Grating waveguide multi-microchannel detection system

Abstract

The application provides a grating waveguide multi-micro-channel detection system, which comprises a microfluidic chip, a microscope, a measuring device and an analyzing device; the microfluidic chip comprises a microfluidic group, the microfluidic group comprises a first number of microfluids; the microfluid comprises a grating waveguide group and a micro-channel, the grating waveguide group comprises a second number of grating waveguides, the grating waveguide comprises an exit grating, and the exit grating is located below the micro-channel to guide light into the micro-channel in a vertical direction. The application has the beneficial effects that a structure of a light waveguide and a multi-micro-channel integrated matrix is formed, a higher flux analysis performance than a traditional optical system is realized through a multi-microfluid channel and a large-scale matrix light waveguide, a chip-level on-chip optical detection and analysis system of a high-flux biological sample is quickly constructed, and a high-flux chip for biological detection in a micro-nano scale is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a grating waveguide multi-micro-channel detection system, in particular to a grating waveguide multi-micro-channel biological detection system. BACKGROUND

[0002] In modern biochemical analysis process, high-throughput detection equipment has been widely used. These devices mostly use microfluidic technology or micro-well array-based biochips, loaded in high-performance optical systems, to realize the analysis of biological samples such as nucleic acids, proteins, viruses, bacteria, cells, etc. of different sizes. The design of these optical systems is usually based on complex geometric optics, which is large in size, high in cost, requires optical collimation, and has high maintenance cost.

[0003] In the era of precision medicine, miniaturized, high-performance, low-cost and mobile integrated analysis systems have attracted great attention. Especially the concept of lab on chip, after decades of development, based on microfluidic technology, has made great progress in the manipulation of biological samples, but a real lab on chip system still lacks a high-throughput biological sample chip-level on-chip optical detection and analysis integrated system at the micro-nano scale. SUMMARY

[0004] To solve the current problems of modern biochemical analysis instruments, such as large size, high cost, and meet the new requirements of miniaturization, mobility and integration of instruments in the era of precision medicine. The present application produces such a chip-level optical detection and analysis system through integrated circuit mass production process, realizes the functions of traditional optical system through integrated optics or on-chip optical devices, not only can reduce the traditional benchtop or even large optical system to chip size, but also ensure the same or even better analysis performance, realize the high-throughput chip-level optical detection and analysis integrated system of biological samples at the micro-nano scale, and greatly reduce the system cost.

[0005] The present application provides a grating waveguide multi-micro-channel detection system, comprising: a microfluidic chip, a microscope, a measuring device and an analysis device; characterized in that,

[0006] The microfluidic chip comprises a microfluidic group, and the microfluidic group comprises a first number of microfluids;

[0007] The microfluidic chip comprises a grating waveguide group and a microfluidic channel, the grating waveguide group comprises a second number of grating waveguides, the grating waveguide comprises an exit grating, the exit grating is located below the microfluidic channel to guide light into the microfluidic channel in a vertical direction, the microscope is used to collect light signals in the microfluidic channel and transmit the light signals to the measuring device, the measuring device is used to process the light signals and generate analysis signals and transmit the analysis signals to the analysis device, and the analysis device analyzes the analysis signals to form a spectrum.

[0008] The microfluidic chip further comprises: a substrate, a lower cladding layer, a waveguide layer, a protective layer, an upper cladding layer and a channel cover plate arranged in sequence from bottom to top, the waveguide layer is a silicon nitride material, and the waveguide layer is used to form the grating waveguide group; the protective layer is a silicon dioxide material, and is used to cover the grating waveguide group and protect the exit grating.

[0009] The microfluidic channel penetrates through the upper cladding layer to expose the protective layer.

[0010] The channel cover plate covers the microfluidic channel upper opening, and the channel cover plate comprises a liquid injection port used to inject a solution containing biological molecules to be detected into the microfluidic channel.

