An optical fiber integrated micro-cantilever nanometer force biosensor and detection system

Abstract

This application relates to the field of sensor technology, providing an optical fiber integrated microcantilever beam nanomechanical biosensor and detection system. This addresses the problems of existing microcantilever nanomechanical biosensors, which typically require optical lever technology to accurately read microcantilever fluctuations, and the large size, high cost, and high optical loss associated with optical lever demodulation techniques. The system includes: a support base; an optical fiber comprising a cladding and a core, the cladding being disposed on the support base and the core in the middle of the cladding; and a microcantilever beam disposed on the support base and above the cladding, the microcantilever beam having a first end aligned with the core of the optical fiber end face. The microcantilever beam and the optical fiber form a Fabry-Perot interference structure, used to generate Fabry-Perot interference with the optical fiber end face. The distance between the microcantilever beam and the optical fiber end face is the cavity length of the Fabry-Perot interferometer. By monitoring changes in the cavity length, the microcantilever fluctuations can be demodulated and read.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and more specifically, to a fiber-optic integrated microcantilever beam nanomechanical biosensor and detection system. Background Technology

[0002] Antibiotic overuse has become a global public health problem. It is reported that approximately 30-50% of antibiotic prescriptions are unnecessary. Furthermore, the overuse of antibiotics can lead to antibiotics attacking normal flora rather than harmful pathogens, further increasing the risk of antibiotic resistance in harmful pathogens. To address complex and severe bacterial infections or situations where broad-spectrum antibiotics are ineffective, antimicrobial susceptibility testing (AST) is typically performed clinically to identify sensitive antibiotics for precision treatment. However, most AST methods currently available in hospitals (including disk diffusion, dilution, and antibiotic concentration gradient methods) are based on bacterial culture methods. These AST methods are usually time-consuming, requiring 24-48 hours, and are also very expensive. Therefore, they cannot be widely used.

[0003] Microcantilever nanomechanical biosensors are a rapidly developing biosensor technology in recent years. They have advantages such as label-free, real-time, in-situ, and specific detection. They can convert physical, chemical, and biological reaction processes into mechanical signals and record these mechanical signals using optical or electrical means. They have great application potential in bacterial detection and AST (assay-assay).

[0004] However, the construction of existing microcantilever nanomechanical biosensors typically requires the use of optical lever technology to accurately read microcantilever fluctuations (to obtain the activity of bacteria on the microcantilever). To achieve precise optical lever amplification, the detection equipment used in microcantilever nanomechanical biosensors is generally bulky and expensive, which is highly detrimental to the development of practical AST technology. Furthermore, because optical lever technology uses spatial light to transmit and collect optical signals carrying microcantilever fluctuation information, it leads to severe optical signal loss, and external environmental noise can significantly affect the sensor's accuracy.

[0005] Therefore, the existing demodulation methods for microcantilever nanomechanical biosensors still need to be improved. Summary of the Invention

[0006] The purpose of this application is to provide an optical fiber integrated microcantilever beam nanomechanical biosensor and detection system, which solves the problems of existing microcantilever nanomechanical biosensors, which usually require the use of optical lever technology to accurately read microcantilever fluctuations, and the large size, high cost, and high optical loss of optical lever demodulation technology.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0008] The first aspect of this application provides a fiber-optic integrated microcantilever beam nanomechanical biosensor, comprising:

[0009] Support base;

[0010] An optical fiber includes a cladding and a core, the cladding being disposed on a support, and the core being disposed in the middle of the cladding;

[0011] A microcantilever beam is mounted on a support and located above the cladding. The microcantilever beam has a first end that is aligned with the fiber core of the fiber end face. The microcantilever beam and the fiber form a Fabry-Perot interference structure and are used to generate Fabry-Perot interference with the fiber end face. The distance between the microcantilever beam and the fiber end face is the cavity length of the Fabry-Perot interferometer.

