Molecular interaction instrument based on all-dielectric optical metasurface and implementation method

Abstract

The invention discloses a molecular interaction instrument based on an all-dielectric optical metasurface and an implementation method, and belongs to the technical field of high-sensitivity molecular interaction detection.The molecular interaction instrument comprises a sensor based on an all-dielectric optical metasurface structure and an angle measurement system based on continuous wave laser; wherein geometric perturbation exists in the metasurface structure based on the all-dielectric optical metasurface structure sensor, so that the metasurface structure generates a period doubling effect; the metasurface structure sensor is subjected to functionalization treatment, so that affinity layer molecules coupled with target molecules to be detected are fixed on the surface of the metasurface structure sensor, and the metasurface structure sensor based on all-dielectric optics after the functionalization treatment is put into an angle measurement system based on continuous wave laser to detect the target molecules. According to the molecular interaction instrument disclosed by the invention, an expensive spectrograph is not needed, and low-cost, high-sensitivity and multifunctional molecular interaction detection is realized by utilizing a high-Q-factor optical resonance mode and an angle scanning technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-sensitivity molecular interaction detection, and specifically relates to a molecular interaction instrument based on an all-dielectric optical metasurface and an implementation method thereof. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, surface plasmon resonance (SPR) sensor technology has been widely used in many fields due to its high sensitivity and real-time detection capabilities. However, SPR sensors have the following shortcomings: (1) Intrinsic loss of metal materials: The quality factor (i.e., Q factor) of the SPR sensor is low, resulting in insufficient detection sensitivity for low-concentration molecules.

[0004] (2) Limited scope of surface functionalization: The surface of gold SPR sensors can usually only be modified by thiol groups, which limits their application in the detection of various biomolecules.

[0005] (3) High detection cost: SPR sensors based on resonant wavelength shift require the use of expensive spectrometers for characterization, which increases the detection cost and limits its application in large-scale detection. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a molecular interaction instrument based on an all-dielectric optical metasurface and an implementation method thereof, which does not require an expensive spectrometer and utilizes a high-quality factor (i.e., high Q factor) optical resonance mode and angle scanning technology to achieve low-cost, high-sensitivity molecular interaction detection.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions: Firstly, the technical solution of the present invention provides a molecular interaction instrument based on an all-dielectric optical metasurface, including: an angle measurement system based on an all-dielectric optical metasurface structure sensor and a continuous wave laser; Among them, there are geometric perturbations in the metasurface structure of the all-dielectric optical metasurface structure sensor, which causes a period doubling effect in the metasurface structure; the metasurface structure sensor is functionalized to fix affinity layer molecules coupled with target molecules to be detected on its surface, and the functionalized all-dielectric optical metasurface structure sensor is placed in an angle measurement system based on a continuous wave laser to detect the target molecules.

[0008] In at least one embodiment, the sensor based on the all-dielectric optical metasurface structure uses all-dielectric materials to construct the optical metasurface structure, supporting a quasi-guided mode resonance mode with a high quality factor; a double grating metasurface is constructed on a sample with a low refractive index substrate at the bottom and a high refractive index material at the top, and a periodic structure is formed by two asymmetric grating strips.

[0009] In at least one embodiment, the two asymmetric grating strips are specifically two grating strips with the same height but different widths; the difference between the widths of the two grating strips in the single periodic structure is the added geometric perturbation.

[0010] In at least one embodiment, the center distance between two asymmetric grating strips in a single periodic structure is half the length of a single period.

[0011] In at least one embodiment, the periodic structure is a one-dimensional periodic grating array, or a two-dimensional periodic columnar array, or a two-dimensional periodic air void array in a high refractive index dielectric film.

[0012] In at least one embodiment, the surface of the sensor based on the all-dielectric optical metasurface structure is functionalized to produce a variety of functional groups, thereby fixing different probe molecules to achieve the detection of a variety of biological molecules.

[0013] In at least one embodiment, the functional group includes one or more of hydroxyl, amino, and carboxyl groups.