[0011] The lower cladding layer is silicon dioxide with a thickness of 2-3 μm, and the upper cladding layer is a high-molecular polymer material with a thickness of 15-30 μm, and the microfluidic channel has a width of 10-100 μm.

[0012] Preferably, the grating waveguide group comprises a second number of parallel grating waveguides to guide light into the microfluidic channel, and the grating waveguide has a width of 300-600 nm.

[0013] Preferably, the waveguide layer has a refractive index of 1.75-2.2.

[0014] Preferably, the waveguide layer has a thickness of 150 nm-1000 nm.

[0015] Preferably, the light guide structure is further provided, and the light guide structure is optically connected to the grating waveguide group.

[0016] Preferably, the light guide structure comprises a light splitting structure.

[0017] Preferably, the light splitting structure is used to guide a second number of first light guides upward from a second number of first light guides.

[0018] Preferably, the grating waveguide is a coupled grating waveguide.

[0019] The coupled grating waveguide further includes an incident grating that guides light from above the upper cladding into the coupled grating waveguide until it is guided upward in the vertical direction into the microchannel; the protective layer covers and protects the incident grating, the waveguide layer has a thickness of 150nm-1000nm, and the coupled grating waveguide has a width of 300-600nm.

[0020] Preferably, the substrate is a silicon substrate.

[0021] Preferably, the refractive index of the waveguide layer is 1.75-2.2.

[0022] Beneficial effects: It forms an integrated matrix structure of optical waveguide and multi-microfluidic channel, and achieves higher throughput analysis performance than traditional optical systems through multi-microfluidic channels and large-scale matrixed optical waveguides. It can quickly build a chip-level on-chip optical detection and analysis system for high-throughput biological samples, and realize high-throughput chip for biological detection at the micro-nano scale. Attached Figure Description

[0023] Appendix Figure 1 This is a side view of the grating waveguide multi-microfluidic detection system of the present invention;

[0024] Appendix Figure 2 yes Figure 1 A side view of a microfluidic in a chip;

[0025] Appendix Figure 3 yes Figure 2 Top view;

[0026] Appendix Figure 4 This is a schematic diagram of the light guide structure;

[0027] Appendix Figure 5 yes Figure 4 Structural diagram

[0028] Appendix Figure 6 yes Figure 4 or Figure 5 A magnified view of A in the middle;

[0029] Appendix Figure 7 yes Figure 4 or Figure 5 A magnified view of B in the middle;

[0030] Appendix Figure 8 yes Figure 7 Cross-sectional view;

[0031] Appendix Figure 9 This is a schematic diagram of a coupled grating waveguide multi-channel detection system. Detailed Implementation

[0032] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0033] In the drawings, the proportions of the sizes of layers and regions are not actual proportions for the sake of convenience in description. When a layer (or film) is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or an intervening layer can also be present. Also, when a layer is referred to as being "under" another layer, it can be directly under the other layer, and one or more intervening layers can also be present. In addition, when a layer is referred to as being between two layers, it can be the only layer between the two layers, or one or more intervening layers can also be present. The same reference numbers are used in different drawings to represent the same elements. In addition, when two components are referred to as being "connected" to each other, the physical connection includes, unless the specification explicitly defines otherwise, but is not limited to, an electrical connection, a contact connection, a wireless signal connection.

[0034] The present application proposes a vertical grating waveguide integrated module scheme with a microfluidic channel, and a matrix scheme for a multi-microfluidic channel system, to quickly construct a high-throughput biological sample chip-level on-chip optical detection and analysis integrated system under micro / nano scale. The vertical grating waveguide refers to a grating waveguide that guides light in a vertical direction upward into a microfluidic channel

[0035] A grating waveguide multi-microfluidic channel detection system, as shown in Figures 1-4 includes a microfluidic chip 1, a microscope 3, a measuring device 4, and an analysis device 5.

[0036] The microfluidic chip 1 includes a microfluidic group (not shown), which includes a first number of microfluidics (not shown), as shown in Figure 1 The first number is m.