[0012] In one implementation, the support base includes:

[0013] Support beams, which are used to support the cladding;

[0014] The base is mounted on the support beam, and the micro-cantilever beam is mounted on the base.

[0015] In one implementation, the support beam has a through notch or groove in the vertical direction, and the cladding is disposed within the notch or groove.

[0016] In one implementation, the support is a resin base.

[0017] In one implementation, the optical fiber is a single-mode optical fiber.

[0018] In one implementation, the microcantilever beam is a silicon nitride beam.

[0019] A second aspect of this application provides a fiber-optic integrated microcantilever beam nanomechanical biosensor system, the fiber-optic integrated microcantilever beam nanomechanical biosensor system comprising the fiber-optic integrated microcantilever beam nanomechanical biosensor as described above, and the fiber-optic integrated microcantilever beam nanomechanical biosensor system further comprising:

[0020] light source;

[0021] The first end of the coupler is connected to the light source, and the third end of the coupler is connected to the optical fiber of the fiber-integrated microcantilever beam nanomechanical biosensor.

[0022] A spectrometer, which is connected to the second end of a coupler.

[0023] In one implementation, the fiber-optic integrated microcantilever beam nanomechanical biodetection system further includes:

[0024] The flow cell contains the microcantilever beam and the upper end of the optical fiber of the fiber-integrated microcantilever beam nanomechanical biosensor.

[0025] In one implementation, the flow cell is provided with an inlet, and the fiber-optic integrated microcantilever beam nanomechanical biodetection system further includes:

[0026] An injection pump is connected to the injection port via a connecting tube.

[0027] In one implementation, the flow cell is provided with a sample outlet.

[0028] The beneficial effects of the fiber-integrated microcantilever beam nanomechanical biosensor and detection system provided in this application are at least as follows: This application demodulates the cavity length change of the Fabry-Perot interferometer formed by the microcantilever beam and the optical fiber by monitoring the change of the resonant wavelength of the optical fiber interference spectrum, thereby obtaining the up-and-down oscillation signal of the microcantilever beam. This enables the miniaturization of the nanomechanical sensor. Compared with spatial light transmission, using optical fiber as the medium for light transmission and collection can reduce the transmission loss of the optical signal. Furthermore, this application has the advantages of high integration, convenient detection, and low transmission loss. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a fiber-optic integrated microcantilever beam nanomechanical biosensor provided in an embodiment of this application.

[0031] Figure 2 This is a structural diagram illustrating the practical application of a fiber-optic integrated microcantilever beam nanomechanical biosensor provided in this application embodiment.

[0032] Figure 3 The sensor reflectance spectrum measured by a spectrometer at 1260-1615 nm is shown in the actual application of a fiber-optic integrated microcantilever beam nanomechanical biosensor provided in the embodiments of this application.

[0033] Figure 4 In a practical application of a fiber-optic integrated microcantilever nanomechanical biosensor provided in this application, the cantilever deflection curves of Escherichia coli in response to three antibiotics: ampicillin, ceftriaxone, and ciprofloxacin are shown.

[0034] in, Figure 4 A shows the flexural curves of the blank lysate broth solution, the fixed Escherichia coli solution, and the solution treated with 10 μg / ml ciprofloxacin for 30 min, in sequence.

[0035] Figure 4 B shows the bending curves of the cantilever in blank lysate broth, after Escherichia coli fixation, and after treatment with 10 μg / ml ceftriaxone for 30 min, respectively.

[0036] Figure 4 C represents the bending curves of the cantilever in blank lysate broth, after Escherichia coli fixation, and after treatment with 10 μg / ml ampicillin for 30 min, respectively.

[0037] The "M" and "N" lines indicate the time taken to introduce the E. coli solution and antibiotics;

[0038] Figure 4 D is in Figure 4 The variance (change) of cantilever deflection under experimental conditions A;

[0039] Figure 4 E is in Figure 4 The variance of cantilever deflection under experimental conditions B;

[0040] Figure 4 F is in Figure 4 The variance of cantilever deflection under experimental conditions C.