[0014] In at least one embodiment, the continuous wave laser-based angle measurement system is composed of a continuous wave laser with a single wavelength output, a polarizer, a rotatable sample stage with a liquid chamber, a focusing lens, and a power meter in sequence; After the functionalization process of the all-medium optical metasurface structure sensor is completed, it is placed on a rotatable sample stage with a liquid chamber, and a liquid containing target molecules to be detected is introduced into the liquid chamber. Based on the angle scanning technology, the effect of the molecular interaction is detected.

[0015] Secondly, the technical solution of the present invention also provides a method for realizing a molecular interaction instrument based on an all-medium optical metasurface, including: Functionalize the sensor based on the all-medium optical metasurface structure to fix the probe molecules on its surface; The functionalized all-medium optical metasurface structure sensor is placed between the sample stage and the liquid chamber, and a buffer solution is introduced into the liquid chamber; The output wavelength of a continuous wave laser with single wavelength output is fixed at a set value; Rotate the sample stage to adjust the incident angle, record the power value of the power meter, and draw the angle transmission spectrum; A liquid containing the target molecule to be detected is introduced into the liquid chamber, the sample stage is rotated to adjust the incident angle, the power value of the power meter is recorded, the angle transmission spectrum is drawn, and the change of the power value of the power meter is recorded; Different concentrations of target molecules will cause different degrees of displacement in the angle transmission spectrum, and the concentration of the target molecules can be quantitatively detected by the size of the displacement.

[0016] Again, the technical solution of the present invention also provides another method for realizing a molecular interaction instrument based on an all-dielectric optical metasurface, comprising: Perform functional processing on the sensor based on the all-medium optical metasurface structure to fix the probe molecules on its surface; The functionalized all-medium optical metasurface structure sensor is placed between the sample stage and the liquid chamber, and a buffer solution is introduced into the liquid chamber; The output wavelength of a continuous wave laser with single wavelength output is fixed at a set value; Turn the sample stage to adjust the incident angle, find the incident angle when the power value of the power meter is the lowest, and fix the sample stage; Pass liquid containing the target molecule to be detected and observe the change in the power value of the power meter; As the concentration of the target molecule increases, the power value of the power meter will gradually increase, and the concentration of the target molecule can be quantitatively detected by the change in the power value.

[0017] The beneficial effects of the technical solution of the present invention are as follows: 1) High sensitivity: The zero absorption loss and controllable radiation loss in the all-dielectric optical metasurface structure can significantly improve the resonant Q factor, so that it can still be easily observed when the spectrum moves in a very small range, making the detection of low-concentration molecules more sensitive.

[0018] 2) Low system cost: Using continuous wave lasers and power meters instead of expensive spectrometers greatly reduces equipment costs.

[0019] 3) Multifunctionality: Through different surface functionalization treatments, a variety of biological molecules or drug molecules can be detected.

[0020] 4) Reusability: Metasurface sensors are highly stable and can be reused many times, further reducing detection costs.

[0021] 5) Real-time detection: It can monitor the occurrence of molecular interactions in real time and is suitable for dynamic monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 It is a schematic diagram of a single periodic structure of a one-dimensional grating metasurface constructed based on QGM in the present invention; Figure 2 It is a dispersion relation diagram of the one-dimensional grating metasurface without perturbation δ (δ=0) and with perturbation δ (δ=9nm) of the present invention; Figure 3 is a schematic diagram of the energy band folding process of the present invention; Figure 4 It is the transmission spectrum supported by the one-dimensional grating metasurface sensor of the present invention in different refractive index environments; Figure 5 It is the angular transmission spectrum supported by the one-dimensional grating metasurface sensor of the present invention at different incident wavelengths; Figure 6 The present invention fixes the incident wavelength at 1570nm, places the one-dimensional grating metasurface sensor in different refractive index environments, and measures the angular transmission spectrum of the metasurface sensor; Figure 7 is a schematic diagram of an angle measurement system of the present invention; Figure 8 This is a result diagram obtained when the angle measurement system of the present invention measures different refractive index environments; Fig. 9 This is a result diagram obtained when the angle measurement system of the present invention measures different refractive index environments at a fixed angle.

