Molecular Interaction Instrument Based on All-Dielectric Optical Metasurface and Implementation Method

Abstract

The present invention discloses a molecular interaction instrument based on an all-dielectric optical metasurface and a realization method, belonging to the technical field of high-sensitivity molecular interaction detection, including: an all-dielectric optical metasurface structure sensor and an angle measurement system based on a continuous-wave laser; wherein, there is a geometric perturbation in the metasurface structure of the all-dielectric optical metasurface structure sensor, which causes the metasurface structure to have a period-doubling effect; the metasurface structure sensor is functionalized so that an affinity layer molecule coupled with the target molecule to be detected is fixed 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 molecule. The molecular interaction instrument of the present invention does not require an expensive spectrometer, and uses a high-Q-factor optical resonance mode and angle scanning technology to achieve low-cost, high-sensitivity, and multi-functional molecular interaction detection.

Description

Technical Field

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

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

[0003] In recent years, due to its high sensitivity and real - time detection ability, the surface plasmon resonance (SPR) sensor technology has been widely applied in multiple fields. However, the SPR sensor has the following deficiencies:

[0004] (1) The inherent loss of metal materials: The quality factor (i.e., Q - factor) of the SPR sensor is relatively low, resulting in insufficient detection sensitivity for low - concentration molecules.

[0005] (2) Limited surface functionalization range: The surface of the gold SPR sensor can usually only be modified through thiol groups, which limits its application in the detection of various biomolecules.

[0006] (3) High detection cost: The SPR sensor based on the shift of the resonant wavelength requires the use of expensive spectrometers for characterization, increasing the detection cost and limiting its application in large - scale detection. Summary of the Invention

[0007] The purpose of the present invention is to overcome the above - mentioned deficiencies existing in the prior art, and provide a molecular interaction instrument based on an all - dielectric optical metasurface and a realization method thereof. Without the need for expensive spectrometers, it uses high - quality - factor (i.e., high Q - factor) optical resonance modes and angle - scanning technology to achieve low - cost and high - sensitivity molecular interaction detection.

[0008] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0009] First of all, the technical solution of the present invention provides a molecular interaction instrument based on an all - dielectric optical metasurface, including: an all - dielectric optical metasurface - based structure sensor and a continuous - wave laser - based angle measurement system;

[0010] Among them, there is a geometric perturbation in the metasurface structure of the all - dielectric optical metasurface - based structure sensor, which causes the metasurface structure to have a period - doubling effect; the metasurface structure sensor is functionalized so that an affinity - layer molecule that is coupled to the target molecule to be detected is fixed on its surface, and the functionalized all - dielectric optical metasurface - based structure sensor is placed in the continuous - wave laser - based angle measurement system to detect the target molecule.

[0011] In at least one embodiment, 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 on the lower layer and a high-refractive-index material on the upper layer, and a periodic structure is composed of two asymmetric grating bars.

[0012] In at least one embodiment, the two asymmetric grating bars are specifically such that the two grating bars have the same height but different widths; the difference in the widths of the two grating bars in a single periodic structure is the added geometric perturbation.

[0013] In at least one embodiment, the center distance between the two asymmetric grating bars in a single periodic structure is half of the single-period length.

[0014] In at least one embodiment, the periodic structure is a one-dimensional periodic grating array, or a two-dimensional periodic column array, or a two-dimensional periodic air hole array in a high-refractive-index dielectric thin film.

[0015] In at least one embodiment, after the surface of the all-dielectric optical metasurface structure sensor is functionalized, various functional groups are generated, thereby fixing different probe molecules and realizing the detection of multiple biomolecules.

[0016] In at least one embodiment, the functional groups include one or several of hydroxyl, amino, and carboxyl.

[0017] In at least one embodiment, the angle measurement system based on a continuous-wave laser is successively 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;

[0018] After the functionalization of the all-dielectric optical metasurface structure sensor is completed, it is placed on a rotatable sample stage with a liquid chamber, and a liquid containing the target molecule to be detected is introduced into the liquid chamber, and the effect of molecular interaction is detected based on the angle scanning technique.