[0041] Figure 5 In a practical application of a fiber-optic integrated microcantilever beam nanomechanical biosensor provided in this application embodiment, the cantilever deflection curves of Escherichia coli in response to different concentrations of ampicillin are shown.

[0042] in, Figure 5 A represents the cantilever flexure curve of the blank lysate broth solution;

[0043] Figure 5 B is in Figure 5 Based on A, the cantilever flexure change curve after E. coli fixation;

[0044] Figure 5 C is in Figure 5 The cantilever flexure curve after treatment with 5 μg / ml ampicillin for 30 min based on B;

[0045] Figure 5 D is in Figure 5 The cantilever flexure curve after treatment with 10 μg / ml ampicillin for 30 min based on B;

[0046] Figure 5 E is in Figure 5The cantilever flexure curve after treatment with 20 μg / ml ampicillin for 30 min based on B;

[0047] Figure 5 F is in Figure 5 The cantilever flexure curve after treatment with 50 μg / ml ampicillin for 30 min based on B;

[0048] Figure 5 G is in Figure 5 The cantilever flexure curve after treatment with 100 μg / ml ampicillin for 30 min based on B;

[0049] Figure 5 H represents the sigmoid curve of the normalized variance versus ampicillin concentration.

[0050] The following are the labeling elements in the figure:

[0051] 1. Support base; 11. Support beam; 111. Notch / groove; 12. Base; 2. Optical fiber; 21. Cladding; 22. Fiber core; 3. Microcantilever beam; 31. First end; 4. Light source; 5. Coupler; 6. Spectrometer; 7. Flow cell; 8. Injection pump. Detailed Implementation

[0052] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0053] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0054] See Figure 1The first aspect of this embodiment provides an optical fiber integrated microcantilever beam nanomechanical biosensor for rapid antibiotic sensitivity testing. The biosensor includes a support 1, an optical fiber 2, and a microcantilever beam 3. The support 1 can be a resin base and is used to support the optical fiber 2 and the microcantilever beam 3. The optical fiber 2 can be a single-mode optical fiber, including a cladding 21 and a core 22. The cladding 21 is disposed on the support 1, and the core 22 is disposed in the middle of the cladding 21. The microcantilever beam 3 uses a material with a low elastic modulus, for example, it can be, but is not limited to, a silicon nitride beam. The silicon nitride beam can have a thickness of 550 nm and an elastic modulus of 0.06. The microcantilever beam 3 is disposed on the support 1 and above the cladding 21. The microcantilever beam 3 has at least a first end 31, which is aligned with the core 22 of the end face of the optical fiber 2.

[0055] The microcantilever beam 3 and optical fiber 2 form a Fabry-Perot interference structure, which is used to generate Fabry-Perot interference with the end face of the optical fiber. The distance between the microcantilever beam 3 and the optical fiber 2 is such that, with the aid of a light source 4, the microcantilever beam 3 and the optical fiber 2 can obtain a reflection spectrum with high interference contrast. The distance between the end face of the microcantilever beam 3 and the optical fiber 2 is the cavity length of the Fabry-Perot interferometer. The distance between the end face of the microcantilever beam 3 and the optical fiber 2 is determined by adjusting the relative distance between the optical fiber 2 and the microcantilever beam 3 under a microscope. (See also...) Figure 1 and Figure 2 The principle of the fiber-integrated microcantilever beam nanomechanical biosensor for detecting antibiotic sensitivity in this embodiment is as follows: Incident light from light source 4 passes through coupler 5 and reaches the core 22 of fiber 2. A portion of the light is emitted from the end face of fiber 2, and the remaining portion exits from the end face and illuminates the lower surface of the microcantilever beam 3, then reflects back into fiber 2. The reflected light from the end face of fiber 2 and the reflected light from the microcantilever beam 3 meet and interfere within fiber 2, propagating in the fiber 2. In this embodiment, bacteria are immobilized on the microcantilever beam 3. The fiber-integrated microcantilever beam 3 nanomechanical biosensor is extremely sensitive to molecules adsorbed on the surface of the microcantilever beam 3, and can convert the in-situ nanoscale movement of bacteria into the movement of the microcantilever beam 3. The slight fluctuations in the microcantilever beam 3 cause changes in the cavity length of the FPI. In this embodiment, the change in the FPI cavity length is detected by monitoring the drift of the interference spectrum resonance wavelength using a spectrometer 6. From the intuitive change in the FPI cavity length, the microscopic fluctuations of the microcantilever beam 3 and the movement of bacteria attached to the microcantilever beam 3 can be obtained. Based on the above, antibiotics are applied to the microcantilever beam 3, and the movement of bacteria will weaken. The degree of weakening is related to the antibiotic concentration. The change in the FPI cavity length is detected again by monitoring the drift of the interference spectrum resonance wavelength. The activity (activity) of bacteria is obtained from the change in the FPI cavity length, thereby completing the antibiotic sensitivity test.

