A high-sensitivity nano-triangular array near-infrared SPR biosensor

Abstract

The utility model discloses a high sensitivity nanometer triangle array near infrared SPR biosensor, include: including light source module, sensing module, fluid control module and optical signal acquisition module, light source module includes broadband light source, incident multimode optical fiber and first collimating lens, broadband light source one end is connected with incident multimode optical fiber one end, and incident multimode optical fiber other end is connected with first collimating lens, sensing module includes prism and gold nanometer triangle array chip, gold nanometer triangle array chip contains glass sheet, pure gold film and gold nanometer triangle array, and installs flow cell above gold nanometer triangle array chip for the injection and discharge of the sample to be measured, fluid control module includes flow cell and peristaltic pump, the top of flow cell is provided with first liquid port and second liquid port, optical signal acquisition module includes second collimating lens, reflection multimode optical fiber and spectrometer, second collimating lens is connected with reflection multimode optical fiber one end, and reflection multimode optical fiber other end is connected with spectrometer.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology and relates to a high-sensitivity nano-triangular array near-infrared SPR biosensor. Background Technology

[0002] Surface plasmon resonance (SPR) sensing is a highly sensitive detection technique based on optical principles. Its working principle is that when incident light strikes the surface of a prism coated with a thin metal film at a specific angle, total internal reflection occurs, generating an evanescent wave at the metal-dielectric interface. When the wave vector of the evanescent wave matches the collective oscillation of free electrons on the metal surface (i.e., the surface plasmon wave), the SPR effect is excited, leading to a significant attenuation of the reflected light intensity. The SPR effect is highly sensitive to minute changes in the refractive index of the external medium, enabling real-time monitoring of dynamic processes occurring on the sensing surface, such as interactions between biomolecules. Compared to traditional sensing techniques, SPR sensors offer advantages such as strong resistance to electromagnetic interference, high stability, and fast response speed, thus finding wide application in fields such as medical diagnostics, biomolecular interaction analysis, and chemical sensing.

[0003] Currently, traditional SPR sensing technology faces sensitivity limitations when detecting low concentrations of biomolecules, making it impossible for most SPR biosensors to meet the needs of early disease diagnosis. Therefore, developing novel, highly sensitive, label-free SPR sensing technologies is of paramount importance.

[0004] Currently, SPR technology has made significant progress in sensor design, multi-channel detection, portability, and application expansion. However, it still faces many challenges in terms of sensitivity, such as the inability to simultaneously possess the excellent characteristics of high-level volume refractive index sensitivity and surface sensitivity. Therefore, in response to the current technical difficulties, a novel SPR sensor with both high-level volume refractive index sensitivity and surface sensitivity has been invented. Utility Model Content

[0005] To solve the above problems, the technical solution adopted by this utility model is: a high-sensitivity nano-triangular array near-infrared SPR biosensor, comprising: a light source module, a sensing module, a fluid control module, and a light signal acquisition module; The light source module includes a broadband light source, an incident multimode fiber, and a first collimating lens; One end of the broadband light source is connected to one end of the incident multimode fiber, and the other end of the incident multimode fiber is connected to the first collimating lens. The sensing module includes a prism and a gold nanoparticle delta array chip; The gold nano-triangular array chip comprises K9 glass, a pure gold film, and a gold nano-triangular array. A pure gold film is deposited on the surface of a K9 glass slide; a gold nano-triangular array is formed on the surface of the pure gold film. A gold nanoparticle triangular array chip is placed above a prism, and a flow cell is installed above the gold nanoparticle triangular array chip for the injection and discharge of the sample to be tested. The fluid control module includes a flow tank and a peristaltic pump; A first liquid inlet and a second liquid inlet are provided above the flow cell; The sample to be tested is injected into the flow cell through the first liquid port by a peristaltic pump, flows over the surface of the gold nano-triangular array chip, and is discharged from the second liquid port; The optical signal acquisition module includes a second collimating lens, a reflective multimode fiber, and a spectrometer; The second collimating lens is connected to one end of the reflecting multimode fiber; The other end of the reflective multimode fiber is connected to the spectrometer; The prism is positioned between the first collimating lens and the second collimating lens.

[0006] Furthermore, the prism is an isosceles trapezoidal K9 glass with an upper apex angle of 26.06° and a lower apex angle of 153.94°.

[0007] Furthermore, it also includes a first fiber optic connector, a second fiber optic connector, a third fiber optic connector, and a fourth fiber optic connector; One end of the incident multimode fiber is connected to a first fiber optic connector, and the other end of the incident multimode fiber is connected to a second fiber optic connector. One end of the incident multimode fiber is connected to a third fiber optic connector, and the other end of the incident multimode fiber is connected to a fourth fiber optic connector.

