Micro-ring resonator biosensor based on optical mechanical coupling enhancement

Abstract

The invention discloses a micro-ring resonator biosensor based on optical mechanical coupling enhancement, the micro-ring resonator biosensor comprises a micro-ring resonator and a functional coating, the micro-ring resonator comprises a high-quality factor micro-ring and a bus waveguide, the surface of the micro-ring is covered with a flexible vibration film, and the micro-ring is used for generating high-frequency mechanical vibration; a nanometer gap is arranged between the high-quality-factor micro-ring and the bus waveguide and is used for enhancing the opto-mechanical coupling strength. The multifunctional coating is formed on the surface of the micro-ring coated with the flexible vibration film, comprises a silane coupling agent and an EDC / NHS coupling agent, and is used for fixing a specific antibody. According to the micro-ring resonator biosensor, an optical-mechanical coupling mechanism is innovatively introduced, optical sensing and mechanical vibration modes are combined, the signal enhancement capability and the anti-interference performance are remarkably improved, and therefore high-sensitivity detection of target specific molecules is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of biosensing detection, and particularly relates to a micro-ring resonator biosensor based on enhanced optomechanical coupling. Background Art

[0002] For many diseases, whether they are infectious diseases such as various viral infections and bacterial infections, or autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus, at the initial stage of the disease, the human immune system will produce specific antibodies against pathogens or abnormal autoantigens. These specific antibodies are like the "fingerprints" of the disease, with a high degree of specificity and can accurately point to the corresponding pathogenic factors. Accurately detecting these specific antibodies means that the signal of the disease can be captured when the disease is still in its infancy, the clinical symptoms are not typical or even have not appeared.

[0003] High Mobility Group Protein 1 (HMGB1) belongs to the high mobility group protein family. Inside the cell nucleus, HMGB1 binds to DNA and participates in life activities such as DNA recombination, repair, gene transcriptional regulation, cell replication, and differentiation and maturation. When DNA is damaged, HMGB1 will be recruited to the damage site and interact with other DNA repair proteins to promote the damage repair process. Outside the cell, HMGB1 is a key mediator of the inflammatory response and participates in the regulation of the immune response. In addition, in a variety of inflammatory diseases, the levels of HMGB1 in the blood and tissues will increase significantly, aggravating the inflammatory response; HMGB1 also plays a complex role in the occurrence, development, and metastasis of tumors and is a key biomarker for inflammatory diseases and various tumors. Therefore, the accurate and sensitive detection of specific antibodies such as HMGB1 is of great significance for the early diagnosis and treatment of diseases. However, the current mainstream detection methods (such as enzyme-linked immunosorbent assay, mass spectrometry, etc.) have problems such as complex operation, long detection time, and low sensitivity, and it is difficult to meet the requirements of rapid and portable detection.

[0004] Micro-ring resonators have become a research hotspot for a new generation of biosensors due to their high quality factor (Q factor) and strong optical field enhancement effect. However, traditional micro-ring resonators mainly rely on the weak cladding evanescent field to interact with the detected biomolecules, and the interaction between the optical field and the sensing medium is weak, resulting in low sensing sensitivity and it is difficult to detect low-concentration biomolecules. In addition, limited by the weak interaction between the optical field and the sensing medium, it is difficult to achieve ultra-high refractive index sensitivity. In view of this, there is an urgent need in the art for a device that can accurately and ultrasensitively detect specific antibodies. Summary of the Invention

[0005] To overcome the above problems in the prior art, the object of the present invention is to provide a micro-ring resonator biosensor based on enhanced optomechanical coupling, which adopts an innovative design combining a micro-ring resonator with a multi-layer nano-functionalized coating to achieve accurate and ultrasensitive detection of specific antibodies. The micro-ring resonator biosensor captures the frequency drift of mechanical vibrations caused by weak molecule-surface interactions and combines it with the optical mode modulation effect to achieve high-fold amplification and precise measurement of signals. The present invention innovatively introduces an optomechanical coupling mechanism, combines optical sensing with mechanical vibration modes, significantly improves the signal enhancement ability and anti-interference performance, and thus realizes highly sensitive detection of specific antibodies.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In the first aspect of the present invention, there is provided a micro-ring resonator biosensor based on enhanced optomechanical coupling, which includes: a micro-ring resonator and a functionalized coating. The micro-ring resonator includes a micro-ring with a high quality factor and a bus waveguide. Among them, the surface of the micro-ring is covered with a flexible vibration film for generating high-frequency mechanical vibrations; a nano-gap is provided between the micro-ring with a high quality factor and the bus waveguide for enhancing the optomechanical coupling strength; the multi-functional coating is formed on the surface of the micro-ring covered with the flexible vibration film and includes a silane coupling agent and an EDC / NHS coupling agent for immobilizing specific antibodies.