[0056] The specific principle behind detecting the change in FPI cavity length by monitoring the drift of the resonant wavelength in the interference spectrum using spectrometer 6 is as follows: Because the cavity length of the FPI changes with the fluctuation of the microcantilever beam 3, the position of the resonant wavelength in the reflection interference spectrum of fiber 2 changes, and the resonant wavelength change (Δλ) r The relationship between ΔL and cantilever deflection (ΔL) is expressed as Δλ. r / λ r =ΔL / L, where λ r Where is the resonant wavelength, and L is the cavity length of the FPI. The cantilever deflection is the change in the cavity length of the FPI (ΔL). The cavity length of the FPI can be calculated using the following formula:

[0057]

[0058] Where n is the refractive index of the medium in the FPI cavity, which is a known quantity, and the free spectral range (FSR) is the resonant wavelength (λ) between two adjacent interference levels in the sensor's interference spectrum. m and λ m+1 The difference, such as Figure 3 As shown, the cavity length of the FPI is obtained. The resonant wavelength and its variation can be obtained using a spectrometer. Specifically, when reflected light from the fiber end face encounters and interferes within the fiber, propagating through it, the spectrometer receives the interference spectrum and exports the data to a computer for offline processing to obtain the resonant wavelength and its variation. Thus, with the cavity length, resonant wavelength, and variation of the FPI readily available, the cantilever deflection (the cavity length variation of the FPI) can be calculated. It's worth noting that while the spectrometer has a fast sampling speed, sufficient to detect the fluctuations of the microcantilever beam, its low wavelength resolution leads to severe distortion in the received interference spectrum data. This embodiment uses MATLAB to interpolate and fit the collected interference spectrum data to restore the severely distorted data to its true form. Furthermore, by tracking the change in the resonant wavelength of a specific resonant peak, the curve of the resonant wavelength variation versus time is obtained, allowing the calculation of the cantilever deflection variation of the microcantilever beam against time.

[0059] Compared with existing microcantilever nanomechanical biosensors, this application demodulates the cavity length change of the Fabry-Perot interferometer formed by the microcantilever beam 3 and the optical fiber 2 by monitoring the resonant wavelength of the optical fiber interference spectrum, thereby obtaining the up-and-down oscillation signal of the microcantilever beam 3, realizing the miniaturization of the nanomechanical sensor. Moreover, compared with spatial light transmission, using optical fiber as the medium for light transmission and collection can reduce the transmission loss of optical signals. Furthermore, this application has the advantages of high integration, convenient detection, and low transmission loss.