[0008] Furthermore: the first fiber optic connector, the second fiber optic connector, and the third fiber optic connector are of model SMA905; The fourth fiber optic connector is an FC / APC connector.

[0009] Furthermore, a hexagonal close-packed structure is formed on the surface of the pure gold film.

[0010] Furthermore, the thickness of the pure gold film is 50 nm.

[0011] Furthermore, the incident angle of the broadband light source is 62.34°.

[0012] According to a high-sensitivity nanotriangular array near-infrared SPR biosensor, the following are included: Nano-triangular array near-infrared SPR biosensing region: used to excite a highly sensitive SPR effect and dynamically acquire information on changes in reflected light intensity caused by sample changes; Spectrometer: Used to detect and analyze the light information transmitted by the nano-triangular array near-infrared SPR biosensor; Computer: Used to process and display the spectral data transmitted by the spectrometer.

[0013] This invention provides a high-sensitivity nano-triangular array near-infrared SPR biosensor. A high-sensitivity SPR biochemical sensing chip was designed and fabricated, and a near-infrared SPR sensing platform was successfully used to monitor the specific binding processes of various ultra-low concentrations of biomolecules. This overcomes the technical challenges faced by traditional SPR sensors in detecting low concentrations of biomolecules.

[0014] This paper analyzes and develops a near-infrared SPR sensing system using a nano-triangular array. By designing and fabricating a gold nano-triangular array sensing chip, the surface refractive index sensitivity is significantly improved through near-field hotspot excitation. Furthermore, by setting a small excitation angle for the SPR effect, efficient SPR excitation in the near-infrared band is successfully achieved, thereby greatly enhancing the volume refractive index sensitivity. This sensing system possesses both ultra-high volume refractive index sensitivity and surface sensitivity. This technology enables highly sensitive detection of samples with minute concentrations and small molecules, demonstrating broad application prospects in the field of biochemical detection. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 Diagram of the SPR detection system; Figure 2 A schematic diagram of a prism-type sensing element; Figure 3 The three views are of the gold nano-triangular array sensor chip, including (a) top view, (b) left view, and (c) front view. Reference numerals: 1. Prism; 2. Gold nanoparticle triangular array chip; 3. Sample to be tested; 4. Incident light; 5. Outgoing light; 6. Light source incident angle; 7. First liquid port; 8. Second liquid port; 9. Flow cell; 10. Peristaltic pump; 11. Broadband light source; 12. First collimating lens; 13. Spectrometer; 14. Computer; 15. First fiber optic connector; 16. Incident multimode fiber; 17. Second fiber optic connector; 18. Reflecting multimode fiber; 19. USB data cable; 20. Gold nanoparticle triangular array; 21. Pure gold film; 22. K9 glass plate; 23. Peristaltic pump tubing; 24. Spatial optical path; 25. Air incident angle; 26. Glass reflection angle; 27. Third fiber optic connector; 28. Fourth fiber optic connector; 29. ​​Second collimating lens. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Figure 1 Diagram of the SPR detection system; Figure 2 A schematic diagram of a prism-type sensing element; A high-sensitivity nanotriangular array near-infrared SPR biosensor, comprising: Light source module, sensing module, fluid control module, and optical signal acquisition module; The light source module includes a broadband light source 11, an incident multimode fiber 16, and a first collimating lens 12. One end of the broadband light source 11 is connected to one end of the incident multimode fiber 16, and the other end of the incident multimode fiber 16 is connected to the first collimating lens 12. The sensing module includes a prism 1 and a gold nanoparticle triangular array chip 2; In this process, a gold nano-triangular array chip 2 is placed above a prism 1, and a flow cell 9 is installed above the gold nano-triangular array chip 2 for the injection and discharge of the sample to be tested. The substrate of the gold nano-triangular array chip 2 is a K9 glass plate 22, and a pure gold film 21 is disposed on the surface. The pure gold film 21 is used to excite SPR. A gold nano-triangular array 20 is disposed on the surface of the pure gold film 21. The function of the gold nano-triangular array 20 is to excite the near-field hot spot effect to achieve a significant increase in surface refractive index sensitivity. The fluid control module includes a flow tank 9 and a peristaltic pump 10; The flow cell 9 is provided with a first liquid outlet 7 and a second liquid outlet 8 above it; The sample to be tested is injected into the flow cell 9 by the peristaltic pump 10 through the peristaltic pump hose 23 via the first liquid port 7, flows over the surface of the gold nano-triangular array chip 2, and is discharged from the second liquid port 8; thus realizing the dynamic detection of the sample. The optical signal acquisition module includes a second collimating lens 29, a reflective multimode fiber 18, and a spectrometer 13; The second collimating lens 29 is connected to one end of the reflecting multimode fiber 18; The other end of the reflective multimode fiber 18 is connected to the spectrometer 13; The prism 1 is positioned between the first collimating lens 12 and the second collimating lens 29.