[0037] The microfluidics include a grating waveguide group and a microfluidic channel, as shown in Figure 2 One microfluidic includes a grating waveguide group 131 and a microfluidic channel 201; the grating waveguide group 131, 132…13m each includes a second number of grating waveguides, as shown in Figure 2 and Figure 3 The second number is n, and the grating waveguide group 131 includes n grating waveguides 1311, 1312…131n to form an n*m matrix detection system.

[0038] The grating waveguide 1311, 1312…131n includes an exit grating 1310 located below the microfluid channel 201 to guide light vertically upward into the microfluid channel 201, providing a new design scheme and idea for different complex integrated structures, and the exit grating of different exit directions can be designed, increasing the flexibility of the detection means, the microscope 3 is used to collect the light signal in the microfluid channel 201, 202…20m and transmit the light signal to the measuring device 4, the measuring device 4 is used to process the light signal and generate an analysis signal and transmit the analysis signal to the analysis device 5, and the analysis device 5 analyzes the analysis signal to form a spectrum; It should be noted that "guiding light vertically upward" in the above can be strictly vertically upward, or obliquely upward, which is not limited in the present application.

[0039] The microfluidic chip 1 further comprises: a substrate 11, a lower cladding layer 141, a waveguide layer 13, a protective layer 12, an upper cladding layer 142 and a channel cover plate 15 arranged in turn from bottom to top, the waveguide layer 13 is a silicon nitride material, and the waveguide layer 13 is used to form the grating waveguide group 131, 132…13m; the protective layer is a silicon dioxide material, has light transmission, and is used to cover the grating waveguide group 131, 132…13m and protect the exit grating 1310;

[0040] The microfluid channel 201, 202…20m penetrates the upper cladding layer 142 to expose the protective layer 12;

[0041] The channel cover plate 15 covers the upper opening of the microfluid channel 201, 202…20m, and the channel cover plate 15 includes a liquid injection port 151, 152…15m for injecting a solution containing a biological molecule to be detected into the microfluid channel 201, 202…20m; It should be noted that it also includes a liquid outlet (not shown) to form a circulation system corresponding to the liquid injection port 151, 152…15m, and the liquid outlet can be an opening on the channel cover plate 15; The liquid outlet can also be an opening at both ends of the microfluid channel, which is not limited in the present application.

[0042] The lower cladding layer 141 is silicon dioxide with a thickness of 2-3 μm, the upper cladding layer 142 is a high molecular polymer material with a thickness of 15-30 μm, and the microfluid channel 201, 202…20m has a width of 10-100 μm; The structure of the integrated matrix of the grating waveguide and the multi-microfluid channel quickly constructs the chip-level on-chip optical detection and analysis integrated system of high-throughput biological samples under micro-nano scale.

[0043] It should be noted that the first number m microfluidics can form a microfluidic group, and a third number of microfluidic groups can be constructed to form a microfluidic matrix, where the third number is k. Then, the total number of grating waveguides can form an n*m*k matrix detection system. This forms a structure that integrates grating waveguides and multiple microchannels into a matrix, enabling the rapid construction of a chip-level on-chip optical detection and analysis integrated system for high-throughput biological samples at the micro-nano scale.

[0044] It should be noted that the grating waveguide group includes a second number n mutually parallel grating waveguides, such as... Figure 1 As shown, the grating waveguide group 131 includes a second number of n parallel grating waveguides 1311, 1312...131n to guide light upward in a vertical direction into the microchannel 201. The width of the grating waveguides 1311, 1312...131n is 300-600nm.