[0060] Before the microcantilever beam is assembled onto the fiber optic end face, it needs to undergo chemical treatment. First, the microcantilever beam is immersed in a piranha solution for 15 minutes to remove contaminants. Then, it is thoroughly rinsed with pure water and air-dried. Next, it is immersed in a 1% glutaraldehyde solution for 15 minutes to increase the surface affinity for bacteria. Finally, it is thoroughly rinsed again with pure water and air-dried. Only after this treatment is the microcantilever beam assembled onto the fiber optic end face.

[0061] See Figure 1 In one embodiment, the support base 1 includes a support beam 11 and a base 12. The cladding layer 21 can be bonded to the support beam 11 by a curing adhesive. The base 12 is disposed on the upper end surface of the support beam 11. The microcantilever beam 3 is disposed on the base 12. The relative distance between the optical fiber 2 and the microcantilever beam 3 is adjusted under a microscope to obtain a suitable cavity length of the Fabry-Perot interferometer in order to obtain an interference spectrum with high contrast. In addition, the position of the microcantilever beam is adjusted under a microscope so that the end 31 of the microcantilever beam is aligned with the fiber core.

[0062] Among them, the curing adhesive can be a UV-curing adhesive.

[0063] See Figure 1 In one embodiment, a notch 111 is provided through the vertical direction of the support beam 11, and the cladding 21 can be bonded to the notch 111 by a curing adhesive. In this embodiment, the notch 111 facilitates the positioning of the optical fiber 2. The curing adhesive is an ultraviolet curing adhesive.

[0064] After the fiber-integrated microcantilever beam nanomechanical biosensor of this embodiment is assembled, in order to facilitate the fixation of bacteria on the microcantilever beam 3, a flow cell 7 is also provided on the support base 1. The flow cell 7 is used to place bacteria or culture medium, etc. Specifically, an installation port (not shown in the figure) is opened at the bottom of the flow cell 7, and the upper end of the support base 1 (including the upper end of the microcantilever beam 3 and the fiber optic 2) is passed through the installation port and extended into the flow cell 7. A curing adhesive is applied to the installation port, and the flow cell 7 is fixedly installed on the support base 1 by the curing adhesive. The installation port is sealed to the support base 1 under the action of the curing adhesive. The curing adhesive can be an ultraviolet light curing adhesive.

[0065] See Figure 2The flow cell 7 is provided with an inlet and an outlet. In this embodiment, the inlet is connected to the injection pump 8 through a connecting tube so that bacteria, culture medium or antibiotics are injected into the flow cell 7 through the injection pump. Similarly, the outlet can be connected to an external container through another connecting tube so that the solution in the flow cell 7 can be discharged through the outlet.

[0066] To verify the effectiveness of the fiber-integrated microcantilever nanomechanical biosensor, this embodiment studied the response of *E. coli* to different antibiotics: First, a lysate solution (bacterial culture medium) was injected into the flow cell 7 using a syringe pump, and the fluctuation of the microcantilever 3 in the blank lysate solution was measured for 5 minutes; then, a solution containing live *E. coli* (1×10⁹ CFU / ml) was injected into the flow cell 7 and incubated for 30 minutes to ensure bacterial attachment to the microcantilever 3. Next, to avoid the original lysate... The effect of bacteria on the broth solution was measured by measuring bacterial activity only at the microcantilever beam 3. A new broth solution without E. coli was injected into the flow cell 7 through the inlet, thereby discharging the old broth solution containing E. coli from the outlet to wash away loosely adhered or floating bacteria. The fluctuation of the microcantilever beam 3 after bacterial attachment was collected and measured for 5 minutes. Finally, a solution containing a specific concentration of antibiotics was injected into the flow cell 7 for antibiotic treatment for 30 minutes, and the fluctuation of the microcantilever beam 3 after antibiotic treatment was recorded for 5 minutes.