[0019] Secondly, the technical solution of the present invention also provides a method for realizing a molecular interaction instrument based on an all-dielectric optical metasurface, including:

[0020] Functionalize the all-dielectric optical metasurface structure sensor to complete the fixation of probe molecules on its surface;

[0021] Place the functionalized all-dielectric optical metasurface structure sensor between the sample stage and the liquid chamber, and introduce a buffer solution into the liquid chamber;

[0022] Fix the output wavelength of the continuous-wave laser with single-wavelength output at the set value;

[0023] Rotate the sample stage to adjust the incident angle, record the power value of the power meter, and plot the angle transmission spectrum;

[0024] Introduce the liquid containing the target molecule to be detected into the liquid chamber, rotate the sample stage to adjust the incident angle, record the power value of the power meter, plot the angle transmission spectrum, and record the change in the power value of the power meter;

[0025] Target molecules with different concentrations will cause different degrees of displacement of the angle transmission spectrum, and the concentration of the target molecule is quantitatively detected by the magnitude of the displacement.

[0026] Again, the technical solution of the present invention also provides another implementation method of a molecular interaction instrument based on an all-dielectric optical metasurface, including:

[0027] Perform functional processing on the all-dielectric optical metasurface structure sensor to fix the probe molecules on its surface;

[0028] Place the functionalized all-dielectric optical metasurface structure sensor between the sample stage and the liquid chamber, and introduce buffer solution into the liquid chamber;

[0029] Fix the output wavelength of the continuous-wave laser with single-wavelength output at the set value;

[0030] Rotate 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;

[0031] Introduce the liquid containing the target molecule to be detected, and observe the change in the power value of the power meter;

[0032] 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 is quantitatively detected by the change in the power value.

[0033] The beneficial effects of the above technical solution of the present invention are as follows:

[0034] 1) High sensitivity: The zero absorption loss and controllable radiation loss in the all-dielectric optical metasurface structure can significantly improve the resonance Q factor, so that it can still be easily observed even when the spectral shift is very small, making the detection of low-concentration molecules more sensitive.

[0035] 2) Low system cost: Use a continuous-wave laser and a power meter instead of an expensive spectrometer, which greatly reduces the equipment cost.

[0036] 3) Versatility: By different surface functionalization treatments, various biomolecules or drug molecules can be detected.

[0037] 4) Reusability: The metasurface sensor has high stability and can be reused multiple times, further reducing the detection cost.

[0038] 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

[0039] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0040] Figure 1 is a schematic diagram of a single-period structure of a one-dimensional grating metasurface constructed by the present invention based on QGM;

[0041] Figure 2 is a dispersion relation diagram of the one-dimensional grating metasurface of the present invention without perturbation δ (δ = 0) and with perturbation δ (δ = 9 nm);

[0042] Figure 3 is a schematic diagram of the energy band folding process of the present invention;

[0043] Figure 4 is the transmission spectrum supported by the one-dimensional grating metasurface sensor of the present invention in different refractive index environments;

[0044] Figure 5 is the angular transmission spectrum supported by the one-dimensional grating metasurface sensor of the present invention at different incident wavelengths;

[0045] Figure 6 is the angular transmission spectrum of the one-dimensional grating metasurface sensor measured by the present invention when the incident wavelength is fixed at 1570 nm and the sensor is in different refractive index environments;

[0046] Figure 7 is a schematic diagram of the angle measurement system of the present invention;

[0047] Figure 8 is the result diagram obtained by the angle measurement system of the present invention when measuring different refractive index environments;

[0048] Figure 9 is the result diagram obtained by the angle measurement system of the present invention when measuring different refractive index environments at a fixed angle.

[0049] In the drawings, 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; 7 is a power meter.

[0050] The distances or sizes between each part are exaggerated for showing the positions of each part, and the schematic diagrams are only for illustration. Detailed implementation mode

[0051] It should be noted that the following detailed description is illustrative and is 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 meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0052] As introduced in the background art, the purpose of the present invention is to overcome the deficiencies existing in the above-mentioned prior art, and to provide a molecular interaction instrument based on a all-dielectric optical metasurface and an implementation method, which utilizes high-Q-factor optical resonance modes and angle scanning technology to achieve low-cost and high-sensitivity molecular interaction detection.

[0053] Example 1

[0054] In a typical implementation mode of the present invention, this embodiment discloses a molecular interaction instrument based on a all-dielectric optical metasurface, including: a all-dielectric optical metasurface structure sensor and an angle measurement system based on a continuous wave laser; wherein, there is a geometric perturbation 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 so that an affinity layer molecule coupled with the target molecule to be detected is fixed 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 molecule.