[0045] Depending on the direction of the light source introduced into the grating waveguide group 131, such as: Figures 1-2 The light source is introduced from the left end by the grating waveguide group 131, and Figure 8 The light source is introduced from the upper cladding 142. In multi-microchannel systems, especially in matrix-based detection systems, the former requires structural additions such as... during the fabrication of the matrix chip. Figure 4 The light guide structure shown in diagram 6 is not required for the latter. The following section will discuss this further. Figures 1-7 Explanation of the light guide structure 6:

[0046] like Figure 1 and Figure 3 As shown, the grating waveguide group 131 includes a second number, such as n, of parallel grating waveguides 1311, 1312…131n. The light guiding structure 6 includes a second number of n first light guides 61, used to optically connect with the second number of grating waveguides in the grating waveguide group 131. That is, the light guiding structure 6 optically connected to it requires corresponding n first light guides 61 to guide light horizontally into the grating waveguides and ultimately vertically upward into the microchannel 201. In actual detection, for biomolecules containing different labels in the microchannel 201, the grating waveguides 1311, 1312…131n, connected one-to-one with the n light guides, can respectively guide light of different wavelengths λ1, λ2…λn vertically upward into the microchannel 201. By using light of different wavelengths to excite the labeled biomolecules 21, these biomolecules can be recognized simultaneously, without being detected in the grating waveguide 1311… The non-excited biomolecules 20 introduced into the excitation light field 1312…131n will not be recognized. The non-excited biomolecules 20 are unlabeled normal biomolecules or labeled biomolecules located outside the light field and not excited; among them, such as Figure 3 As shown, the width of the grating waveguides 1311, 1312...131n is 300-600nm.

[0047] As shown in Figures 1-2 , the waveguide layer 13 has a thickness of 150nm-1000nm, that is Figures 1-2 the horizontal part of the grating waveguide 1311, 1312…131n in the above-mentioned grating waveguide n*m matrix has a thickness of 150nm-1000nm.

[0048] As shown in Figure 1 and Figure 4 , the light guide structure 6 includes a trunk light guide 60, and a first light guide group 601, a second light guide group 602…a kth light guide group drawn from the trunk light guide 60 to respectively introduce light sources to the k microfluid groups. Wherein, the light guide structure 6 is optically connected with the grating waveguide group 131 through the first light guide group 601, and then optically connected with all grating waveguide groups 132..13m in the same microfluid group along the waveguide layer 13, without the need to match a separate light guide structure for each grating waveguide group, saving process and reducing the complexity of the structure.

[0049] For the above-mentioned grating waveguide n*m matrix detection system: the light guide structure 6 includes n first lights 61 in the trunk light guide 60 to respectively transmit light with wavelengths of λ1, λ2, λ3…λn to the grating waveguides 1311, 1312…131n in the grating waveguide group 131, to all grating waveguide groups 132..13m in the same microfluid group, in which case the n first lights 61 in the trunk light guide 60 constitute the first light guide group 601.

[0050] For the above-mentioned grating waveguide n*m*k matrix detection system: the first light guide group 601, the second light guide group 602…the kth light guide group drawn from the trunk light guide 60 to respectively introduce light sources to the k microfluid groups; the first light 61 in the trunk light guide 60 has a light splitting and crossing situation, so for Figure 1 The multi-channel monitoring system matrix integrated grating waveguide multi-microfluidic chip needs to design a specific light guide structure 6, which provides a light guide structure 6 as shown in Figures 4-5 , which includes a trunk light guide 60, and a light guide group 601, 602…60k drawn from the trunk light guide 60; wherein the trunk light guide 60 includes n first lights 61, which transmit light with wavelengths of λ1, λ2, λ3…λn to respectively transmit to the grating waveguides 1311, 1312…131n in the grating waveguide group 131. Wherein, the drawing nodes of the light guide group 601, 602…60k drawn from the trunk light guide 60, and the crossing nodes of the second light 62 drawn and the first light 61 in the trunk light guide 60 (and the first light 61 in the same light guide group) need to be specially designed; as shown in Figures 5-8As shown, the light guide groups 601, 602…60k adopt the light splitting structure A to guide out from the trunk light guide 60, and the light splitting structure A is shown in the following figure. Figure 5 As shown, the light splitting structure A is used to guide out the second light guide 62 from the first light guide 61 in the trunk light guide 60, and the light splitting structure A is shown in the following figure. Figures 6-7 As shown, the cross-layer structure B of the cross node B is shown in the following figure, and the first light guide 61 (the first light guide 61 in the trunk light guide 60 or the first light guide 61 in the same light guide group) and the second light guide 62 cross through the cross-layer structure B; the cross-layer structure B includes the first light guide overlapping area 610 and the second light guide overlapping area 620; the first light guide 61 is disconnected at the cross, and two acute light guide end faces are formed at the opposite ends of the disconnection; the second light guide 62 forms an acute light guide leading face matching the acute light guide end face at the cross; the first light guide overlapping area 610 includes the acute light guide end face and the acute light guide leading face matching the acute light guide end face, and the distance between them is less than 1 μm; the second light guide overlapping area 620 includes the acute light guide end face and the acute light guide leading face matching the acute light guide end face, and the distance between them is less than 1 μm; that is, the first light guide 61 is disconnected at the cross, and each of the two acute light guide end faces is formed at the opposite ends of the disconnection; the second light guide 62 guided out from the trunk light guide 60 forms two acute light guide leading faces matching the above two acute light guide end faces at the cross, and the distance between them is less than 1 μm, thereby forming the first light guide overlapping area 610 and the second light guide overlapping area 620; the light from the disconnected end of the first light guide 61 enters the second light guide 62 through the first light guide overlapping area 610, and then enters the other disconnected end of the first light guide 61 through the second light guide overlapping area 620.