[0067] The test concentrations for the three antibiotics, ampicillin, ceftriaxone, and ciprofloxacin, were set at 10 μg / ml. The test results are shown in [reference needed]. Figure 4 The microcantilever beam 3 exhibited very slight fluctuations in blank lysate broth. After *E. coli* attached to the microcantilever beam 3, the fluctuations increased significantly. After incubation with antibiotics for 30 minutes, the fluctuations of the microcantilever beam 3 in the ceftriaxone and ciprofloxacin groups decreased sharply. (See [reference needed]). Figure 4 A and Figure 4 In group B, the fluctuation of microcantilever beam 3 in the ampicillin group decreased slightly. (See reference...) Figure 4 C, the cantilever flexural variance of the ciprofloxacin group, ceftriaxone group, and ampicillin group decreased to 30%, 41%, and 83% of their original values, respectively. (See also...) Figure 4 D and Figure 4 F); It can be concluded that the order of antibiotic sensitivity of Escherichia coli is as follows: ciprofloxacin > ceftriaxone > ampicillin.

[0068] To verify the capability of the fiber-optic integrated microcantilever beam nanomechanical biosensor for quantitative drug sensitivity testing, this embodiment measured the reactions of different concentrations of ampicillin (5 μg / ml, 10 μg / ml, 20 μg / ml, 50 μg / ml, and 100 μg / ml) injected into *E. coli* and lysate broth. Figure 5 As shown, the fluctuations in the 5 μg / ml and 10 μg / ml ampicillin groups were not significant compared to those in lysate broth containing only E. coli; when the ampicillin concentration increased to 20 μg / ml, the fluctuations decreased significantly; and when the ampicillin concentration was 50 μg / ml and 100 μg / ml, the fluctuations in E. coli almost disappeared, indicating that the E. coli were dead. Figure 5 H provides the normalized variance values ​​for each ampicillin concentration, indicating that bacterial nanomove weakens with increasing ampicillin concentration. The relationship between the normalized variance (NV) and ampicillin concentration is fitted using a sigmoid function. MIC and MBC are commonly used to evaluate the ability of antibiotics to resist pathogenic microorganisms. MIC refers to the lowest concentration of antibiotic that inhibits bacterial growth in the culture medium, and MBC refers to the lowest concentration of antibiotic that kills most bacteria in the culture medium. To determine the values ​​of MIC and MBC, the tangent line at the inflection point of the fitted sigmoid curve is first obtained (logEC50 = 16.44). Figure 5 H (dashed line, y = -0.0522c + 1.41), then the x-coordinates of the intersection points of the tangent line and the water line NV(CMIC) = 1 and NV(CMBC) = 0 are calculated as CMIC = 7.9 μg / ml and CMBC = 27.1 μg / ml. The above results verify the rapid detection capability of the fiber-optic integrated microcantilever beam nanomechanical biosensor developed in this application for antimicrobial susceptibility testing (AST).

[0069] like Figure 2 As shown, the second aspect of this embodiment provides a fiber-optic integrated microcantilever beam nanomechanical biosensor system. This system includes the fiber-optic integrated microcantilever beam nanomechanical biosensor described above. It also includes a light source 4, a coupler 5, and a spectrometer 6. The light source 4 can be a broadband light source. The coupler 5 can be a 3dB coupler, which is a bidirectional coupler with four ports: two input ports and two output ports. In this embodiment, the first end 51 of the coupler 5 is connected to the light source 4, and the third end 53 of the coupler 5 is connected to the optical fiber of the fiber-optic integrated microcantilever beam nanomechanical biosensor. The spectrometer 6 can be a near-infrared spectrometer, and it is connected to the second end 52 of the coupler 5.

