A diffraction imaging molecular detection device and its application

Abstract

The present invention discloses a diffraction imaging molecular detection device and its application. The diffraction imaging molecular detection device of the present invention comprises a light source unit, an LSPR sensing unit, a spectroscopic unit and a display unit; the LSPR sensing unit is arranged between the light source unit and the spectroscopic unit, and the three are parallelly distributed on the same optical path; the spectroscopic unit is a curved holographic grating; the light source unit provides a light signal for the detection device, and the light penetrates the sample solution to be tested on the LSPR sensing unit, and then passes through the LSPR sensing unit to reach the spectroscopic unit, and the spectroscopic unit splits the light signal and projects it on the display unit to form a diffraction image, without using a high-sensitivity, high-resolution spectrometer, and the process of molecular adsorption change at the sensing unit interface can be obtained by only analyzing the relationship between the pixel position and intensity distribution in the diffraction image.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and more specifically, to a diffraction imaging molecule detection device and applications thereof. Background Art

[0002] Since the metasurfaces of metal and dielectric nanophotonic structures have the unique ability to manipulate light scattering in the subwavelength range, they are widely used in the field of nanophotonics. Moreover, the localized surface plasmon resonance effect is a unique optical property of metal nanostructures. When a beam of light is irradiated onto the metasurface, resonance will occur when the frequency of the light is the same as the vibration frequency of the free electrons on the surface of the metal nanoparticles, making the metal nanostructure very sensitive to the refractive index changes of the surrounding environment. Therefore, metal nanostructures are very suitable for sensing the refractive index changes of thin layer attachments on the metasurface nanostructures to detect the changes of the attachment molecules in the solution and the changes in the adsorption of the sensor interface.

[0003] However, when the amount of attachments on the metasurface nanostructure is very small, it is difficult to detect the changes in the attachment molecules in the solution and their adsorption changes at the sensor interface using conventional spectrometers. A high-sensitivity and high-resolution spectrometer is required to record the changes in the attachments, but such spectrometers are usually bulky, expensive and complex, which seriously hinders the application of metasurfaces in molecular sensing and many other daily detection scenarios. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects and shortcomings of the prior art that a high-sensitivity, high-resolution spectrometer is needed to detect changes in trace attachment molecules in a solution and their adsorption changes on a sensor interface, and to provide a diffraction imaging molecule detection device, which combines a plasma metasurface as an LSPR sensing unit and a curved holographic grating as a spectroscopic unit. After the detection light passes through a sample solution to be tested and a sensing LSPR sensing unit in sequence, it reaches the spectroscopic unit, and a diffraction image can be formed only after spectroscopic processing by the spectroscopic unit. Without the need to use an expensive and complex high-resolution spectrometer, the changes in molecules in a solution and their adsorption changes on the sensor unit interface can be detected.

[0005] Another object of the present invention is to provide a molecular detection device based on a monochrome camera.

[0006] Another object of the present invention is to provide a diffraction imaging molecule detection device for use in detecting the refractive index of a solution.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] A diffraction imaging molecular detection device comprises a light source unit 1, an LSPR sensor unit 2, a spectroscopic unit 3 and a display unit 4; the LSPR sensor unit 2 is arranged between the light source unit 1 and the spectroscopic unit 3, and the three are horizontally distributed on the same optical path; the spectroscopic unit 3 is a curved holographic grating; the light source unit 1 provides a light signal for the detection device, and after the light penetrates the solution to be tested on the LSPR sensor unit 2, it passes through the LSPR sensor unit 2 to reach the spectroscopic unit 3, and the spectroscopic unit 3 splits the light signal and projects it on the display unit 4 to form a diffraction image.

[0009] The diffraction imaging molecular detection device of the present invention combines an LSPR sensing unit (plasma metasurface) and a spectroscopic unit (curved holographic grating). After the detection light passes through the sample solution to be tested and the sensing LSPR sensing unit in sequence, it reaches the spectroscopic unit, and is projected onto a display unit (light screen) after being spectroscopically processed by the spectroscopic unit to form a diffraction image. After analyzing the changes in the pixel position and the maximum value of the intensity (brightness) in the diffraction image, the change in the refractive index of the sample solution to be tested can be obtained, and then the process of adsorption change of the sample molecules to be tested on the interface of the LSPR sensing unit can be obtained.