[0051] It should be noted that for the above-mentioned total number of grating waveguides forming an n*m*k matrix detection system, the light splitting structure A can be used to continue to transmit the light source from the second to the kth microfluid group on the leftmost first light guide 61. As shown in the following figure. Figure 4 As shown, the light splitting structure A is used to guide out the second number of second light guides 62 from the second number of first light guides 61, and specifically, the second number n of second light guides 62 are guided out vertically upward from the second number n of first light guides 61 and are folded in the horizontal direction of the first light guide 61 in the trunk light guide 60 at the corresponding position of the next microfluid group 1’ to form the second number n of first light guides 61 in the second light guide group 602, so as to transmit the light source to the next microfluid group 1’, and so on, until the kth microfluid group transmits the light source.

[0052] The grating waveguide multi-microfluid channel detection system for introducing the light source from above the upper cladding layer 142 does not need special light guide structure design: as shown in the following figure. Figure 9As shown, at one end of the waveguide layer 13 (as shown on the left), there is a second number n of silicon nitride material incident gratings 1310', which form coupled grating waveguides with the second number n of the nearest grating waveguide group 131 in the microfluidic. The light above the channel cover plate 15 is guided into the waveguide layer 13 and transmitted along the waveguide layer 13 to all microfluids in the same microfluidic group. The light is guided vertically upward into the microfluidic channels 201, 202...20m. The upper cladding layer 142 above the incident grating 1310', the channel cover plate 15, and the protective layer 12 are all transparent. The protective layer 12 is made of silicon dioxide and is used to cover the grating waveguide group 131, 132...13n and protect the output grating 1310.

[0053] like Figure 3 As shown, a microfluidic system includes a grating waveguide assembly 131 comprising several, such as n, mutually parallel coupled grating waveguides to guide light vertically upward into the microchannel 201. In actual detection, for biomolecules containing different labels in the microchannel 201, the coupled grating waveguides can guide light with wavelengths λ1, λ2…λn vertically upward into the microchannel 201, respectively. By using light of different wavelengths to excite labeled biomolecules 21 with different labels, these biomolecules can be recognized simultaneously. Unexcited biomolecules 20 not in the excitation light field introduced by the coupled grating waveguides will not be recognized. Unexcited biomolecules 20 are unlabeled normal biomolecules or labeled biomolecules located outside the light field and not excited; wherein, such as… Figure 4 As shown, the width of the coupled grating waveguide is 300-600 nm, wherein, as... Figure 9 As shown, the thickness of the waveguide layer 13 is 150nm-1000nm, that is, the thickness of the horizontal part of the grating waveguide group is 150nm-1000nm.