[0020] The incident light 4 emitted by the broadband light source 11 is transmitted through the incident multimode fiber 16. After being collimated and expanded by the first collimating lens 12, it forms an air incident angle 25 in the spatial optical path 24 and irradiates the surface of the prism 1. An effect is excited at the interface between the gold nano-triangular array chip 2 and the sample 3 under test, forming a glass reflection angle 26, which causes a significant attenuation of the reflected light intensity. The outgoing light 5 carrying the sample information is focused by the second collimating lens 29 and transmitted through the reflecting multimode fiber 18.

[0021] The prism 1 is an isosceles trapezoidal K9 glass with an upper apex angle of 26.06° and a lower apex angle of 153.94°.

[0022] The sensing area also includes a first fiber optic connector 15, a second fiber optic connector 17, a third fiber optic connector 27, and a fourth fiber optic connector 28. One end of the incident multimode fiber 16 is connected to the first fiber connector 15, and the other end of the incident multimode fiber 16 is connected to the second fiber connector 17. One end of the incident multimode fiber is connected to the third fiber connector 27, and the other end of the incident multimode fiber 16 is connected to the fourth fiber connector 28.

[0023] The first fiber optic connector 15, the second fiber optic connector 17, and the third fiber optic connector 27 are of model SMA905. The fourth fiber optic connector 28 is an FC / APC connector.

[0024] The thickness of the pure gold film 21 is 50 nm.

[0025] Figure 3 The three views of the gold nano-triangular array sensor chip are: (a) top view, (b) left view, and (c) front view. The fabrication process of the gold nano-triangular array chip 2 is as follows: Vacuum thermal evaporation deposition technology is used, employing polystyrene (PS) microspheres as a mask to prepare the surface of the nano-triangular array sensing structure. A large-area self-assembly of a single-layer hexagonal tightly packed pattern is then completed on the K9 glass slide 22 using the Langmuir-Blodgett process. The Langmuir-Blodgett process, also known as the LB film technology, is a precision technique for preparing single-layer or multi-layer ultrathin films, widely used in materials science, nanotechnology, and surface chemistry.

[0026] The self-assembly process of the PS ball is described as follows: (1) Mix a 2.5 wt.% PS microsphere dispersion with an equal volume of ethanol solution and sonicate for 20 minutes to ensure that the PS microspheres are uniformly dispersed in the mixed solution; (2) Add deionized water to the petri dish and place a tilted K9 glass slide at its edge. Use a pipette to drop 10 μL of the PS microsphere ethanol mixture onto the tilted K9 glass slide, allowing it to slide down naturally and spread rapidly on the water surface; (3) Add a 1% sodium dodecyl sulfate solution to the petri dish to promote the rapid aggregation and self-assembly of PS microspheres to form a monolayer. Let it stand for 30 minutes to allow it to reach a better thermodynamic equilibrium and form a hexagonal close-packed structure; (4) The K9 glass slide (2 cm × 2 cm) was ultrasonically cleaned in sequence with acetone, ethanol and deionized water; (5) Immerse the cleaned K9 glass slide in piranha washing solution (prepared by mixing H2O2 and H2SO4 in a volume ratio of 3:7) to enhance the hydrophilicity of the K9 glass slide surface; (6) Rinse the K9 glass slide with deionized water and blow dry the surface with high-purity nitrogen to ensure that the substrate is clean and dry; (7) Using the K9 glass slide, the PS monolayer film after resting in step (3) is lifted, and a hexagonal tightly filled pattern is attached to the K9 glass slide, and allowed to evaporate until dry. Based on the above steps, PS microspheres can self-assemble into a monolayer film hexagonal tightly filled pattern on the K9 glass slide.

[0027] The fabrication process of the gold nanotriangle array 20 sensing structure is as follows: A 50 nm thick gold film is deposited on the surface of a pre-prepared PS microsphere monolayer using thermal evaporation. The sensing chip after gold film deposition is placed in a 95% ethanol solution and sonicated for 5 minutes to remove the PS microsphere mask. Due to the approximately vertical deposition of the gold film during thermal evaporation, the gold film is deposited only in the gaps between the PS microspheres. Therefore, after removing the PS microspheres, a uniformly distributed circular void structure is formed on the surface, thus constructing an approximate nanotriangle array. Finally, another 50 nm gold film is deposited on its surface, ultimately fabricating a continuous gold nanotriangle array 20 sensing structure on a K9 glass slide.

