Pear-shaped optical fiber, pear-shaped optical fiber LSPR and monitoring device

Abstract

The utility model relates to the field of optical detection, in particular to a pear-shaped optical fiber, a pear-shaped optical fiber LSPR (Localized Surface Plasmon Resonance) and a monitoring device. The pear-shaped optical fiber LSPR is formed by processing a multimode optical fiber and comprises a pear-shaped structure and an optical fiber structure, the optical fiber structure is connected with the pear-shaped structure, and the maximum outer diameter of the pear-shaped structure is 0.4 mm-0. 9mm. The optical fiber LSPR disclosed by the utility model can be used for rapidly acquiring the weak change of the refractive index along with the blood coagulation process of human serum and obtaining a PT result within 1 minute. The monitoring method has the advantages that the device is portable, the operation is simple, the analysis is rapid, the household PT monitoring is expected to be realized, and a potential solution is provided for the household self-management of the anticoagulant medicine of the atrial fibrillation patient.

Description

Technical Field

[0001] This utility model relates to the field of optical detection, specifically to a pear-shaped optical fiber, a pear-shaped optical fiber LSPR, and a monitoring device. Background Technology

[0002] In recent years, fiber optic LSPR biosensors have attracted widespread attention and have been applied in fields such as biomedicine, drug screening, food safety, and environmental monitoring. However, the low sensitivity of traditional fiber optic LSPR sensors has limited their further applications. Therefore, many researchers have explored the modification of fiber surfaces with nanomaterials to enhance refractive index sensitivity and improve detection accuracy by improving LSPR excitation. However, the improvement in refractive index sensitivity achieved by improving the properties of the modifiers is very limited. Therefore, researchers have focused on the inherent characteristics of the fiber itself, investigating how changing the fiber shape can significantly improve the refractive index sensitivity of fiber optic sensors. In other words, the sensitivity of fiber optic LSPR sensors is greatly influenced by the inherent properties of the fiber.

[0003] However, the sensitivity of bare optical fibers can hardly exceed 30 (au) / RIU. Based on this, even with the modification of nanomaterials, the improvement in sensitivity is limited. Furthermore, excessive modification with nanomaterials can lead to spectral confusion due to limitations in the precision of the spectrometer, ultimately resulting in inaccurate monitoring results. This places even higher demands on the precision of the spectrometer and increases the cost of monitoring.

[0004] Furthermore, currently, whether it is changing the shape, optimizing the modification of nanomaterials, or combining both to improve the refractive index sensitivity of fiber LSPR, it is impossible to monitor very weak refractive index changes, which limits the application of fiber LSPR. Utility Model Content

[0005] To address the issue of low refractive index sensitivity leading to excessively high requirements for monitoring equipment, this invention proposes a novel pear-shaped optical fiber. By miniaturizing the overall structure of the fiber, the refractive index sensitivity of the optical fiber sensor is significantly improved, ultimately enabling the detection of minute refractive index changes using simple monitoring equipment. Details are as follows:

[0006] A pear-shaped optical fiber, formed by processing multimode optical fiber, comprising a pear-shaped structure and an optical fiber structure, wherein the optical fiber structure is connected to the pear-shaped structure, and the maximum outer diameter of the pear-shaped structure is 0.4 mm - 0.9 mm.

[0007] Furthermore, the maximum outer diameter of the pear-shaped structure is 0.4 mm - 0.7 mm.

[0008] The pear-shaped structure includes a first straight segment, a first curved segment, and a second straight segment. The two ends of the first curved segment are connected to the first straight segment and the second straight segment, respectively. There is an angle between the first straight segment or the second straight segment and the first curved segment; or there is an angle between the first straight segment and the second straight segment.

[0009] In some embodiments, there is an angle between the first straight segment or the second straight segment and the first curved segment, and at the same time, there is an angle between the first straight segment and the second straight segment;

[0010] In some embodiments, there is an angle between the first straight segment or the second straight segment and the first curved segment, while there is no angle between the first straight segment and the second straight segment;

[0011] In some embodiments, there is no included angle between the first straight segment or the second straight segment and the first curved segment, while there is an included angle between the first straight segment and the second straight segment.

[0012] The “first straight segment” and “second straight segment” mentioned in this utility model refer to straight segments or near-straight segments, which are straight segments in appearance relative to curved segments, but may have slight bends.