[0024] In the attached figure, 1 is a continuous wave laser with single wavelength output; 2 is a polarizer; 3 is a rotatable sample stage; 4 is a liquid chamber; 5 is a focusing lens; 6 is an optical fiber; and 7 is a power meter.

[0025] In order to show the positions of various parts, the distances or sizes between them are exaggerated and the schematic diagram is for reference only. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0027] As introduced in the background technology, the purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a molecular interaction instrument and implementation method based on an all-dielectric optical metasurface, which utilizes high-Q factor optical resonance mode and angle scanning technology to achieve low-cost and high-sensitivity molecular interaction detection.

[0028] Example 1 In a typical embodiment of the present invention, this embodiment discloses a molecular interaction instrument based on an all-dielectric optical metasurface, comprising: an all-dielectric optical metasurface structure sensor and an angle measurement system based on a continuous wave laser; wherein, there are geometric perturbations in the metasurface structure of the all-dielectric optical metasurface structure sensor, so that the metasurface structure undergoes a period doubling effect; the metasurface structure sensor is functionalized to fix affinity layer molecules coupled to the target molecules to be detected on its surface, and the functionalized all-dielectric optical metasurface structure sensor is placed in the angle measurement system based on a continuous wave laser to detect the target molecules.

[0029] The detailed description is given below.

[0030] The sensor based on the all-dielectric optical metasurface structure uses all-dielectric materials to construct an optical metasurface structure, which supports a quasi-guided mode resonance mode with a high quality factor; a double-grating metasurface is constructed on a sample with a low-refractive index substrate on the lower layer and a high-refractive index material on the upper layer, and a periodic structure is formed by two asymmetric grating strips; there are geometric perturbations in the metasurface structure, which causes a period doubling effect in the metasurface structure.

[0031] The all-dielectric optical metasurface structure mentioned in this embodiment adopts an all-dielectric optical structure and supports a quasi-guided mode (QGM) resonant mode with a high quality factor. The QGM mode introduces geometric perturbations in the sub-wavelength periodic structure so that the period is doubled to the wavelength level. In this way, the guided wave mode energy band originally supported in the sub-wavelength structure will appear above the light due to the folding of the Brillouin zone of the periodic structure, thereby forming a leakage mode such as QGM.

[0032] In this embodiment, the all-dielectric optical metasurface structure is introduced from the aspects of material system, structural characteristics and optical characteristics: (1) Material system: The all-dielectric optical structure material system supporting the QGM mode includes but is not limited to high refractive index (refractive index greater than 2.0) dielectric materials on sapphire or silicon dioxide substrates, including silicon, silicon nitride and Group III-V semiconductors.

[0033] Therefore, in this embodiment, the upper layer of the all-dielectric metasurface sensor is a high-refractive index material, including but not limited to silicon material; the lower layer is a low-refractive index substrate, including but not limited to aluminum oxide.

[0034] (2) Structural characteristics: The introduction of geometric perturbations causes the period of the entire structure to jump, thereby achieving the contraction of the first Brillouin zone and the folding of the energy band.

[0035] In this embodiment, the periodic structure can be a one-dimensional periodic grating array, or a two-dimensional periodic columnar array, or a two-dimensional periodic air hole array in a high refractive index dielectric film, etc. The introduction of period doubling perturbations can be achieved by changing the width of specific grating strips, columns or air holes, or the distance between these structures, etc. The key is that when the period doubling perturbation does not exist, the period of the entire structure is halved, thereby supporting a tightly bound waveguide mode that cannot be excited by a free-space beam. When the period doubling perturbation exists, the waveguide mode is converted into a quasi-guided mode that can be excited by a free-space beam, and the quality factor of the quasi-guided mode can be controlled by the size of the perturbation.

[0036] (3) Optical properties: The quality factor of the QGM mode can be controlled by the amplitude of the geometric perturbation, thereby achieving high quality factor characteristics; in addition, the QGM still maintains the steep dispersion band curve in the original subwavelength structure, so the size of the resonant wavelength can be tuned by changing the incident angle.