[0010] A method for preparing a curved holographic grating comprises the following steps:

[0011] S1. Using indium tin oxide conductive glass as a carrier, first nanoimprinting and then electroplating to form a copper nanograting;

[0012] S2. The polyvinyl alcohol aqueous solution is evenly coated on the copper nanograting in S1, and then dried to form a copper nanograting / polyvinyl alcohol composite film;

[0013] S3. The copper nanograting / polyvinyl alcohol composite film in S2 is fixed to the convex side of the spherical lens and heated;

[0014] S4. By removing the polyvinyl alcohol from the copper nanograting / polyvinyl alcohol composite film, a curved holographic grating can be obtained.

[0015] The purpose of the drying treatment in step S2 of the preparation method of the curved holographic grating of the present invention is to remove the solvent water in the polyethylene aqueous solution and solidify it to form a continuous film. The degree of drying can be to ensure that the copper nanograting / polyvinyl alcohol composite film is completely separated from the indium tin oxide conductive glass; and the purpose of the heating treatment in step S3 is to ensure that the copper nanograting / polyvinyl alcohol composite film is tightly and bubble-freely attached to the convex side of the spherical lens, so that after the polyethylene alcohol is removed in step S4, the copper nanograting can be completely transferred to the convex side of the spherical lens to form a curved holographic grating, wherein the specific temperature of the heating treatment can be controlled at about 100°C, and the copper nanograting is adsorbed on the convex side of the spherical lens by electrostatic adsorption.

[0016] It should be noted that, in a specific embodiment, the period of the copper nanograting of the present invention is 606nm, and the focal length of the spherical lens is 14mm. The period of the copper nanograting and the focal length of the spherical lens will affect the reception of the diffraction image by the display unit 4. In specific applications, those skilled in the art can change the period of the copper nanograting according to the grating equation sinθ=kλ / Λ, where θ is the diffraction angle, λ is the wavelength of the incident light, and Λ is the period of the grating. The diffraction angle will also change accordingly. At this time, a clear diffraction image can be obtained by adjusting the inclination angle of the display unit.

[0017] In a specific embodiment, the mass percentage of polyvinyl alcohol in the polyvinyl alcohol aqueous solution in S2 of the present invention is 8% to 10%.

[0018] When the mass percentage of polyvinyl alcohol in the polyvinyl alcohol aqueous solution described in S2 of the present invention is 8% to 10%, a continuous copper nanograting / polyvinyl alcohol composite film is easily formed after spin coating and drying, so that the copper nanograting / polyvinyl alcohol composite film is completely separated from the indium tin oxide conductive glass carrier, thereby ensuring the integrity of the copper nanograting in the curved holographic grating, improving the spectroscopic effect of the curved holographic grating when used as the spectroscopic unit 3, and improving the clarity of the diffraction image.

[0019] Preferably, the weight average molecular weight of the polyvinyl alcohol in S2 is ≤110,000.

[0020] Preferably, the weight average molecular weight of the polyvinyl alcohol in S2 is 80,000-110,000.

[0021] Specifically, the polyvinyl alcohol of the present invention is type 1788, and when its weight average molecular weight is 80,000 to 110,000, it can form a continuous polyvinyl alcohol film to ensure the integrity of the copper nanograting and improve the clarity of the diffraction image; it can also ensure that less time is required for subsequent water dissolution to remove the polyvinyl alcohol.

[0022] Preferably, the copper nanograting / polyvinyl alcohol composite film in S2 has a thickness of 10 to 20 μm.

[0023] When the copper nano-grating / polyvinyl alcohol composite film has a thickness of 10 to 20 μm, it can be better separated from the indium tin oxide conductive glass carrier and the time required for subsequent removal of the polyvinyl alcohol by water dissolution can be shortened.

[0024] Preferably, the convex side of the spherical lens in S3 is subjected to plasma cleaning. Compared with other cleaning methods, plasma cleaning can better remove impurities on the surface of the curved lens.

[0025] Preferably, the light source unit 1 is a monochromatic light source.