[0013] The first straight section, the first curved section, and the second straight section described in this utility model are artificially divided; in actual firing, they are formed as a single piece.

[0014] The "maximum outer diameter of the pear-shaped structure" mentioned in this utility model refers to the value of the position with the maximum width in the pear-shaped structure, which is the maximum outer diameter of the first curved segment mentioned above. The outer diameter refers to the diameter including the core and cladding, while the maximum outer diameter refers to the maximum diameter of the entire pear-shaped structure including the core and cladding.

[0015] Furthermore, the total height of the pear-shaped structure is 1 mm - 5 cm, and the total height is the vertical distance from the endpoint of the first straight segment and the second straight segment away from the first curved segment to the farthest point of the first curved segment. Preferably, the total height of the pear-shaped structure is 1 mm - 1 cm.

[0016] Furthermore, the pear-shaped structure is composed of a SiO2 core and a SiO2 cladding; the optical fiber structure is composed of a SiO2 core, a SiO2 cladding, and a coating layer.

[0017] Furthermore, the diameter of the SiO2 core is 50 or 62.5 μm, and the diameter of the SiO2 cladding is 125 μm.

[0018] On the other hand, this utility model discloses a pear-shaped optical fiber LSPR, wherein the pear-shaped optical fiber LSPR contains the aforementioned pear-shaped optical fiber.

[0019] Furthermore, the pear-shaped structure of the pear-shaped optical fiber LSPR includes a SiO2 core, a SiO2 cladding, and a nano-metal material. The SiO2 cladding wraps around the outer layer of the SiO2 core, and the nano-metal material modifies the SiO2 cladding.

[0020] Furthermore, the nanomaterial is selected from gold nanoparticles or silver nanoparticles. Preferably, the nanomaterial is selected from gold nanoparticles. More preferably, the gold nanoparticles are selected from gold nanospheres, gold nanorods, or gold nanostars.

[0021] On the other hand, this utility model discloses a monitoring device, which includes a light source, a detector, an output device, a pear-shaped optical fiber LSPR, and an optical fiber patch cord. The pear-shaped optical fiber LSPR is connected to one end of the light source and one end of the detector through the optical fiber patch cord, and the other end of the detector is connected to the output device through the optical fiber patch cord.

[0022] In actual monitoring, a beam of light of continuous wavelength emitted from the light source propagates along the fiber optic jumper to the fiber optic probe. The light undergoes localized surface plasmon resonance at the probe covered with spherical gold nanoparticles, and the wavelength and intensity of the resonance absorption peak change. After the optical signal is processed by a spectrometer, spectral data analysis is performed on the computer. Beneficial effects

[0023] (1) This utility model utilizes extremely fine optical fibers to control the maximum outer diameter of the pear-shaped structure to 0.3 mm - 1 mm, which can greatly improve the refractive index sensitivity. Since the pear-shaped structure is the detection part of the pear-shaped optical fiber, the miniaturized structure can reduce the amount of sample and related reagents used.

[0024] (2) Modifying metal nanomaterials on the basis of pear-shaped optical fiber further enhances the refractive index sensitivity, enabling the detection of weak refractive index changes and meeting the monitoring requirements of conventional spectrometers. Because the pear-shaped optical fiber LSPR itself has ultra-high sensitivity, it is more compatible with equipment and can be applied to more detection scenarios. Attached Figure Description

[0025] Figure 1 A schematic diagram of a pear-shaped fiber LSPR structure;

[0026] Figure 2 This is a schematic diagram of an optical fiber structure;

[0027] Figure 3 A schematic diagram of a pear-shaped structure;

[0028] Figure 4 The monitoring spectra of a 0.65 mm pear-shaped optical fiber in sucrose solutions of different concentrations. Detailed Implementation

[0029] The following embodiments are intended to illustrate the above-described utility model and should not be construed as limiting its scope. Those skilled in the art will readily recognize that the embodiments present many other ways in which the present utility model can be implemented. It should be understood that many variations and modifications can be made while remaining within the scope of the present utility model.

[0030] 1-Fiber optic structure, 2-Pear-shaped structure, 3-Metallic nanomaterials Example

[0031] A monitoring device includes a light source, a detector, an output device, a pear-shaped optical fiber / pear-shaped optical fiber LSPR, and an optical fiber patch cord. The pear-shaped optical fiber / pear-shaped optical fiber LSPR is connected to one end of the light source and one end of the detector respectively through the optical fiber patch cord. The other end of the detector is connected to the output device through the optical fiber patch cord to output a real-time monitoring signal.