[0054] In this invention, the substrate 11 is a silicon substrate; preferably, the substrate 11 is a 4, 8, or 12-inch silicon wafer.

[0055] In this invention, the polymer material is SU-8 resin, polyimide, polydimethylsilane, polyethylene, or styrene.

[0056] In this invention, the flow channel cover 15 is made of PDMS, quartz, or the aforementioned polymer materials.

[0057] In the present application, the silicon nitride waveguide layer 13 is a 150nm-1000nm-thick silicon nitride film layer formed at a low temperature of 25-150℃; the refractive index of the silicon nitride film is 1.75-2.2. It should be noted that the silicon nitride film can be a film with uniform refractive index or a film with non-uniform refractive index, such as a silicon nitride film with a refractive index layered structure.

[0058] Circulating tumor cells are a general term for various tumor cells that have detached from tumor tissues and entered the human blood circulation system. By detecting trace amounts of circulating tumor cells in peripheral blood and monitoring the trend of changes in the types and quantities of the circulating tumor cells, the tumor dynamics can be monitored in real time, the treatment effect can be evaluated, and real-time individual treatment can be achieved. Figure 1 In combination with the above, one embodiment of detecting circulating tumor cells by using the grating waveguide total number of the grating waveguide multi-microfluidic detection system to form an n*m*k matrix detection system is described below, and the main steps are as follows:

[0059] Step 1: The immune magnetic bead technology (such as immune magnetic bead positive sorting) or microfluidic technology is used to sort and enrich the possible various tumor cells in the collected m*k patient blood samples to obtain a solution containing circulating tumor cells, or the patient blood samples can be directly used;

[0060] Step 2: Antibody groups capable of specifically binding to the surface antigens of various tumor cells or aptamer groups capable of binding to the surface of various tumor cells are added to the solution containing circulating tumor cells or the blood samples, and the antibody groups and the aptamer groups are modified with labels, wherein the labels modified on the antibodies or aptamers combined with specific tumor cells are unique, so as to obtain a solution or blood sample containing labeled circulating tumor cells; the labels are n kinds, and the labels can be target probes of fluorescent molecules;

[0061] Step 3: As shown in Figure 1 , the m*k solutions or blood samples obtained in Step 2 are respectively added from the liquid injection ports 151, 152, …, 15m (not completely listed, and the total number of the liquid injection ports is m*k) into the microfluidic channels 201, 202, …, 20m (not completely listed, and the total number of the microfluidic channels is m*k), and the light guide groups 601, 602, …, 60k (not completely listed, and the total number of the light guide groups is k) guide n different wavelengths of light corresponding to the n kinds of labels into the first number m (all) of grating waveguide groups 131, 132, …, 13m (not completely listed, and the total number of the grating waveguide groups is m*k) in the corresponding microfluidic groups along the waveguide layer 13, and the second number n (all) of grating waveguides (such as Figure 1 and Figure 4As shown, the n grating waveguides 1311, 1312…131n in the grating waveguide group 131 (not completely listed, the total number of grating waveguides is n*m*k) are introduced into the micro flow channels 201, 202…20m in the vertical direction upwards, the above-mentioned labeled biomolecules 21 containing different fluorescent molecules are the circulating tumor cells excited by the different wavelengths of light to emit specific wavelength fluorescence, the microscope 3 is used to collect the specific wavelength fluorescence (light signal) and transmit to the measuring device 4, the measuring device 4 processes the collected specific wavelength fluorescence (light signal) and generates the to-be-analyzed signal and transmits the to-be-analyzed signal to the analysis device 5, the analysis device 5 analyzes the to-be-analyzed signal to form the spectrum of the specific wavelength fluorescence, by reading the spectrum, the type of circulating tumor cells in the solution or blood sample can be determined, a plurality of tumor circulating cells of different patients can be detected at a time, a high-throughput chip for detecting a plurality of tumor cells under micro-nano scale is realized, so that the tumor dynamics can be monitored in real time, the treatment effect can be evaluated, and real-time individual treatment can be realized.