[0026] The present invention also protects a monochrome camera-based molecular detection device, which is composed of a monochrome camera and the above-mentioned diffraction imaging molecular detection device and monochrome camera;

[0027] The diffraction imaging molecular detection device comprises a light source unit 1, an LSPR sensor unit 2, a spectroscopic unit 3 and a display unit 4; the LSPR sensor unit 2 is arranged between the light source unit 1 and the spectroscopic unit 3, and the three are horizontally distributed on the same optical path; the spectroscopic unit 3 is a curved holographic grating; the light source unit 1 provides a light signal for the detection device, and the light penetrates the solution to be tested on the LSPR sensor unit 2, and then passes through the LSPR sensor unit 2 to reach the spectroscopic unit 3, and the spectroscopic unit 3 splits the light signal and projects it on the display unit 4 to form a diffraction image;

[0028] The monochrome camera is used to record the diffraction image detected by the diffraction imaging molecule detection device.

[0029] The application of a diffraction imaging molecule detection device in detecting the refractive index of a solution is also within the protection scope of the present invention.

[0030] Specifically, taking the process of detecting the interaction between antigen and antibody molecules in an aqueous solution and the process of adsorption changes at the sensing interface as an example, 11-mercaptoundecanoic acid (MUA) is first added to the surface of the LSPR sensor to modify it, and a thiol-gold combined chemical bond for fixing the antibody molecules is formed on the gold nanoparticles on the surface of the LSPR sensor, and then an antigen solution is added, and the antigen combines with the MUA on the surface of the gold nanoparticles. After the antibody is added, the antibody specifically binds to the antigen, thereby changing the free electrons on the surface of the gold nanoparticles, thereby causing the refractive index of the surface of the LSPR sensor to change. At this time, the light reaches the curved grating through the solution after the refractive index change. The curved grating has both the diffraction function of the grating and the function of the lens to converge or diffuse the incident light. After the light that arrives is split and focused, a diffraction image is generated on the display unit (light screen), and then the position-intensity (brightness) curve can be obtained by averaging the intensity (brightness) of each row of pixels on the diffraction image. Among them, the average value of the intensity (brightness) is obtained by summing the brightness values ​​of each pixel in a row of pixels at different positions and dividing it by the number of pixels in the row (such as Figure 3 When the concentration of the antibody is changed, different position-intensity (brightness) curves are obtained. By analyzing the distribution relationship between the pixel position and intensity (brightness) in the diffraction image, the process of molecular adsorption change at the sensor unit interface can be obtained.

[0031] In a specific embodiment, the application of the diffraction imaging molecular detection device of the present invention in detecting the change process of biological molecules in a solution and the adsorption change process on the sensor interface includes the following steps:

[0032] S1. The sample solutions of different concentrations are respectively added dropwise to the LSPR sensor unit 2 of the diffraction imaging molecular detection device to obtain different diffraction images projected on the display unit 4;

[0033] S2. The position-intensity curve of the diffraction image can be obtained by averaging each row of pixels at different positions of different diffraction images in S1.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a diffraction imaging molecular detection device, which uses a curved surface holographic grating as a spectrometer and is combined with an LSPR sensor, so that the detection light passes through a trace amount of a sample solution to be tested and an LSPR sensor interface in sequence, and then undergoes spectroscopic processing by the curved surface holographic grating to form a diffraction image. There is no need to use a high-sensitivity, high-resolution spectrometer, and the process of molecular adsorption changes at the sensor unit interface can be obtained by only analyzing the distribution relationship between pixel position and intensity in the diffraction image. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of the diffraction imaging molecular detection device of the present invention, wherein 1 is a light source unit, 2 is a sensing unit, 3 is a spectroscopic unit, and 4 is a display unit.

[0037] Figure 2 It is a schematic diagram of the preparation method of the curved holographic grating of the present invention.

[0038] Figure 3 It is a schematic diagram of the diffraction image in the present invention.

[0039] Figure 4 The graph is a position-intensity curve obtained when the diffraction imaging molecular detection device of the present invention detects the adsorption changes of rabbit anti-human immunoglobulin G (IgG) and human IgG on the sensor interface. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0041] Example 1

[0042] A diffraction imaging molecular detection device (such as Figure 1As shown), it includes a light source unit 1, an LSPR sensor unit 2, a spectroscopic unit 3 and a display unit 4; the LSPR sensor unit 2 is arranged between the light source unit 1 and the spectroscopic unit 3, and the three are horizontally distributed on the same optical path; the spectroscopic unit 3 is a curved holographic grating; the light source unit 1 provides a light signal for the detection device, and after the light penetrates the solution to be tested on the LSPR sensor unit 2, it passes through the LSPR sensor unit 2 to reach the spectroscopic unit 3, and the spectroscopic unit 3 splits the light signal and projects it on the display unit 4 to form a diffraction image.