[0032] In this embodiment, the light source is a THORLABS SLS201 / M with a light energy of 10 mWh - 100 mWh.

[0033] Spectrometer (Avantes AvaSpac-ULS2048)

[0034] like Figure 1 As shown, a pear-shaped optical fiber 1 is made of multimode optical fiber and includes a pear-shaped structure 1 and an optical fiber structure 1. The optical fiber structure 1 is connected to the pear-shaped structure 2. The maximum outer diameter of the pear-shaped structure 1 is 0.3 mm - 1 mm.

[0035] In some embodiments, the maximum outer diameter of the pear-shaped structure 1 is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0036] Pear-shaped optical fiber 1 is formed by processing multimode optical fiber, such as Figure 2 The multimode optical fiber consists of a SiO2 core 11, a SiO2 cladding 12, and a coating layer 13, with the coating layer 13 sequentially wrapping the cladding 12 and the core 11.

[0037] The pear-shaped structure 2 is composed of a SiO2 core 11 and a SiO2 cladding 12; the optical fiber structure 1 is composed of a SiO2 core 11, a SiO2 cladding 12 and a coating layer 13.

[0038] That is, the pear-shaped optical fiber 1 is made by burning multimode optical fiber and removing the coating layer 13.

[0039] In addition, such as Figure 3As shown, the pear-shaped structure 2 includes a first straight segment 21, a first curved segment 22, and a second straight segment 23. The two ends of the first curved segment 22 are connected to the first straight segment 21 and the second straight segment 22, respectively. There is an angle α between the first straight segment 21 or the second straight segment 23 and the first curved segment 22; or there is an angle β between the first straight segment 21 and the second straight segment 23.

[0040] In this embodiment, there is an angle α between the first straight segment 21 or the second straight segment 23 and the first curved segment 22, and at the same time, there is an angle β between the first straight segment 21 and the second straight segment 23;

[0041] In some embodiments, there is an angle α between the first straight segment 21 or the second straight segment 23 and the first curved segment 22, while there is no angle between the first straight segment 21 and the second straight segment 23;

[0042] In some embodiments, there is no included angle between the first straight segment 21 or the second straight segment 23 and the first curved segment 22, while there is an included angle between the first straight segment 21 and the second straight segment 23.

[0043] Furthermore, the total height h of the pear-shaped structure 2 is 1 mm - 5 cm. The total height is the vertical distance from the endpoint of the first straight segment 21 and the second straight segment 23 away from the first curved segment 22 at the farthest point. Preferably, the total height of the pear-shaped structure 2 is 1 mm - 10 mm.

[0044] In specific embodiments, the total height of the pear-shaped structure 2 is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, or 50 mm.

[0045] The smaller the height, the less solution needs to be immersed during monitoring, which can save costs.

[0046] The diameter of the SiO2 core 11 is 50 or 62.5 μm, and the diameter of the SiO2 cladding 12 is 125 μm.

[0047] The main reason this invention can construct a miniaturized fiber optic sensor is due to the small diameter of the SiO2 core and SiO2 cladding. The optical fiber used is a common communication fiber available on the market, which is inexpensive and readily available.

[0048] Preparation of pear-shaped optical fiber: Take 62.5μm / 125μm multimode optical fiber (commercially available communication optical fiber) and remove part of the plastic outer layer; use wire strippers to strip 2 mm - 10 cm of the plastic coating layer. Place the part with the plastic outer layer removed on a butane flame and heat it into a pear shape in one step under external force.

[0049] Pear-shaped optical fibers with a maximum outer diameter of 0.65 mm were sintered.

[0050] Refractive index sensitivity detection: The fiber optic probe is placed in sucrose solutions with different refractive indices, the fiber absorption spectrum is recorded, and the refractive index sensitivity is calculated.

[0051] Detection spectrum as shown Figure 4 As shown, the detection was repeated 6 times, and the average refractive index sensitivity was calculated to be 42.12 (au) / RIU.