[0062] The application provides a grating waveguide multi-micro flow channel detection system, which has the beneficial effects of forming a structure of integrated matrix of optical waveguide and multi-micro flow channel, realizing higher-throughput analysis performance than a traditional optical system through the multi-micro flow channel and large-scale matrix optical waveguide, quickly constructing a chip-level on-chip optical detection and analysis system of high-throughput biological samples, and realizing a high-throughput chip for biological detection under micro-nano scale.

[0063] The above only describes the preferred embodiments of the application, and it should be noted that, for those skilled in the art, without departing from the principles of the application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the application.

Claims

1. A grating waveguide multi-microfluidic channel detection system, comprising: Microfluidic chip, microscope, measuring device and analyzing device; characterized in that The microfluidic chip comprises a microfluidic group, the microfluidic group comprises a first number of microfluids; The microfluidic chip comprises a microfluidic group, the microfluidic group comprises a first number of microfluids; The microfluidic chip comprises a microfluidic group, the microfluidic group comprises a first number of microfluids; The microfluidic chip further comprises: a substrate, a lower cladding layer, a waveguide layer, a protective layer, an upper cladding layer and a flow channel cover plate arranged in turn from bottom to top, the waveguide layer is a silicon nitride material, and the waveguide layer is used to form the grating waveguide group; the protective layer is a silicon dioxide material, and is used to cover the grating waveguide group and protect the exit grating; The microfluidic channel penetrates through the upper cladding layer to expose the protective layer; The flow channel cover plate covers the microfluidic channel opening, and the microfluidic channel cover plate comprises a liquid injection port used to inject a solution containing biological molecules to be detected into the microfluidic channel; The lower cladding layer is silicon dioxide with a thickness of 2-3 µm, the upper cladding layer is a high-molecular polymer material with a thickness of 15-30 µm, and the microfluidic channel has a width of 10-100 µm; The refractive index of the waveguide layer is 1.75-2.2; The waveguide layer has a thickness of 150 nm-1000 nm; 2. The system of claim 1, wherein, Further comprising a light guide structure, the light guide structure is optically connected with the grating waveguide group, the light guide structure comprises a trunk light guide and a light guide group led out from the trunk light guide, the trunk light guide comprises n first light guides, and the light guides transmit light waves with wavelengths of λ1, λ2, λ3…λn respectively to transmit to the grating waveguides in the grating waveguide group; the light guide group adopts a light splitting structure to lead out from the trunk light guide, and a second light guide in the light guide group is led out from the first light guide in the trunk light guide; the first light guide and the second light guide cross through a cross-layer structure, the cross-layer structure comprises a first light guide overlapping area and a second light guide overlapping area; the first light guide is disconnected at the cross, and two acute-angle light guide end faces are formed at opposite ends of the disconnection; the second light guide forms an acute-angle light guide leading surface matched with the acute-angle light guide end face at the cross; the first light guide overlapping area comprises the acute-angle light guide end face and the acute-angle light guide leading surface matched with the acute-angle light guide end face, and the distance between them is less than 1 µm; the second light guide overlapping area comprises the acute-angle light guide end face and the acute-angle light guide leading surface matched with the acute-angle light guide end face, and the distance between them is less than 1 µm.

3. The system of claim 1, wherein, The grating waveguide group comprises a second number of parallel grating waveguides to guide light into the microfluidic channel, and the width of the grating waveguide is 300-600 nm. The grating waveguide is a coupled grating waveguide. The coupling grating waveguide further comprises an incident grating for guiding light above the upper cladding into the coupling grating waveguide until the microfluid channel is guided upward in the vertical direction; the protective layer covers and protects the incident grating, the waveguide layer has a thickness of 150-1000 nm, and the coupling grating waveguide has a width of 300-600 nm.

4. The system of claim 1, wherein, The substrate is a silicon substrate.

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