[0055] The following is a detailed description.

[0056] The all-dielectric optical metasurface structure sensor is constructed by using all-dielectric materials to construct an optical metasurface structure, which supports high-quality factor quasi-guided mode resonance modes; a double grating metasurface is constructed on a sample with a low refractive index substrate at the lower layer and a high refractive index material at the upper layer, and a periodic structure is composed of two asymmetric grating bars; there is a geometric perturbation in its metasurface structure, so that the metasurface structure undergoes a period doubling effect.

[0057] The all-dielectric optical metasurface structure mentioned in this embodiment adopts an all-dielectric optical structure, which supports high-quality factor quasi-guided modes (Quasi guided modes, abbreviated as QGM) resonance modes. The QGM mode introduces geometric perturbations in the sub-wavelength periodic structure, causing the period to double to the wavelength scale. In this way, the waveguide mode energy band supported in the original sub-wavelength structure will appear above the light ray due to the folding of the Brillouin zone of the periodic structure, thus forming the QGM leakage mode.

[0058] In this embodiment, the all-dielectric optical metasurface structure is introduced from the aspects of material system, structural characteristics and optical characteristics respectively:

[0059] (1)Material system: The all-dielectric optical structure material system that supports the QGM mode includes, but is not limited to, high-refractive-index (refractive index greater than 2.0) dielectric materials on sapphire or silica substrates, including silicon, silicon nitride, and III-V semiconductors, etc.

[0060] 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 alumina.

[0061] (2)Structural characteristics: The introduction of geometric perturbation causes the period of the entire structure to jump, thereby realizing the contraction of the first Brillouin zone and the folding of the energy band.

[0062] In this embodiment, the periodic structure can be a one-dimensional periodic grating array, or a two-dimensional periodic column array, or a two-dimensional periodic air hole array in a high-refractive-index dielectric film, etc. The introduction of the period-doubling perturbation can be achieved by changing the width of a specific grating bar, column, or air hole, 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, thus 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 magnitude of the perturbation.

[0063] (3)Optical characteristics: The quality factor of the QGM mode can be controlled by the amplitude of the geometric perturbation, thus enabling high-quality factor characteristics; in addition, the QGM still maintains the steep dispersion energy band curve in the original sub-wavelength structure, so the resonant wavelength can be tuned by changing the incident angle.

[0064] In this embodiment, since the quasi-guided mode still maintains the waveguide mode dispersion curve before the introduction of the period-doubling perturbation, but this dispersion curve is folded above the light dispersion curve, therefore, for a 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 beam.

[0065] In this embodiment, a double-grating metasurface is constructed on a sample with a sapphire substrate and a silicon-based material on the upper layer. Its basic unit (i.e., a single periodic structure) is composed of two asymmetric grating bars, as Figure 1 shown. The center distance between the two grating bars is p / 2, where p is the period of the basic unit in the X direction, and the heights of the two grating bars are the same, but their widths are different. The difference in the widths of the two grating bars in a single periodic structure is defined as δ.

[0066] When the widths of the two grating bars are equal (i.e., δ = 0), this structure mutates into a single grating structure, and the period shrinks to 0.5p. At this time, although the metasurface is still a periodic structure, its period is much smaller than the laser wavelength used, so it still supports tightly bound guided wave modes. The energy band is located below the light ray, and this mode cannot be coupled to free space. Figure 2 The figure shows the dispersion relation diagrams of a one-dimensional grating metasurface without perturbation δ (δ = 0) and with perturbation δ (δ = 9nm). In the figure, X is the boundary point in the k x direction of the first Brillouin zone when the basic unit period is p / 2, and X’ is the boundary point in the k x direction of the first Brillouin zone when the basic unit period is p. Г is the center of the Brillouin zone, corresponding to the zero wave vector point. As can be seen from Figure 2 the black solid line in the figure, the dispersion relation of the single grating metasurface is in a bound state at this time and cannot be excited from the far field.