[0052] Furthermore, in this embodiment, various maximum outer diameters were fired: 1.1 mm, 1 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, and 0.4 mm. The average refractive index sensitivity values ​​were measured and calculated using the method described above, and were as follows:

[0053] It can be seen that when the maximum outer diameter of the pear-shaped fiber is 0.4-0.9 mm, the refractive index sensitivity is greater than 20 au / RIU, which is relatively high. On this basis, further modification with metal nanoparticles can achieve twice the result with half the effort, enabling the common detection experiments of fiber LSPR. When the maximum outer diameter of the pear-shaped fiber is 0.4-0.7 mm, the refractive index sensitivity is higher than 30 a.u. / RIU, which can be used for high-precision monitoring. When the maximum outer diameter of the pear-shaped fiber is 0.4-0.5 mm, it can detect very small changes in refractive index, such as the process of blood coagulation. Example

[0054] Based on Example 1, the pear-shaped optical fiber can be modified by selecting a nano-metal material, which can be selected from nano-gold or nano-silver. Preferably, the nano-metal material is selected from nano-gold, and more preferably, the nano-gold is selected from gold nanospheres, gold nanorods, or gold nanostars.

[0055] Nanomaterials can induce the LSPR phenomenon, enhance the detection signal, and further improve the sensitivity of fiber optic sensors, thereby enabling real-time monitoring of even minute changes in refractive index.

[0056] In this embodiment, gold nanospheres are selected, such as... Figure 1 As shown, the pear-shaped structure 2 of the pear-shaped fiber LSPR includes a SiO2 core 11, a SiO2 cladding 12, and a nano-metal material 3. The SiO2 cladding 12 wraps around the outer layer of the SiO2 core 11, and the nano-metal material 3 is modified on the SiO2 cladding 12.

[0057] The nanomaterial 3 can be uniformly modified on the entire surface of the pear-shaped structure 2, or it can be non-uniformly modified. It can partially cover the pear-shaped structure 2 or completely cover the pear-shaped structure 2, depending on the signal amplification that needs to be enhanced.

[0058] The uniform modification refers to the uniform arrangement of nanomaterials on the surface of the pear-shaped structure in the region modified with nanomaterials.

[0059] The term "partially covered" means that the area modified by the nanomaterial is one or more segments of the pear-shaped structure 2. It can be one or more segments of the first curved segment, the first straight segment, or the second straight segment, or it can be a small segment or more small segments of the first curved segment, the first straight segment, or the second straight segment. It can be a continuous or interrupted modification. The appropriate modification method can be selected according to the required enhancement level.

[0060] Preferably, for ease of operation, the modification is carried out by immersion in the pear-shaped structure, continuously and uniformly covering the entire surface of the pear-shaped structure with nano-metallic materials.

[0061] In actual monitoring, a beam of light of continuous wavelength emitted from the light source propagates along the fiber optic jumper to the fiber optic probe. The light undergoes localized surface plasmon resonance at the probe covered with spherical gold nanoparticles, and the wavelength and intensity of the resonance absorption peak change. After the optical signal is processed by a spectrometer, spectral data analysis is performed on the computer.

[0062] Fabrication of pear-shaped fiber LSPR: Since modification with nanomaterials can improve refractive index sensitivity, this embodiment uses only the maximum outer diameter of one type of pear-shaped structure as an example. The pear-shaped fiber with a maximum outer diameter of 0.65 mm from Example 1 is selected.

[0063] (1) Functionalization of pear-shaped optical fiber: The pear-shaped structure was soaked in aqua regia for 20 minutes to clean its surface impurities, then the optical fiber was washed with ultrapure water, ultrasonicated with ultrapure water for 5 minutes, and dried in a dryer at 60˚C.

[0064] (2) First, take 1.5 ml of 30% H2O2 melt into a small beaker, then take 3.5 ml of concentrated sulfuric acid into a small beaker to prepare piranha melt. Then, put the dried optical fiber into the piranha melt and react at 90 ˚C for 30 minutes.

[0065] (3) After the reaction is complete, pour the piranha waste liquid into the waste liquid bucket (acid), rinse the beaker and the pear-shaped structure with ultrapure water, and sonicate with ultrapure water for 5 minutes.