[0037] In this embodiment, since the quasi-guided mode still maintains the guided mode dispersion curve before the introduction of the period doubling perturbation, but the dispersion curve is folded above the light dispersion curve, for a certain processed metasurface structure, the resonant wavelength can be tuned by the position on the dispersion curve or the incident angle of the incident free-space light beam.

[0038] In this embodiment, a double grating metasurface is constructed on a sample with a sapphire substrate and a silicon-based material as the upper layer. Its basic unit (i.e., a single periodic structure) is composed of two asymmetric grating strips, such as Figure 1 As shown, the center distance between the two grating strips is p / 2, p is the period of the basic unit in the X direction, and the heights of the two grating strips are the same, but their widths are different. The difference in the widths of the two grating strips in a single periodic structure is defined as δ.

[0039] When the widths of the two grating strips are equal (i.e., δ=0), the structure suddenly changes to a single grating structure, and the period is reduced to 0.5p. At this time, although the metasurface is still a periodic structure, the period is much smaller than the applied laser wavelength, so it still supports a tightly bound guided wave mode, whose energy band is located below the light, and this mode cannot couple with the free space. Figure 2 The dispersion relation diagram of the one-dimensional grating metasurface without perturbation δ (δ = 0) and with perturbation δ (δ = 9 nm) is shown. In the figure, X is the first Brillouin zone k when the basic unit period is p / 2. x The boundary point in the direction, X' is the first Brillouin zone k when the basic unit period is p x The boundary point in the direction, Г is the center of the Brillouin zone, corresponding to the zero wave vector point. Figure 2 The solid black line in the middle shows that the dispersion relation of the single grating metasurface is in a bound state and cannot be excited from the far field.

[0040] When a periodic perturbation (i.e., δ≠0) is introduced on the basis of the traditional single-grating metasurface, the period is doubled to p, which causes the guided mode originally in the bound state to fold into the continuous domain, forming a quasi-guided mode. Figure 2 As shown by the dashed line in the middle, when the width of each second grating is increased (δ=9nm), the period of the basic unit is doubled in the X direction, which leads to the energy band in k x The QGM folded in the continuous domain can still maintain a high Q factor. Figure 3 This is a schematic diagram of the Brillouin zone band folding, which explains the specific process of band folding: Since the wave vector range of the first Brillouin zone is inversely proportional to the period, when the period doubles, the wave vector range of the Brillouin zone will be halved. Therefore, the energy band originally distributed in the high wave vector region will be folded to the low wave vector region.

[0041] The structural diagram of a single unit of the double grating metasurface sensor constructed based on the QGM mode in this embodiment is shown in FIG. Figure 1 As shown in the figure, the specific parameters are: the width of the grating is w = 120nm, the height is h = 300nm, the period of the basic unit in the x direction is p = 600nm, and the period perturbation is δ = 9nm. These structural parameters can be changed as needed to scale the size of the structure so that the grating metasurface sensor can match the wavelength required for the research.

[0042] The dual-grating metasurface sensor designed in this embodiment can support resonance with a high quality factor in a specific wavelength range. The dispersion curve of the dual-grating metasurface sensor is calculated based on the finite element method simulation calculation, and the results are as follows: Figure 2 As shown by the black dotted line in . It can be seen that this dispersion curve is very steep, so the double grating metasurface sensor can support resonance in a larger wavelength range, which brings greater flexibility to subsequent measurements. Figure 4 This is the result of numerical simulation of the transmission spectrum of the dual grating metasurface sensor in different refractive index environments. It can be seen that when the refractive index of the structure surface increases, its resonance position will move to a larger wavelength, thereby satisfying the resonance condition again. Furthermore, the angular transmission spectrum of the dual grating metasurface sensor was simulated and calculated, and the results are shown in Figure 2. Figure 5 As shown in the figure, it can be seen that the dual-grating metasurface sensor can support resonance at different wavelengths under different incident angles. This provides more flexibility for the selection of laser wavelength in subsequent angle measurement systems.