[0008] Further, the micro-ring is based on an SOI wafer, and the waveguide pattern is generated by photolithography technology and prepared by using a reactive ion etching process.

[0009] Further, the thickness of the flexible vibration film is less than 50 nm.

[0010] Further, the flexible vibration film is a lithium niobate film.

[0011] Further, the nano-gap between the micro-ring and the bus waveguide is set to 160 nm.

[0012] Further, the silane coupling agent is 3-aminopropyltriethoxysilane.

[0013] In the second aspect of the present invention, there is provided a preparation method of the micro-ring resonator biosensor based on enhanced optomechanical coupling, which includes the following steps:

[0014] S1: Using an SOI wafer as a substrate, uniformly coating a photoresist on the surface of the wafer, and accurately transferring the waveguide pattern to the photoresist by photolithography technology;

[0015] S2: Adopting a reactive ion etching process, etching the wafer according to the waveguide pattern on the photoresist to remove the excess silicon material and preparing the micro-ring and the bus waveguide.

[0016] S3: Deposit a flexible vibrating thin film on the surface of the micro-ring using chemical vapor deposition technology, such that the thickness of the flexible vibrating thin film is less than 50 nm;

[0017] S4: Place the device obtained in step S3 in a piranha solution for surface -OH group activation, then soak it in a silane coupling agent buffer solution for a certain period of time, add an EDC / NHS coupling agent to form a functionalized coating, thereby obtaining a micro-ring resonator biosensor based on enhanced optomechanical coupling.

[0018] Further, in step S1, etch the wafer according to the waveguide pattern on the photoresist to remove the excess silicon material, such that a 160 nm gap is provided between the micro-ring and the bus waveguide.

[0019] Further, in step S4, it also includes adding BSA to block potential active sites after adding the EDC / NHS coupling agent, and then rinsing with a PBS buffer solution to remove unbound substances and residual reagents.

[0020] The third aspect of the present invention provides a method for detecting the concentration of a target specific antibody using the micro-ring resonator biosensor based on enhanced optomechanical coupling, which includes the following steps:

[0021] S1: Add an appropriate amount of the target specific antibody solution to the surface of the micro-ring of the micro-ring resonator biosensor based on enhanced optomechanical coupling, ensuring that the specific antibody can fully contact the functionalized coating on the surface of the micro-ring;

[0022] S2: Let it stand for a certain period of time to stably bind the target specific antibody to the surface of the micro-ring;

[0023] S3: Use a spectrometer to monitor the optical resonance wavelength drift of the micro-ring resonator biosensor and record the wavelength data at different time points;

[0024] S4: Simultaneously use a frequency analyzer to extract the mechanical frequency drift signal generated by antibody binding of the micro-ring resonator biosensor;

[0025] S5: Integrate and analyze the optical resonance wavelength drift data and mechanical frequency drift data collected by the spectrometer and the frequency analyzer, and combine the calibration curve established in advance through standard samples. The calibration curve covers the relationship between the optical and mechanical signal changes corresponding to different concentrations of the target specific antibody. Through data fitting and comparison, calculate the concentration of the target specific antibody;

[0026] S6: Use the reference channel data built in the micro-ring resonator optical sensor to correct the error of the calculation result.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) By introducing a microring resonator, signal amplification is achieved through the coordinated change of the optical mode and the mechanical vibration mode. Moreover, a nanogap is set between the microring and the bus waveguide, significantly enhancing the optomechanical coupling strength and greatly improving the detection sensitivity.

[0029] (2) Through the multifunctional coating design, by combining the functional modification of metal-organic frameworks and antibodies, double-layer modification is increased. The ammonia group is modified by a silane coupling agent, and specific antibodies are covalently fixed by combining the EDC / NHS activation method, forming a double-layer functional modification. This design not only ensures the efficient capture of target molecules but also effectively reduces non-specific adsorption.

[0030] (3) Through the dual-channel signal output, the optical resonance wavelength drift and the mechanical frequency drift are monitored simultaneously, enhancing the anti-interference ability and further improving the detection accuracy.