[0066] (4) After ultrasonic treatment, dry at 50˚C for 10 minutes. Prepare a 5% APTMS solution with 2 ml glacial acetic acid, 5 ml ethanol and 350 μl APTMS, and place the optical fiber in the reaction for 30 minutes. After the reaction, rinse three times with ultrapure water. Then ultrasonicate with ultrapure water for 10 minutes, then ultrasonicate with anhydrous ethanol for 5 minutes, and finally dry at 60˚C for later use.

[0067] The surface of the pear-shaped structure is aminated to give it a positive charge. The synthesized gold nanoparticles, encapsulated with citrate ions, readily adhere to the pear-shaped structure surface via electrostatic adsorption, thus facilitating the fabrication of pear-shaped optical fiber LSPR.

[0068] (5) Modification of the surface of the pear-shaped structure with nano-gold

[0069] Synthesized gold nanospheres (13 nm) were co-incubated with aminated optical fibers. A detection device monitored changes in the absorption spectrum in real time. The LSPR peak of the absorption spectrum was selected as the sensor signal. Seven fiber probes with LSPR peak values ​​of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 au were prepared from pear-shaped optical fibers. The pear-shaped fiber LSPR was placed in sucrose solutions with different refractive indices, and the fiber absorption spectra were recorded. The average refractive index sensitivity was calculated based on six measurements.

[0070] The results are as follows:

[0071] It can be seen that the refractive index sensitivity is significantly improved with the modification of gold nanospheres, opening up possibilities for its further applications.

[0072] Because of the ultra-high sensitivity of pear-shaped fiber LSPR, it is more compatible with various equipment and can be applied to more detection scenarios.

[0073] While specific embodiments have been described above with reference to disclosed examples and embodiments, such embodiments are merely illustrative and do not limit the scope of the present invention. Changes and modifications can be made by those skilled in the art without departing from the broader aspects of the present invention as defined in the appended claims.

Claims

1. A pear-shaped optical fiber, characterized in that, The pear-shaped optical fiber consists of a pear-shaped structure and an optical fiber structure, with the optical fiber structure connected to the pear-shaped structure. The maximum outer diameter of the pear-shaped structure is 0.4 mm - 0.9 mm.

2. The pear-shaped optical fiber as described in claim 1, characterized in that... The maximum outer diameter of the pear-shaped structure is 0.4 mm - 0.7 mm.

3. The pear-shaped optical fiber as described in claim 1 or 2, characterized in that, The pear-shaped structure includes a first straight segment, a first curved segment, and a second straight segment. The two ends of the first curved segment are connected to the first straight segment and the second straight segment, respectively. There is an angle between the first straight segment or the second straight segment and the first curved segment; or there is an angle between the first straight segment and the second straight segment.

4. The pear-shaped optical fiber as described in claim 3, characterized in that, The total height of the pear-shaped structure is 1 mm - 5 cm. The total height is the vertical distance between the endpoints of the first straight segment and the second straight segment that are furthest from the first curved segment.

5. The pear-shaped optical fiber as described in claim 1, 2, or 4, characterized in that, The pear-shaped optical fiber is formed by processing multimode optical fiber, and the pear-shaped structure is composed of a SiO2 core and a SiO2 cladding; the optical fiber structure is composed of a SiO2 core, a SiO2 cladding, and a coating layer.

6. The pear-shaped optical fiber as described in claim 5, characterized in that, The diameter of the SiO2 core is 50 or 62.5 μm, and the diameter of the SiO2 cladding is 125 μm.

7. A pear-shaped optical fiber LSPR, characterized in that, The pear-shaped fiber LSPR contains the pear-shaped fiber as described in any one of claims 1-6.

8. The pear-shaped optical fiber LSPR as described in claim 7, characterized in that, The pear-shaped fiber LSPR has a pear-shaped structure comprising a SiO2 core, a SiO2 cladding, and a nanomaterial. The SiO2 cladding wraps around the outer layer of the SiO2 core, and the nanomaterial modifies the SiO2 cladding.

9. The pear-shaped optical fiber LSPR as described in claim 8, characterized in that, The nanomaterials are selected from nano-gold or nano-silver.

10. A monitoring device, comprising a light source, a detector, an output device, a pear-shaped optical fiber LSPR as described in any one of claims 7-9, and an optical fiber patch cord, wherein the pear-shaped optical fiber LSPR is connected to a portion of the light source and a portion of the detector via the optical fiber patch cord, and the other end of the detector is connected to the output device via the optical fiber patch cord.

Images