[0043] Figure 6This is the result of numerical simulation of the angular transmission spectrum of the dual-grating metasurface sensor in different refractive index environments. It can be seen that when the refractive index of the structure surface increases, its resonance position will move to a smaller incident angle, thereby satisfying the resonance condition again. In this way, the concentration of the molecule to be detected can be quantitatively characterized by the size of the shift in the resonance angle.

[0044] Assume that the high refractive index material used to construct the dual-grating metasurface sensor is silicon. This material can produce a variety of functional groups such as hydroxyl, amino, and carboxyl during surface modification. A variety of different probe molecules can be fixed on its surface, thereby increasing the types of molecules that can be detected and enabling the detection of a variety of biological molecules. After further functionalization of the above-mentioned dual-grating metasurface sensor, specific probe molecules are fixed on the surface of the dual-grating metasurface sensor to measure the target molecules. Target molecules of different concentrations are coupled with probe molecules, which will cause different refractive index changes in the surface environment of the dual-grating metasurface sensor. The higher the concentration, the greater the refractive index change, which will cause the resonance position to move in the angular transmission spectrum. Figure 6 As shown, different refractive index environments cause the angular transmission spectrum to undergo different degrees of blue shift.

[0045] In this embodiment, the functionalization treatment mainly involves chemical treatment of the surface of the metasurface sensor, including hydroxylation of the metasurface sensor, followed by activation with 3-aminopropyltriethoxysilane, and fixation of biotin probe molecules, thereby generating a variety of functional groups such as hydroxyl, amino, and carboxyl groups on the surface of the metasurface sensor, thereby fixing different probe molecules, realizing the detection of a variety of biological molecules, and expanding the scope of sensor surface functionalization.

[0046] Due to the high stability of all-dielectric materials, metasurface sensors can maintain their physical properties after repeated use. After cleaning the surface with concentrated sulfuric acid or oxygen plasma, the surface can be re-modified for reuse. Even the same metasurface sample can be used to detect different target molecules, greatly reducing the detection cost.

[0047] like Figure 7 As shown, the angle measurement system based on continuous wave laser is composed of a continuous wave laser 1 with single wavelength output, a polarizer 2, a rotatable sample stage 3 with a liquid chamber 4, a focusing lens 5 and a receiving end-power meter 7 connected by an optical fiber 6 in sequence; wherein, after the functionalization treatment of the all-medium optical metasurface structure sensor is completed, it is placed on the rotatable sample stage 3 with a liquid chamber 4, and a liquid containing the target molecules to be detected is passed into the liquid chamber 4, and the effect of the molecular interaction is detected based on the angle scanning technology.

[0048] Specifically, the continuous wave laser 1 with a single wavelength output can adopt a continuous wave laser with a single wavelength output, such as a distributed feedback laser mode used in optical communication; the receiving end of the system can adopt a power meter 7 to detect the transmittance change, such as a low-cost power meter in an optical network; the rotatable sample stage 3 can adopt an electric rotating platform or a manual rotating platform to adjust the incident angle; the polarizer 2 is used to control the polarization state of the incident light; the rotatable sample stage 3 with a liquid chamber 4 is used to load the metasurface sensor and the solution to be tested; the focusing lens 5 is used to converge the incident light.

[0049] During the detection process, the incident angle is adjusted by an electric rotating platform to put the metasurface structure in a resonant state, at which the transmittance is the lowest. When molecular interactions occur, the resulting slight changes in the refractive index will cause the structure to deviate from the resonant state, resulting in changes in transmittance. By measuring changes in transmittance, the occurrence of molecular interactions can be monitored in real time. Moreover, the use of economical continuous wave lasers and power meters instead of expensive spectrometers greatly reduces equipment costs, has better universality, and can be used in large-scale detection.

[0050] Example 2 In a typical implementation of the present invention, this embodiment discloses a method for realizing a molecular interaction instrument based on an all-dielectric optical metasurface, which includes two characterization methods: an angle transmission spectrum measurement method and a fixed angle measurement method. The following introduces them one by one by taking the fixed output wavelength of the laser as 1570nm as an example.