[0031] (4) Adopting a chip-level integration scheme significantly reduces the manufacturing cost of the sensor, improves portability, and meets the application requirements of multiple scenarios.

[0032] (5) The optomechanical signal is enhanced. When the target molecule binds to the surface of the microring, the vibration mode of the optomechanical coupling resonator is excited, resulting in a coordinated drift of the optical mode and the mechanical vibration frequency, significantly enhancing the signal intensity. The frequency drift of the optomechanical resonance has a non-linear enhancement relationship with the target molecule concentration. By detecting the change in the optical resonance wavelength with a spectrometer and extracting the mechanical signal by combining a frequency analyzer, dual high-precision detection is achieved. The detection limit of the sensor reaches 0.13 μg / ml (4.99 nM), the sensitivity is as high as 1.75 pm / nM, and the detection error is controlled within 2.6%, ensuring the high precision and reliability of molecular detection. Description of the Drawings

[0033] Figure 1 is a schematic diagram of the overall structure of the microring resonator biosensor based on enhanced optomechanical coupling provided by an embodiment of the present invention.

[0034] Figure 2 is a front view of the substrate of the microring resonator biosensor provided by an embodiment of the present invention.

[0035] Figure 3 is a schematic diagram of the structure above the microring resonator substrate of the microring resonator biosensor provided by an embodiment of the present invention.

[0036] Figure 4 is a schematic diagram of the functionalized coating silane coupling agent and the EDC / NHS coupling agent activation modification layer of the microring resonator biosensor provided by an embodiment of the present invention.

[0037] Figure 5 It is a schematic diagram of the working principle of the micro-ring resonator biosensor based on enhanced optomechanical coupling provided by an embodiment of the present invention.

[0038] Figure 6 It is a flow chart of the surface functionalization modification step.

[0039] Figure 7 It is a graph of the spectral transmission measurement results of the micro-ring resonator biosensor at different concentrations.

[0040] In the figure: 1 - Micro-ring with high quality factor; 2 - Bus waveguide; 3 - Nano-gap; 4 - Substrate; 5 - Functional coating. Specific embodiments

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments, but the present invention is not limited thereto.

[0042] The present invention provides a micro-ring resonator biosensor based on enhanced optomechanical coupling, which includes: a micro-ring resonator and a functional coating. The micro-ring resonator includes a micro-ring with high quality factor and a bus waveguide. Among them, the surface of the micro-ring is covered with a flexible vibrating film for generating high-frequency mechanical vibration; preferably, the flexible vibrating film is a lithium niobate film. A nano-gap is provided between the micro-ring with high quality factor and the bus waveguide for enhancing the optomechanical coupling strength and improving the sensitivity and response speed of the sensor; preferably, the nano-gap between the micro-ring and the bus waveguide is set to 160 nm. The multi-functional coating is formed on the surface of the micro-ring covered with the flexible vibrating film, including a silane coupling agent and an EDC / NHS coupling agent for fixing specific antibodies. Preferably, the silane coupling agent is 3-aminopropyltriethoxysilane.

[0043] The following embodiments implement the micro-ring resonator biosensor of the present invention using high mobility group protein 1 (HMGB1) as the target molecule.

[0044] It should be noted that the experimental methods used in the embodiments of the present invention are all conventional methods unless otherwise specified; the reagents and materials used can be obtained through commercial channels unless otherwise specified.

[0045] Example 1. Preparation of the micro-ring resonator

[0046] The micro-ring resonator is fabricated using an SOI (Silicon-On-Insulator) wafer as the substrate. Figure 2The front view of the substrate is shown. First, a photoresist is uniformly coated on the surface of the wafer. Then, using photolithography technology, an exposure operation is carried out according to the pre-designed waveguide pattern, so that the waveguide pattern is accurately transferred onto the photoresist. Subsequently, a reactive ion etching (RIE) process is adopted to etch the wafer according to the waveguide pattern on the photoresist, removing the excess silicon material, and thus successfully fabricating the micro-ring and bus waveguides. The structure above the micro-ring resonator substrate is as shown in Figure 3 During this process, the process parameters are strictly controlled to ensure that the radius of the micro-ring resonator is 100 μm, and the size of the bus waveguide reaches 220 nm in height and 600 nm in width.

[0047] After the preliminary fabrication of the micro-ring resonator is completed, a lithium niobate thin film is deposited on the surface of the micro-ring as a flexible vibration film by chemical vapor deposition (CVD) technology. By finely adjusting the various parameters of the CVD process, including temperature, gas flow rate, and deposition time, etc., it is ensured that the film thickness is less than 50 nm.

