sixth valve are respectively arranged on the flow path connecting the first reaction pool and the second reaction pool with the liquid storage pool, a fifth valve and an eighth valve are respectively arranged at both ends of the first reaction pool and the second reaction pool in parallel, and a seventh valve is arranged on the flow path connecting the reaction pool with the waste liquid port.

2. A SPR-based microfluidic system according to claim 1, characterized in that: The plasma resonance sensing detection device comprises a light source, a first aspheric lens, a polarizer, a first cylindrical lens, a second cylindrical lens, a sensing film, a second aspheric lens, a third cylindrical lens and a charge coupled device; The monochromatic incoherent light emitted by the light source is collimated and expanded into parallel light by the first aspheric lens, then forms P polarized light through the polarizer, and then converges to the second cylindrical lens through the first cylindrical lens, and then converges to the surface of the sensing film to form a convergence line. The molecular interaction information on the surface of the sensing film is sensed by the change of the resonance angle, and then reflected from the second cylindrical lens, converted into parallel light by the second aspheric lens, and then converged into a line by the third cylindrical lens. The charge coupled device records the angular spectrum curve of the converged light, and the computer performs data analysis to extract the resonance angle change caused by the interaction of biomolecules on the convergence line at the sensing film, thereby realizing the dynamic detection of molecular interactions.

3. A method for using a SPR-based microfluidic system according to claim 1 or 2, characterized in that: The steps include: Step (1), all flow paths are filled with buffer, the second valve, the ninth valve, the eleventh valve of the first single-channel sampling microfluidic system and the twelfth valve, the twentieth valve and the twenty-second valve of the second single-channel sampling microfluidic system are opened, and the other valves are closed, and buffer is injected from the first buffer port of the first single-channel sampling microfluidic system and the second buffer port of the second single-channel sampling microfluidic system in parallel, and the first liquid reservoir of the first single-channel sampling microfluidic system and the second liquid reservoir of the second single-channel sampling microfluidic system are filled with buffer; Step (2), all valves are closed, the first valve, the second valve, the twelfth valve and the thirteenth valve of the first single-channel sampling microfluidic system and the second single-channel sampling microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path.

4. The method for using a microfluidic system based on SPR according to claim 3, characterized in that: The following steps are also included: Step (3), all valves are closed, the ninth valve, the tenth valve, and the twentieth valve and the twenty-first valve of the first single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the first buffer port to the ninth valve, then to the tenth valve, and finally to the waste port.

5. The method for using a microfluidic system based on SPR according to claim 3, characterized in that: The following steps are also included: Step (4), all valves are closed, the first valve, the tenth valve, the eleventh valve and the twelfth valve, the twenty-first valve and the twenty-second valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the eleventh valve to the first and finally to the waste port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve to the twenty-second valve and then to the twelfth valve and finally to the waste port.

6. The method for using a microfluidic system based on SPR according to claim 3, characterized in that: The following steps are also included: Step (5), all valves are closed, the tenth valve, the third valve, the fourth valve, the fifth valve and the twenty-first valve, the fourteenth valve, the fifteenth valve and the sixteenth valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the third valve, the fourth valve, the fifth valve and finally to the waste port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve, the fourteenth valve, the fifteenth valve and the sixteenth valve and finally to the waste port.

7. The method for using a microfluidic system based on SPR according to claim 3, characterized in that: The following steps are also included: Step (6), all valves are closed, the tenth valve, the third valve, the eighth valve, the sixth valve, the fifth valve and the twenty-first valve, the fourteenth valve, the nineteenth valve, the seventeenth valve and the sixteenth valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the third valve, the eighth valve, the sixth valve, the fifth valve and finally to the waste liquid port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve, the fourteenth valve, the nineteenth valve, the seventeenth valve, the sixteenth valve and finally to the waste liquid port.

8. The method for using a SPR-based microfluidic system according to claim 3, characterized in that: The following steps are also included: Step (7), all valves are closed, the tenth valve, the third valve, the eighth valve, the seventh valve and the twenty-first valve, the fourteenth valve, the nineteenth valve and the eighteenth valve of the second single-channel injection microfluidic system are opened, and buffer is injected from the first buffer port and the second buffer port in parallel to remove bubbles in the flow path from the tenth valve to the third valve, the eighth valve, the seventh valve and finally to the waste port, as well as bubbles in the flow path from the second buffer port to the twenty-first valve, the fourteenth valve, the nineteenth valve, the eighteenth valve and finally to the waste port.

9. The method for using a SPR-based microfluidic system according to claim 3, characterized in that: The following steps are also included: Step (8): injecting the liquid to be tested Close all valves, open the first valve, the second valve, the tenth valve, the ninth valve, and the twelfth valve, the thirteenth valve, the twenty-first valve, and the twentieth valve of the second single-channel injection microfluidic system, and inject the sample into the first liquid reservoir of the first single-channel injection microfluidic system and the second liquid reservoir of the second single-channel injection microfluidic system from the first injection port of the first single-channel injection microfluidic system and the second injection port of the second single-channel injection microfluidic system, respectively; Close all valves, open the second valve, the eleventh valve, the third valve, the eighth valve, the fourth valve, the sixth valve, the fifth valve and the thirteenth valve, the twenty-second valve, the fourteenth valve, the nineteenth valve, the fifteenth valve, the sixteenth valve and the seventeenth valve of the second single-channel injection microfluidic system, inject buffer through the first buffer port and the second buffer port, inject the samples in the first liquid storage tank and the second liquid storage tank into the first reaction tank and the second reaction tank of the first single-channel injection microfluidic system and the third reaction tank and the fourth reaction tank of the second single-channel injection microfluidic system, to achieve four-way parallel detection.

10. The method for using a microfluidic system based on SPR according to claim 9, characterized in that: If during the sample injection process, all valves are closed and the second valve, eleventh valve, third valve, fourth valve, sixth valve, seventh valve and the thirteenth valve, twenty-second valve, fourteenth valve, fifteenth valve, seventeenth valve and eighteenth valve of the second single-channel injection microfluidic system are opened simultaneously, the function of connecting the first reaction pool in series with the second reaction pool 1 and the third reaction pool in series with the fourth reaction pool can be realized.

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