[0067] When a periodic perturbation (i.e., δ ≠ 0) is introduced on the basis of the traditional single grating metasurface, the period doubles to p, which makes the originally guided mode in the bound state fold into the continuous domain, forming a quasi-guided mode. As shown by the dotted line in Figure 2 , when the width of every second grating is increased (δ = 9nm), the period of the basic unit is doubled in the X direction, which in turn causes the energy band to fold in the k x direction, and at the same time, the Q factor of the QGM folded into the continuous domain can still maintain a high level. Figure 3 Figure is a schematic diagram of the folding of the energy band in a Brillouin zone, explaining the specific process of the energy 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 bands originally distributed in the high wave vector region will be folded into the low wave vector region.

[0068] The schematic diagram of the structure of a single unit of the double grating metasurface sensor constructed based on the QGM mode in this embodiment is as shown in Figure 1 . The specific parameters in the figure 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 periodic perturbation is δ = 9nm. These structural parameters can be changed according to needs to scale the size of the structure, so that the grating metasurface sensor can be matched to the wavelength required for research.

[0069] The double grating metasurface sensor designed in this embodiment can support resonances with high quality factors in a specific wavelength range. The dispersion curve of the double grating metasurface sensor is calculated based on the finite element method simulation, and the results are as shown in Figure 2As shown by the black dashed line in []. It can be seen that this dispersion curve is very steep. Therefore, the dual-grating metasurface sensor can support resonances in a relatively large wavelength range, bringing great flexibility to subsequent measurements. Figure 4 This is the result of numerically simulating the transmission spectra 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, the resonance position will shift to a larger wavelength, thus re-satisfying the resonance condition. Further, the angular transmission spectra of the dual-grating metasurface sensor were also simulated and calculated, and the results are as Figure 5 shown. It can be seen that the dual-grating metasurface sensor can support resonances at different wavelengths under different incident angles. This provides more flexibility for the selection of the laser wavelength in the subsequent angle measurement system.

[0070] Figure 6 This is the result of numerically simulating the angular transmission spectra 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, the resonance position will shift to a smaller incident angle, thus re-satisfying the resonance condition. In this way, the concentration of the molecule to be detected can be quantitatively characterized by the magnitude of the shift of the resonance angle.

[0071] Assume that the high refractive index material used in constructing the dual-grating metasurface sensor is silicon. This material can generate various functional groups such as hydroxyl, amino, and carboxyl groups during surface modification. Its surface can immobilize a variety of different probe molecules, thereby increasing the types of molecules that can be detected and enabling the detection of a variety of biomolecules. After further functionalizing the above dual-grating metasurface sensor, specific probe molecules are fixed on the surface of the dual-grating metasurface sensor, and then the target molecules can be measured. The coupling of target molecules with different concentrations to the probe molecules 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, thus causing the resonance position to shift on the angular transmission spectrum. As Figure 6 shown, different refractive index environments cause different degrees of blue shifts in the angular transmission spectrum.

[0072] In this embodiment, the functionalization process mainly involves chemically treating the surface of the metasurface sensor, including hydroxylating the metasurface sensor, then activating it with 3-aminopropyltriethoxysilane, and immobilizing biotin probe molecules. Thereby, various functional groups such as hydroxyl, amino, and carboxyl groups are generated on the surface of the metasurface sensor, so as to immobilize different probe molecules, realize the detection of a variety of biomolecules, and expand the scope of surface functionalization of the sensor.

[0073] Due to the high stability of all-dielectric materials, the metasurface sensor can maintain its physical properties even after multiple repeated uses. After cleaning the surface with concentrated sulfuric acid or oxygen plasma and then re-performing surface modification, reuse can be achieved. Even the same metasurface sample can be used to detect different target molecules, greatly reducing the detection cost.

[0074] As Figure 7 shown, the angle measurement system based on a continuous-wave laser consists of a continuous-wave laser 1 with a 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; among them, after the functionalization process of the all-dielectric 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 molecule to be detected is introduced into the liquid chamber 4. Based on the angle scanning technology, the effect of molecular interaction is detected.

[0075] Specifically, the continuous-wave laser 1 with a single-wavelength output can use a continuous-wave laser with a single-wavelength output, such as the distributed feedback laser mode used in optical communication; the receiving end of the system can use a power meter 7 to detect the change in transmittance, such as a low-cost power meter in an optical network; the rotatable sample stage 3 can use an electric rotation platform or a manual rotation 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 detected; the focusing lens 5 is used to converge the incident light.