[0043] The preparation method of the LSPR sensor unit 2 comprises the following steps:

[0044] S1. The area is 3×3cm 2 The indium tin oxide conductive glass (ITO) was cleaned, and then ultrasonicated for 10 minutes using acetone and isopropanol respectively; then dried with nitrogen, and then treated with a plasma cleaner for 1 minute for later use;

[0045] S2. Spin the imprinted glue on the cleaned ITO conductive glass at a speed of 4000r / rmp and bake it on a hot plate at 120°C for 1 min;

[0046] S3. Put the glass, ITO conductive glass, imprinted silicon template, and silicone pad into the laminator in the order from bottom to top, turn on the condensation water circulation, raise the laminator temperature to 100°C, pressurize 0.3 ton, hot press for 5 minutes, and then cool down. After the temperature drops to room temperature, take out the glass, ITO conductive glass, imprinted template, and silicone pad;

[0047] S4. Separating the imprint template from the ITO conductive glass to obtain the ITO conductive glass with nanostructures;

[0048] S5. The ITO conductive glass with nanostructures is placed in a plasma cleaning machine for 30 seconds;

[0049] S6. Use acetone to erase a small piece of imprinted glue on the ITO glass, use the ITO conductive glass as the anode and the titanium mesh as the cathode, and place it in the gold plating solution to establish an electroplating system. -2 Gold deposition was performed under the following conditions:

[0050] S7. After gold deposition is completed, rinse the sample with deionized water and blow dry with nitrogen; then put it in acetone for 2 minutes, take it out, and blow dry with nitrogen.

[0051] S8. Put glass, polyethylene terephthalate (PET), ITO with metal nanostructures, and silicone pad into the laminator in the order from bottom to top, turn on the condensation water circulation, raise the laminator temperature to 100°C, apply pressure of 0.3 ton, hot stamp for 5 minutes, cool down, and take it out after the temperature drops to room temperature;

[0052] S9. Separate the PET and the ITO glass to obtain the LSPR sensing unit 2.

[0053] The method for preparing the curved holographic grating comprises the following steps (eg Figure 2 shown):

[0054] S1. Using indium tin oxide conductive glass as a carrier, copper nanogratings are formed by nanoimprinting and electroplating;

[0055] S2. Spin-coat the copper nanograting of S1 with a polyvinyl alcohol aqueous solution, and then dry it to obtain a copper nanograting / polyvinyl alcohol composite film. After spin coating, bake it on a hot plate at 80°C for 1 min.

[0056] S3. The copper nanograting / polyvinyl alcohol composite film in S2 is fixed to the convex side of the spherical lens and heated at 100°C for 1h;

[0057] S4. The spherical lens after the heat treatment in S3 is immersed in water to remove the polyvinyl alcohol to obtain a curved holographic grating;

[0058] Wherein, the weight average molecular weight of the polyvinyl alcohol in S2 is 80,000; the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution in S2 is 8%; and the thickness of the copper nanograting / polyvinyl alcohol composite film in S2 is 10 μm.

[0059] The specific preparation method of the copper nanograting is as follows:

[0060] S1. The area is 3×3cm 2 The indium tin oxide conductive glass (ITO) was cleaned, and then ultrasonicated for 10 minutes using acetone and isopropanol respectively; then dried with nitrogen, and then treated with a plasma cleaner for 1 minute for later use;

[0061] S2. Spin the imprinted glue on the cleaned ITO conductive glass at a speed of 4000r / rmp and bake it on a hot plate at 120°C for 1 min;

[0062] S3. Put the glass, ITO conductive glass, grating template, and silicone pad into the laminator in the order from bottom to top, turn on the condensation water circulation, raise the laminator temperature to 100°C, pressurize 0.3 ton, hot stamp for 5 minutes, and then cool down. After the temperature drops to room temperature, take out the glass, ITO conductive glass, stamping template, and silicone pad;