[0051] Method 1: Angle transmission spectrum measurement method.

[0052] S1. Metasurface sensor preparation: Using a high refractive index medium on a low refractive index substrate (such as silicon on sapphire, or silicon on quartz glass, etc.), a periodic nanostructure that conforms to the working principle of QGM is manufactured based on micromachining methods.

[0053] S2. Surface functionalization: The fabricated silicon-based double grating metasurface sensor is functionalized to fix the probe molecules on its surface. The steps are hydroxylation, activation with (3-aminopropyl) triethoxysilane (APTES), and fixation of biotin probe molecules.

[0054] S3. Loading samples: Place the functionalized metasurface sensor on a rotatable sample stage with a liquid chamber, and pass a buffer solution into the liquid chamber.

[0055] S4. Laser settings: Set the output wavelength of the single-wavelength continuous wave laser to 1570nm. The value of this fixed wavelength depends on whether the QGM energy band extends upward or downward as the wave vector increases. This wavelength needs to be shorter or longer than the resonant wavelength at vertical incidence, so that the QGM mode is excited when the incident angle is positive.

[0056] S5. Angle scanning: Turn the sample stage, adjust the incident angle through the rotating sample stage platform, record the power value of the power meter at the same time, and draw the angle transmission spectrum.

[0057] S6. Target molecule detection: Pass a solution containing target molecules (such as streptavidin) into the liquid chamber, repeat S5, and record the power value change of the power meter. Different concentrations of target molecules will cause different degrees of displacement of the angle transmission spectrum, and the concentration of the target molecule can be quantitatively detected by the displacement size.

[0058] Figure 8 The simulation diagram of the results of measuring target molecules of different concentrations using the method is shown. When the target substance is contained in the detection liquid, the probe molecules on the double grating metasurface sensor will couple with the target molecules, thereby increasing the refractive index of the sensor surface, causing the angle transmission spectrum of the double grating metasurface sensor to shift. The greater the concentration, the greater the increase in the refractive index of the sensor surface, and the greater the shift in the angle transmission spectrum. The concentration of the target molecule can be quantitatively determined by the shift in the resonance angle.

[0059] Method 2: Fixed angle measurement method.

[0060] S1. Metasurface sensor preparation: Using a high refractive index medium on a low refractive index substrate (such as silicon on sapphire, or silicon on quartz glass, etc.), a periodic nanostructure that conforms to the working principle of QGM is manufactured based on micromachining methods.

[0061] S2. Surface functionalization: The fabricated silicon-based double grating metasurface sensor is functionalized to fix the probe molecules on its surface. The steps are hydroxylation, activation with (3-aminopropyl) triethoxysilane (APTES), and fixation of biotin probe molecules.

[0062] S3. Loading samples: Place the functionalized metasurface sensor on a rotatable sample stage with a liquid chamber, and pass a buffer solution into the liquid chamber.

[0063] S4. Laser settings: Set the output wavelength of the single-wavelength continuous wave laser to 1570nm. The value of this fixed wavelength depends on whether the QGM energy band extends upward or downward as the wave vector increases. This wavelength needs to be shorter or longer than the resonant wavelength at vertical incidence, so that the QGM mode is excited when the incident angle is positive.

[0064] S5. Angle adjustment: Turn the sample stage, adjust the incident angle by rotating the sample stage platform, find the rotation angle corresponding to the minimum reading of the power meter, and fix the sample stage at this angle.

[0065] S6. Target molecule detection: a solution containing the target molecule is introduced into the liquid chamber, and the change in the power meter reading is observed; target molecules of different concentrations are detected, and S5 is repeated.

[0066] As the concentration of the target molecule increases, the power meter reading will gradually increase, and the concentration of the target molecule can be quantitatively detected by the change in the reading.