[0076] During the detection process, the incident angle is adjusted through the electric rotation platform to make the metasurface structure in the resonant state, at which time the transmittance is the lowest. When molecular interaction occurs, the slight change in refractive index caused will make the structure deviate from the resonant state, resulting in a change in transmittance. By measuring the change in transmittance, the occurrence of molecular interaction can be monitored in real time. Moreover, using an affordable continuous-wave laser and power meter instead of an expensive spectrometer greatly reduces the equipment cost and has better universality, and can be applied in large-scale detections.

[0077] Example 2

[0078] In a typical implementation manner of the present invention, this embodiment discloses a method for implementing a molecular interaction instrument based on an all-dielectric optical metasurface, which includes two characterization methods: the angle transmission spectrum measurement method and the fixed angle measurement method. Taking the fixed output wavelength of the laser as 1570 nm as an example, they will be introduced one by one below.

[0079] Method 1: Angle transmission spectrum measurement method.

[0080] S1. Preparation of the metasurface sensor: Using a high-refractive-index medium on a low-refractive-index substrate (such as silicon on sapphire, or silicon on fused quartz, etc.), fabricate periodic nanostructures that conform to the QGM working principle based on microfabrication methods.

[0081] S2. Surface functionalization treatment: Perform functionalization treatment on the fabricated silicon-based double-grating metasurface sensor to immobilize probe molecules on its surface. The steps are hydroxylation, activation treatment using (3-aminopropyl) triethoxysilane (APTES), and immobilization of biotin probe molecules in sequence.

[0082] S3. Loading the sample: Place the functionalized metasurface sensor on a rotatable sample stage with a liquid chamber, and introduce a buffer solution into the liquid chamber.

[0083] S4. Laser setting: Set the output wavelength of a continuous-wave laser with single-wavelength output to 1570 nm. 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 normal incidence, so that the QGM mode is excited when the incident angle is positive.

[0084] S5. Angle scanning: Rotate the sample stage, adjust the incident angle through the rotating sample stage platform, and at the same time record the power value of the power meter to plot the angle transmission spectrum.

[0085] S6. Detection of target molecules: Introduce a solution containing target molecules (such as streptavidin) into the liquid chamber, repeat S5, and record the change in the power value of the power meter. Different concentrations of target molecules will cause different degrees of displacement of the angle transmission spectrum, and the concentration of target molecules is quantitatively detected by the magnitude of the displacement.

[0086] Figure 8 Shows a simulation diagram of the measurement results of different concentrations of target molecules using Method 1. 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 on the sensor surface and causing a shift in the angle transmission spectrum of the double-grating metasurface sensor. The greater the concentration, the greater the increase in the refractive index on the sensor surface, and at the same time, the greater the shift amplitude of the angle transmission spectrum. The concentration of target molecules can be quantitatively judged by the shift of the resonant angle.

[0087] Method 2: Fixed-angle measurement method.

[0088] S1. Preparation of the metasurface sensor: Using a high-refractive-index medium on a low-refractive-index substrate (such as silicon on sapphire, or silicon on fused quartz, etc.), fabricate periodic nanostructures that conform to the QGM working principle based on microfabrication methods.

[0089] S2. Surface functionalization treatment: The fabricated silicon-based double-grating metasurface sensor is functionally treated to immobilize probe molecules on its surface. It includes hydroxylation, activation with (3-aminopropyl) triethoxysilane (APTES), and immobilization of biotin probe molecules in sequence.

[0090] S3. Loading the sample: The functionally treated metasurface sensor is placed on a rotatable sample stage with a liquid chamber, and a buffer solution is introduced into the liquid chamber.

[0091] S4. Laser setting: Set the output wavelength of a continuous-wave laser with single-wavelength output to 1570 nm. 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 normal incidence, so as to excite the QGM mode when the incident angle is positive.

[0092] S5. Angle adjustment: Rotate the sample stage, and adjust the incident angle through the rotating sample stage platform. Find the rotation angle corresponding to the minimum reading of the power meter, and fix the sample stage at this angle.

[0093] S6. Detection of target molecules: Introduce a solution containing target molecules into the liquid chamber, and observe the change in the reading of the power meter; detect target molecules with different concentrations, and repeat S5.

[0094] As the concentration of the target molecules increases, the reading of the power meter will gradually increase, and the concentration of the target molecules is quantitatively detected through the change in the reading.