[0063] S4. Separating the imprint template from the ITO conductive glass to obtain the ITO conductive glass with nanostructures;

[0064] S5. The ITO conductive glass with nanostructures is placed in a plasma cleaning machine for 30 seconds;

[0065] S6. Use acetone to erase a small piece of embossing glue on the ITO glass, use the ITO conductive glass as the anode and the titanium mesh as the cathode, put it into the copper electroplating solution to establish the electroplating system, and set the source current density at 5 mA cm -2 Copper deposition was performed under the following conditions:

[0066] S7. After copper deposition is completed, rinse the sample with deionized water and blow dry with nitrogen; then put it in acetone for 2 minutes, take it out, and blow dry with nitrogen to obtain the copper nanograting.

[0067] Example 2

[0068] A diffraction imaging molecular detection device is the same as Example 1, except that in step S2 of the method for preparing the curved holographic grating, the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 10%.

[0069] The curved holographic grating prepared by the above preparation method has a diffraction image formed during the detection process with a clarity substantially at the same level as that of Example 1.

[0070] Example 3

[0071] A diffraction imaging molecular detection device is the same as Example 1, except that in step S2 of the curved holographic grating preparation method, the weight average molecular weight of the polyvinyl alcohol is 18,000.

[0072] When the weight average molecular weight of polyvinyl alcohol is small, it will cause partial loss when the copper nanograting is separated from the indium tin oxide conductive glass, thereby affecting the function of the curved holographic grating obtained by the above preparation method, and further making the clarity of the diffraction image formed during the detection process slightly lower than that in Example 1.

[0073] Example 4

[0074] A diffraction imaging molecular detection device is the same as Example 1, except that in step S2 of the method for preparing the curved holographic grating, the weight average molecular weight of the polyvinyl alcohol is 110,000.

[0075] The curved holographic grating prepared by the above preparation method has a diffraction image formed during the detection process with a clarity substantially at the same level as that of Example 1.

[0076] Example 5

[0077] A diffraction imaging molecular detection device is the same as Example 1, except that in step S2 of the method for preparing the curved holographic grating, the weight average molecular weight of the polyvinyl alcohol is 120,000.

[0078] When the weight-average molecular weight of polyvinyl alcohol is relatively large, using water as a solvent to dissolve and remove the polyvinyl alcohol not only takes a long time, but also results in incomplete removal of the polyvinyl alcohol, which remains between the copper nanogratings, thereby affecting the function of the curved holographic grating obtained by the above preparation method, and further causing the clarity of the diffraction image formed during the detection process to be slightly lower than that in Example 1.

[0079] Example 6

[0080] A diffraction imaging molecular detection device is the same as Example 1, except that in step S2 of the method for preparing the curved holographic grating, the thickness of the copper nanograting / polyvinyl alcohol composite film is 20 μm.

[0081] The curved holographic grating prepared by the above preparation method has a diffraction image formed during the detection process with a clarity substantially at the same level as that of Example 1.

[0082] Example 7

[0083] Taking the diffraction imaging molecular detection device in Example 1 to detect the interaction process between rabbit anti-human immunoglobulin G (IgG) and human IgG biomolecules in aqueous solution and the adsorption change process of the sensing interface as an example, the main process is as follows:

[0084] Step 1) First, PBS solution was dripped onto the surface of the LSPR sensor unit 2, and then 11-mercaptoundecanoic acid (MUA) solution was dripped and incubated for 60 min to modify the surface of the LSPR sensor unit 2; then, N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) solution was dripped for activation for 30 min, and then washed with PBS buffer solution; finally, rabbit anti-human immunoglobulin G was dripped onto the surface of the LSPR sensor unit 2 and allowed to stand for 120 min.

[0085] Step 2) PBS buffer solutions of human IgG at concentrations of 0, 0.2 ng / mL, 0.4 ng / mL, 0.8 ng / mL, 1 ng / mL, 10 ng / mL, 100 ng / mL, and 1000 ng / mL are sequentially dripped onto the surface of the LSPR sensor unit 2, and each incubation is 30 minutes to allow rabbit anti-human immunoglobulin G to fully and specifically bind to human IgG. Turn on the light source, and use a monochrome camera to record the diffraction image after the specific binding and adsorption of rabbit anti-human immunoglobulin G and human IgG. No instrument movement occurs during the entire detection process; wherein, before dripping a higher concentration of human IgG solution each time, the unbound human IgG is rinsed and removed using a PBS solution.