[0070] In summary, this application provides an optical fiber integrated microcantilever beam nanomechanical biosensor for rapid antibiotic sensitivity testing. It includes a support base 1, an optical fiber 2, and a microcantilever beam 3. The support base 1 can be a resin base and is used to support the optical fiber 2 and the microcantilever beam 3. The optical fiber 2 can be a single-mode optical fiber, including a cladding 21 and a core 22. The cladding 21 is disposed on the support base 1, and the core 22 is disposed in the middle of the cladding 21. The microcantilever beam 3 uses a material with a low elastic modulus; for example, it can be, but is not limited to, a silicon nitride beam. The microcantilever beam 3 is disposed on the support base 1 and above the cladding 21. The microcantilever beam 3 has at least a first end 31, which is connected to the core 2 at the end face of the optical fiber 2. 2. Alignment setup: The microcantilever beam 3 and optical fiber 2 form a Fabry-Perot interference structure, which is used to generate Fabry-Perot interference with the end face of the optical fiber. The distance between the microcantilever beam 3 and optical fiber 2 is the cavity length of the Fabry-Perot interferometer. With the help of the light source 4, the microcantilever beam 3 and optical fiber 2 can obtain a reflection spectrum with high interference contrast. This application demodulates the change in the cavity length of the Fabry-Perot interferometer formed by the microcantilever beam 3 and optical fiber 2 by monitoring the resonant wavelength of the optical fiber interference spectrum, thereby obtaining the up-and-down fluctuation signal of the microcantilever beam 3, realizing the miniaturization of the nanomechanical sensor. Compared with spatial light transmission, using optical fiber as the medium for light transmission and collection can reduce the transmission loss of optical signals. Furthermore, this application has the advantages of high integration, convenient detection, and low transmission loss.

[0071] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fiber-optic integrated microcantilever beam nanomechanical biodetection system, characterized in that, The fiber-optic integrated microcantilever beam nanomechanical biosensor includes a fiber-optic integrated microcantilever beam nanomechanical biosensor, which comprises: Support base; An optical fiber includes a cladding and a core, the cladding being disposed on a support, and the core being disposed in the middle of the cladding; The microcantilever beam is made of a material with a low elastic modulus. The microcantilever beam is a silicon nitride beam, which is set on a support and located above the cladding. The microcantilever beam has a first end, which is aligned with the core of the fiber end face. The microcantilever beam and the fiber form a Fabry-Perot interference structure and are used to generate Fabry-Perot interference with the fiber end face. The distance between the microcantilever beam and the fiber end face is the cavity length of the Fabry-Perot interferometer. The support base includes: Support beams, which are used to support the cladding; A base is mounted on the support beam, and the micro-cantilever beam is mounted on the base; The support beam has a notch or groove extending through it in the vertical direction, and the cladding is disposed within the notch or groove; The support base is also provided with a flow cell. An installation port is opened at the bottom of the flow cell. The micro cantilever beam at the upper end of the support base and the upper end of the optical fiber pass through the installation port and extend into the flow cell. A curing adhesive is applied to the installation port, and the flow cell is fixedly installed on the support base by the curing adhesive. The flow cell is provided with an inlet and an outlet. The fiber-optic integrated microcantilever beam nanomechanical biodetection system also includes: light source; A coupler, the first end of which is connected to a light source, and the third end of which is connected to an optical fiber of an optical fiber integrated microcantilever beam nanomechanical biosensor; The flow cell contains the microcantilever beam and the upper end of the optical fiber of the fiber-integrated microcantilever beam nanomechanical biosensor. The support base is also provided with a flow cell. An installation port is opened at the bottom of the flow cell. The micro cantilever beam at the upper end of the support base and the upper end of the optical fiber pass through the installation port and extend into the flow cell. A curing adhesive is applied to the installation port, and the flow cell is fixedly installed on the support base by the curing adhesive. The flow cell has an inlet, the third end of the coupler is connected to the inlet, and the flow cell has an outlet. A spectrometer, which is connected to the second end of a coupler; An injection pump is connected to the injection port via a connecting tube.

2. The fiber-optic integrated microcantilever beam nanomechanical biodetection system as described in claim 1, characterized in that, The support base is a resin base.

3. The fiber-optic integrated microcantilever beam nanomechanical biodetection system as described in claim 1, characterized in that, The optical fiber is a single-mode optical fiber.

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