[0095] Figure 9 The figure shows the results of detecting target molecules with different concentrations using Method 2. When the liquid to be detected contains target molecules, the probe molecules on the sensor will couple with them, increasing the refractive index on the sensor surface, and then causing the resonance position of the sensor to shift. At this time, the reading of the power meter will increase. The greater the concentration, the greater the deviation of the resonance position from 1570 nm, and at the same time, the reading of the power meter will further increase. At the same time, the real-time performance of Method 2 is higher than that of Method 1.

[0096] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A molecular interaction instrument based on an all-dielectric optical metasurface, characterized in that, Comprising: A sensor based on an all-dielectric optical metasurface structure and an angle measurement system based on a continuous-wave laser; Among them, the sensor based on the all-dielectric optical metasurface structure uses all-dielectric materials to construct an optical metasurface structure, supports a quasi-guided mode resonance mode with a high quality factor, and there is a geometric perturbation in the metasurface structure, causing a period-doubling effect in the metasurface structure; Functionalize the sensor based on the all-dielectric optical metasurface structure to fix an affinity layer molecule coupled with the target molecule to be detected on its surface, and put the functionalized sensor based on the all-dielectric optical metasurface structure into the angle measurement system based on the continuous-wave laser to detect the target molecule; After the surface of the sensor based on the all-dielectric optical metasurface structure is functionalized, a variety of functional groups are generated, so as to fix different probe molecules and realize the detection of a variety of biomolecules; the functional groups include one or several of hydroxyl, amino, and carboxyl; The angle measurement system based on the continuous-wave laser is successively 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; After the functionalization of the sensor based on the all-dielectric optical metasurface structure is completed, it is placed on the rotatable sample stage with a liquid chamber. A liquid containing the target molecule to be detected is introduced into the liquid chamber, and based on the angle scanning technique, the effect of molecular interaction is detected.

2. The molecular interaction instrument based on all-dielectric optical metasurface according to claim 1, wherein For the sensor based on the all-dielectric optical metasurface structure, 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 composed of two asymmetric grating bars.

3. The molecular interaction instrument based on the all-dielectric optical metasurface according to claim 2, wherein The periodic structure is a one-dimensional periodic grating array, or a two-dimensional periodic column array, or a two-dimensional periodic air hole array in a high-refractive-index dielectric film.

4. The molecular interaction instrument based on all-dielectric optical metasurface according to claim 2, characterized in that, The two asymmetric grating bars are specifically that the heights of the two grating bars are the same, but their widths are different; the difference in the widths of the two grating bars 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, wherein The center distance between the two asymmetric grating bars in a single periodic structure is half of the single-period length.

6. Method for implementing a molecular interaction instrument based on an all-dielectric optical metasurface, using the molecular interaction instrument based on an all-dielectric optical metasurface according to any one of claims 1-5, characterized in that, Comprising: Functionalize the sensor based on the all-dielectric optical metasurface structure to complete the fixation of the probe molecule on its surface; Put the functionalized sensor based on the all-dielectric optical metasurface structure between the sample stage and the liquid chamber, and introduce a buffer solution into the liquid chamber; Fix the output wavelength of the continuous-wave laser with single-wavelength output at a set value; Rotate the sample stage to adjust the incident angle, record the power value of the power meter, and plot the angle transmission spectrum; Introduce a liquid containing the target molecule to be detected into the liquid chamber, rotate the sample stage to adjust the incident angle, record the power value of the power meter, plot the angle transmission spectrum, and record the change in the power value of the power meter; Target molecules with different concentrations will cause different degrees of displacement of the angle transmission spectrum, and the concentration of the target molecule is quantitatively detected by the magnitude of the displacement.

7. Method for implementing a molecular interaction instrument based on an all-dielectric optical metasurface, using the molecular interaction instrument based on an all-dielectric optical metasurface according to any one of claims 1-5, characterized in that, Comprising: Functionally process the sensor based on the all-dielectric optical metasurface structure to complete the fixation of the probe molecule on its surface; Put the functionalized sensor based on the all-dielectric optical metasurface structure between the sample stage and the liquid chamber, and introduce a buffer solution into the liquid chamber; Fix the output wavelength of the continuous-wave laser with single-wavelength output at the set value; Rotate 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; Introduce the 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 is quantitatively detected through the change in the power value.

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