[0048] Example 2. Functionalization of the micro-ring resonator

[0049] First, the device prepared in Example 1 is cleaned with IPA to remove surface impurities and contaminants, and then dried. Then it is placed in the piranha solution for a certain time, preferably 30 seconds, for surface -OH group activation to provide active sites for subsequent modification reactions.

[0050] After taking the device out of the piranha solution, it is soaked in 0.2M APTES buffer solution for a certain time, preferably 10 minutes. During this process, the ethoxy groups in APTES molecules will react with the hydroxyl groups on the surface of the sensor to generate -NH 2 groups and Si - O - Si bonds, thus realizing the preliminary modification of the sensor surface.

[0051] After that, 0.2 mol / L EDC / NHS coupling agent is added to bond the carboxylic acid groups using the EDC / NHS coupling agent, and the anti - HMGB1 chemical bond is bonded to the surface of the sensor, so that the HMGB1 antibody can be firmly fixed on the surface of the micro-ring resonator biosensor. Preferably, the curing time is 5 minutes. In this step, EDC and NHS work together to activate the carboxyl group of the antibody and promote its formation of a covalent bond with the existing -NH 2 groups on the sensor surface. Figure 4 The functionalized coating of the silane coupling agent and the EDC / NHS coupling agent activation modification layer is shown in

[0052] To prevent non-specific adsorption caused by unreacted active sites, a blocking treatment is carried out with 0.2M BSA. BSA can effectively block these potential active sites and reduce background interference.

[0053] Finally, thoroughly clean the sensor with PBS buffer to remove unbound substances and residual reagents, ensuring the purity and stability of the sensor surface. This complete functionalization process improves the affinity and sensitivity of the sensor to HMGB-1 molecules, laying a solid foundation for effective detection. The overall structure of the fabricated optical waveguide biosensor based on the micro-ring resonator structure is as Figure 1 shown.

[0054] Example 3. Detection process

[0055] The method for detecting the concentration of the target specific antibody using the above-mentioned micro-ring resonator biosensor enhanced by optomechanical coupling includes the following steps:

[0056] S1: Add an appropriate amount of the target specific antibody solution to the surface of the micro-ring of the micro-ring resonator biosensor enhanced by optomechanical coupling that has been functionalized and integrated into the detection system, ensuring that the antibody can fully contact the functionalized coating on the micro-ring surface, and the volume and concentration of the solution need to be precisely controlled according to the previous calibration and experimental design. Generally, the appropriate concentration gradient can be determined by referring to the detection linear range and sensitivity of the sensor.

[0057] S2: Let it stand for a certain period of time to enable the stable binding of the target specific antibody to the micro-ring surface through covalent bonds or other means. This time needs to be optimized according to the reaction kinetics between the antibody and the coating, and can be determined by measuring the binding efficiency at different times through preliminary experiments. Generally, it is between several minutes and dozens of minutes. At the same time, maintain the stability of the detection environment, such as keeping constant conditions like temperature, humidity, and pH to avoid interference from external factors in the antibody-sensor binding process.

[0058] S3: Use a spectrometer to monitor the optical resonance wavelength drift of the micro-ring resonator biosensor and record the wavelength data at different time points. Since the binding of the target specific antibody will cause a change in the refractive index of the medium around the micro-ring resonator, which in turn leads to a change in the optical resonance wavelength, the optical signal related to the antibody binding is obtained by precisely measuring the tiny change in the wavelength.

[0059] S4: At the same time, use a frequency analyzer to extract the mechanical frequency drift signal generated by the micro-ring resonator biosensor due to antibody binding. Since the interaction between the antibody and the micro-ring surface causes a change in the mechanical vibration frequency of the flexible vibration film, the frequency analyzer can capture this subtle frequency change to obtain the mechanical signal.

[0060] S5: Integrate and analyze the optical resonance wavelength drift data and mechanical frequency drift data collected by the spectrometer and frequency analyzer. Combine with the calibration curve established in advance through standard samples, where the calibration curve needs to cover the relationship between the optical and mechanical signal changes corresponding to target specific antibodies at different concentrations. Calculate the concentration of the target specific antibody through data fitting and comparison.