[0028] The system according to the aforementioned high-sensitivity nanotriangular array near-infrared SPR biosensor includes: The nano-triangular array near-infrared SPR biosensing region is used to excite a highly sensitive SPR effect and dynamically acquire information on significant changes in reflected light intensity caused by sample variations. SPR stands for Surface Plasmon Resonance. Surface plasmon resonance is an optical phenomenon where light energy is absorbed or scattered when incident light (usually polarized light) resonates with free electrons on the surface of a metal (such as gold or silver) nanostructure, resulting in a significant change in reflected light intensity. Computer 14: Used to display, analyze and process the spectral data transmitted by the spectrometer 13, acquire the center wavelength of the SPR spectrum, and draw data graphs.

[0029] A high-sensitivity nano-triangular array near-infrared SPR biosensor was designed and constructed. The specific implementation scheme of the sensor is as follows: A broadband light source 11 is turned on, and incident light 4 enters the incident multimode fiber 16 through the first fiber optic connector 15, then is transmitted to the first collimating lens 12, which converts the beam into parallel light with a larger diameter. A peristaltic pump 10 pumps the sample 3 into the flow cell 9. The parallel light source incident at an angle 6 of 62.34° illuminates the surface of the trapezoidal prism 1, exciting the SPR effect at the interface between the gold nano-triangular array chip 2 and the sample 3, generating outgoing light 5. Outgoing light 5 carries SPR refractive index information, is focused by the second collimating lens 29, enters the reflective multimode fiber 18, and is finally transmitted to the spectrometer 13 via the fourth fiber optic connector 28. The spectrometer 13 transmits the detection data to the computer 14 via a USB data cable 19 for subsequent data display and processing.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-sensitivity nanotriangular array near-infrared SPR biosensor, characterized in that: include: Light source module, sensing module, fluid control module, and optical signal acquisition module; The light source module includes a broadband light source, an incident multimode fiber, and a first collimating lens; One end of the broadband light source is connected to one end of the incident multimode fiber, and the other end of the incident multimode fiber is connected to the first collimating lens. The sensing module includes a prism and a gold nanoparticle delta array chip; The gold nano-triangular array chip comprises a K9 glass sheet, a pure gold film, and a gold nano-triangular array. A pure gold film is deposited on the surface of a K9 glass slide; a gold nano-triangular array is formed on the surface of the pure gold film. A gold nanoparticle triangular array chip is placed above a prism, and a flow cell is installed above the gold nanoparticle triangular array chip for the injection and discharge of the sample to be tested. The fluid control module includes a flow tank and a peristaltic pump; The flow cell is provided with a first liquid outlet and a second liquid outlet above it; The sample to be tested is injected into the flow cell through the first liquid port by a peristaltic pump, flows over the surface of the gold nano-triangular array chip, and is discharged from the second liquid port; The optical signal acquisition module includes a second collimating lens, a reflective multimode fiber, and a spectrometer; The second collimating lens is connected to one end of the reflecting multimode fiber; The other end of the reflective multimode fiber is connected to the spectrometer; The prism is positioned between the first collimating lens and the second collimating lens.

2. The high-sensitivity nanotriangular array near-infrared SPR biosensor according to claim 1, characterized in that: The prism is an isosceles trapezoidal K9 glass with an upper apex angle of 26.06° and a lower apex angle of 153.94°.

3. The high-sensitivity nanotriangular array near-infrared SPR biosensor according to claim 1, characterized in that: It also includes a first fiber optic connector, a second fiber optic connector, a third fiber optic connector, and a fourth fiber optic connector; One end of the incident multimode fiber is connected to a first fiber optic connector, and the other end of the incident multimode fiber is connected to a second fiber optic connector. One end of the incident multimode fiber is connected to a third fiber optic connector, and the other end of the incident multimode fiber is connected to a fourth fiber optic connector.

4. The high-sensitivity nanotriangular array near-infrared SPR biosensor according to claim 3, characterized in that: The first, second, and third fiber optic connectors are all of model SMA905. The fourth fiber optic connector is an FC / APC connector.

5. A high-sensitivity nanotriangular array near-infrared SPR biosensor according to claim 1, characterized in that: The incident angle of the broadband light source is 62.34°.

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