[0067] Fig. 9 The results of using method 2 to detect target molecules of different concentrations are shown. When the liquid to be detected contains target molecules, the probe molecules on the sensor will couple with them, causing the refractive index of the sensor surface to increase, which in turn causes the resonance position of the sensor to move, and the power meter reading will increase. The greater the concentration, the greater the deviation of the resonance position from 1570nm, and the power meter reading will further increase. At the same time, the real-time performance of method 2 is higher than that of method 1.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A molecular interaction instrument based on an all-dielectric optical metasurface, characterized in that: include: Angle measurement system based on all-dielectric optical metasurface structure sensor and continuous wave laser; There is a geometric perturbation in the metasurface structure of the all-medium optical metasurface structure sensor, which causes a period doubling effect to occur in the metasurface structure. The metasurface structure sensor is functionalized so that affinity layer molecules coupled with target molecules to be detected are fixed on its surface. The functionalized all-medium optical metasurface structure sensor is placed in an angle measurement system based on continuous wave laser to detect the target molecules.

2. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 1, characterized in that: The all-dielectric optical metasurface structure sensor uses all-dielectric materials to construct an optical metasurface structure, supporting a quasi-guided mode resonance mode with a high quality factor; a double grating metasurface is constructed on a sample with a low refractive index substrate at the bottom and a high refractive index material at the top, and a periodic structure is formed by two asymmetric grating strips.

3. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 2, characterized in that: The periodic structure is a one-dimensional periodic grating array, or a two-dimensional periodic columnar array, or a two-dimensional periodic air void array in a high refractive index medium film.

4. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 2, characterized in that: Specifically, the two asymmetric grating strips have the same height but different widths; the difference in width between the two grating strips in a single periodic structure is the added geometric perturbation.

5. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 4, characterized in that: The center distance between two asymmetric grating strips in a single periodic structure is half the length of a single period.

6. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 1, characterized in that: The surface of the sensor based on the all-medium optical metasurface structure is functionalized to produce a variety of functional groups, thereby fixing different probe molecules and realizing the detection of a variety of biological molecules.

7. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 6, characterized in that: The functional groups include one or more of hydroxyl, amino and carboxyl groups.

8. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 1, characterized in that: The angle measurement system based on continuous wave laser is composed of a continuous wave laser with single wavelength output, a polarizer, a rotatable sample stage with a liquid chamber, a focusing lens and a power meter in sequence; After the functionalization process of the all-medium optical metasurface structure sensor is completed, it is placed on a rotatable sample stage with a liquid chamber, and a liquid containing target molecules to be detected is introduced into the liquid chamber. Based on the angle scanning technology, the effect of the molecular interaction is detected.

9. A method for realizing a molecular interaction instrument based on an all-medium optical metasurface, characterized in that: include: Functionalize the sensor based on the all-medium optical metasurface structure to fix the probe molecules on its surface; The functionalized all-medium optical metasurface structure sensor is placed between the sample stage and the liquid chamber, and a buffer solution is introduced into the liquid chamber; The output wavelength of a continuous wave laser with single wavelength output is fixed at a set value; Rotate the sample stage to adjust the incident angle, record the power value of the power meter, and draw the angle transmission spectrum; A liquid containing the target molecule to be detected is introduced into the liquid chamber, the sample stage is rotated to adjust the incident angle, the power value of the power meter is recorded, the angle transmission spectrum is drawn, and the change of the power value of the power meter is recorded; Different concentrations of target molecules will cause different degrees of displacement in the angle transmission spectrum, and the concentration of the target molecules can be quantitatively detected by the size of the displacement.

10. A method for realizing a molecular interaction instrument based on an all-medium optical metasurface, characterized in that: include: Perform functional processing on the sensor based on the all-medium optical metasurface structure to fix the probe molecules on its surface; The functionalized all-medium optical metasurface structure sensor is placed between the sample stage and the liquid chamber, and a buffer solution is introduced into the liquid chamber; The output wavelength of a continuous wave laser with single wavelength output is fixed at a set value; Turn the sample stage to adjust the incident angle, find the incident angle when the power value of the power meter is the lowest, and fix the sample stage; Pass liquid containing the target molecule to be detected and observe the change in the power value of the power meter; As the concentration of the target molecule increases, the power value of the power meter will gradually increase, and the concentration of the target molecule can be quantitatively detected by the change in the power value.

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