[0086] Step 3) Analyze the diffraction image and draw a position-intensity relationship curve (such as Figure 4 shown), by Figure 4 It can be seen that at different human IgG concentrations, the position of the maximum diffraction image intensity moves. When the concentration of human IgG is 0.2ng / mL, 0.4ng / mL, 0.8ng / mL, 1ng / mL, 10ng / mL, 100ng / mL, and 1000ng / mL, the position of the maximum diffraction image intensity shifts by 2, 4, 6, 10, 13, 16, and 24 pixels, respectively, indicating that the refractive index of the sample solution to be tested has changed, and further indicating that the process of molecular adsorption changes at the sensor unit interface can be detected only by the diffraction imaging molecular detection device of the present invention.

[0087] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A diffraction imaging molecular detection device, characterized in that: The device comprises a light source unit (1), an LSPR sensor unit (2), a spectroscopic unit (3) and a display unit (4); the LSPR sensor unit (2) is arranged between the light source unit (1) and the spectroscopic unit (3), and the three are arranged in parallel on the same optical path; the spectroscopic unit (3) is a curved holographic grating; the light source unit (1) provides a light signal for the detection device, and the light penetrates the sample solution to be tested on the LSPR sensor unit (2), and then passes through the LSPR sensor unit (2) to reach the spectroscopic unit (3), and the spectroscopic unit (3) splits the light signal and projects it onto the display unit (4) to form a diffraction image; Wherein, the curved holographic grating is obtained by the following preparation method: S1. Using indium tin oxide conductive glass as a carrier, first nanoimprinting and then electroplating to form a copper nanograting; S2. The polyvinyl alcohol aqueous solution is evenly coated on the copper nanograting in S1, and then dried to form a copper nanograting / polyvinyl alcohol composite film; S3. The copper nanograting / polyvinyl alcohol composite film in S2 is fixed to the convex side of the spherical lens and heated; S4. The curved holographic grating can be obtained by removing the polyvinyl alcohol from the copper nanograting / polyvinyl alcohol composite film; The weight average molecular weight of the polyvinyl alcohol in S2 is 80,000 to 110,000; The period of the copper nano-grating is 606 nm, and the focal length of the spherical lens is 14 mm.

2. The diffraction imaging molecular detection device according to claim 1, characterized in that: The method for removing polyvinyl alcohol in the copper nanograting / polyvinyl alcohol composite film in S4 is to immerse the spherical lens after the heat treatment in S3 in water to dissolve and remove the polyvinyl alcohol.

3. The diffraction imaging molecular detection device according to claim 1, characterized in that: The thickness of the copper nanograting / polyvinyl alcohol composite film in S2 is 10-20 μm.

4. The diffraction imaging molecular detection device according to claim 1, characterized in that: The light source unit (1) is a monochromatic light source.

5. A molecular detection device based on a monochrome camera, characterized in that: The molecular detection device based on a monochrome camera is composed of the diffraction imaging molecular detection device according to claim 1 and a monochrome camera, and the monochrome camera is used to record the diffraction image detected by the diffraction imaging molecular detection device.

6. An application of the diffraction imaging molecular detection device according to claim 1 in detecting the change process of environmental refractive index, biological molecules in solution and their adsorption change process at the sensor interface.

7. The application of the diffraction imaging molecular detection device as claimed in claim 6 in detecting the change process of environmental refractive index, biological molecules in solution and their adsorption change process at the sensor interface, characterized in that: The following steps are involved: S1. adding sample solutions of different concentrations to be tested to the LSPR sensor unit (2) of the diffraction imaging molecular detection device respectively, and obtaining different diffraction images projected on the display unit (4); S2. The position-intensity curve of the diffraction image is obtained by averaging the intensity of each row of pixels at different positions of different diffraction images in S1; The intensity average value of each row of pixels is obtained by summing the intensity values ​​of each pixel in a row of pixels at different positions and dividing the sum by the number of pixels in the row.

Images