[0061] S6: Use the reference channel data built into the sensor to correct the error of the calculation result. The reference channel can monitor in real time the signal changes caused by environmental factors (such as temperature fluctuations, equipment noise, etc.), and based on this, compensate and correct the detection result to ensure that the finally obtained antibody concentration detection result has high accuracy and reliability.

[0062] In a specific embodiment, successively drop different concentrations of HMGB1 standard solutions onto the surface of the functionalized micro-ring resonator biosensor. Set 3 parallel samples for each concentration to ensure that the solution evenly covers the micro-ring, and the volume of each drop is 10 μL.

[0063] After the dropping is completed, place the sensor in an environment with stable temperature and humidity and let it stand for 30 minutes to allow the HMGB1 molecules to fully bind to the antibodies on the sensor surface.

[0064] At the same time, turn on the spectrometer and frequency analyzer. The spectrometer scans the optical resonance wavelength drift of the micro-ring resonator at a resolution of 0.1 nm in the wavelength range of 1500 - 1600 nm, records data every 5 minutes, and continuously records for 30 minutes. The frequency analyzer synchronously monitors the mechanical frequency drift signal of the micro-ring resonator, sets the frequency measurement accuracy to 1 Hz, and also records data every 5 minutes. Figure 5 The working schematic diagram of the micro-ring resonator biosensor is shown in.

[0065] Example 4. Data analysis of the detection results

[0066] For the optical resonance wavelength drift data collected by the spectrometer, calculate the average wavelength drift value (Δλ) of each concentration sample at different time points, and plot the standard curve of HMGB1 concentration vs. average wavelength drift value. Determine the quantitative relationship between the two through linear regression analysis.

[0067] For the mechanical frequency drift signal obtained by the frequency analyzer, calculate the average mechanical frequency drift value (Δf) of each concentration sample. Similarly, plot the standard curve of HMGB1 concentration vs. average mechanical frequency drift value and conduct linear regression analysis.

[0068] Using the reference channel data built in the sensor, error correction is performed on the measurement results of the optical resonance wavelength drift and the mechanical frequency drift. According to the corrected results and in combination with the above standard curve, the concentration of HMGB1 in the unknown sample is calculated.

[0069] Example 5. Verification of Experimental Results and Expected Technical Effects

[0070] (1) Results of Optical Resonance Wavelength Drift

[0071] By detecting different concentrations of HMGB1 standard solutions, the obtained optical resonance wavelength drift data shows that as the concentration of HMGB1 increases, the optical resonance wavelength of the micro-ring resonator exhibits an obvious red-shift phenomenon. Figure 7 (a)-(d) respectively show the spectral transmission measurement results of the micro-ring resonator biosensor at (a) 1 μg / ml, (b) 2 μg / ml, (c) 5 μg / ml, and (d) 10 μg / ml. Figure 7 (e) shows the spectral shift of the micro-ring resonator biosensor for measuring the change in analyte concentration. It can be seen that the spectral shift has a linear relationship with the analyte concentration. In the concentration range of 0.1 - 10 μg / mL, the optical resonance wavelength drift (Δλ) and the HMGB1 concentration (C) show a good linear relationship, and the linear regression equation is Δλ = 0.15C + 0.02 (R 2 = 0.98), indicating that the sensor can effectively detect the change in HMGB1 concentration by monitoring the optical resonance wavelength drift, achieving a high sensitivity, which is consistent with the expected sensitivity improvement effect.

[0072] (2) Results of Mechanical Frequency Drift

[0073] The mechanical frequency drift data shows that after the HMGB1 molecules bind to the sensor surface, the mechanical frequency of the micro-ring resonator also undergoes a significant drift. In the same concentration range, the mechanical frequency drift (Δf) and the HMGB1 concentration (C) show a non-linear enhancement relationship, and the specific functional relationship is Δf = 0.05C2 + 0.01C + 0.005 (R 2 = 0.96). This change in mechanical frequency further corroborates the response ability of the sensor to HMGB1 molecules. By simultaneously monitoring the optical and mechanical signals, the reliability of the detection is enhanced, meeting the expected signal enhancement and anti-interference design goals.

[0074] (3) Detection Limit and Error Analysis

[0075] As Figure 7As shown in (f), after multiple repeated experiments, the actual analyte concentration was compared with the estimated analyte concentration after analyzing the sensor data using the neural network algorithm. The detection limit of this device for HMGB1 was determined to be 0.13 μg / mL (4.99 nM), and within the detection concentration range, the detection error was controlled within 2.6%. This result indicates that the micro-ring resonator biosensor of the present invention can achieve accurate detection of low-concentration specific antibody molecules, meeting the expected technical effect requirements for high sensitivity and high-precision detection, and providing strong technical support for early disease diagnosis.

[0076] It should be noted that the above-described embodiments are only the preferred embodiments of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, several modifications, improvements, and equivalent replacements can be made to the present invention, and these modifications, improvements, and equivalent replacements are also regarded as falling within the protection scope of the claims of the present invention.

Claims

1. A microring resonator biosensor based on photomechanical coupling enhancement, characterized in that: include: A microring resonator and a functionalized coating, wherein the microring resonator comprises a microring with a high quality factor and a busbar waveguide, wherein the surface of the microring is covered with a flexible vibration film for generating high-frequency mechanical vibrations; a nanogap is provided between the microring with a high quality factor and the busbar waveguide for enhancing the strength of the optical mechanical coupling; the multifunctional coating is formed on the surface of the microring covered with the flexible vibration film, and comprises a silane coupling agent and an EDC / NHS coupling agent for fixing specific antibodies.

2. The microring resonator biosensor based on photomechanical coupling enhancement according to claim 1, characterized in that: The micro-ring is based on an SOI wafer, a waveguide pattern is generated by photolithography technology, and is prepared by a reactive ion etching process.

3. The microring resonator biosensor based on photomechanical coupling enhancement according to claim 1, characterized in that: The thickness of the flexible vibration film is less than 50 nm.

4. The microring resonator biosensor based on enhanced photomechanical coupling according to claim 1, characterized in that: The flexible vibration film is a lithium niobate film.

5. The microring resonator biosensor based on enhanced photomechanical coupling according to claim 1, characterized in that: The nanogap between the micro-ring and the busbar waveguide is set to 160 nm.

6. The microring resonator biosensor based on enhanced photomechanical coupling according to claim 1, characterized in that: The silane coupling agent is 3-aminopropyltriethoxysilane.

7. A method for preparing a microring resonator biosensor based on photomechanical coupling enhancement according to claim 1, characterized in that: The steps include: S1: Using SOI wafer as substrate, evenly coat the surface of the wafer with photoresist, and use photolithography technology to accurately transfer the waveguide pattern to the photoresist; S2: Using reactive ion etching technology, the wafer is etched according to the waveguide pattern on the photoresist to remove excess silicon material and prepare micro-rings and busbar waveguides; S3: depositing a flexible vibration film on the surface of the micro-ring using chemical vapor deposition technology, so that the thickness of the flexible vibration film is less than 50 nm; S4: placing the device obtained in step S3 in a piranha solution to activate the surface -OH groups, then soaking it in a silane coupling agent buffer for a certain period of time, adding an EDC / NHS coupling agent to form a functionalized coating, thereby obtaining a microring resonator biosensor based on enhanced photomechanical coupling.

8. The method according to claim 7, characterized in that In step S1, the wafer is etched according to the waveguide pattern on the photoresist to remove excess silicon material, so that a gap of 160 nm is set between the micro-ring and the busbar waveguide.

9. The method according to claim 7, characterized in that: In step S4, BSA is added after the EDC / NHS coupling agent is added to block potential active sites, and then washed with PBS buffer to remove unbound substances and residual reagents.

10. A method for detecting the concentration of a target-specific antibody using the microring resonator biosensor based on photomechanical coupling enhancement according to claim 1, characterized in that: The steps include: S1: adding an appropriate amount of target specific antibody solution to the microring surface of the microring resonator biosensor based on photomechanical coupling enhancement, ensuring that the specific antibody can fully contact the functional coating on the microring surface; S2: Standing for a certain period of time to allow the target-specific antibody to stably bind to the microring surface; S3: using a spectrometer to monitor the optical resonance wavelength drift of the microring resonator biosensor and record wavelength data at different time points; S4: extracting a mechanical frequency drift signal of the microring resonator biosensor due to antibody binding by using a frequency analyzer; S5: integrating and analyzing the optical resonance wavelength drift data and mechanical frequency drift data collected by the spectrometer and the frequency analyzer, and combining the calibration curve established in advance by the standard sample, wherein the calibration curve covers the relationship between the optical and mechanical signal changes corresponding to the target specific antibody at different concentrations, and calculating the concentration of the target specific antibody by data fitting and comparison; S6: using the reference channel data built into the microring resonator optical sensor to perform error correction on the calculation result.

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