Beta-carotene sensor based on functional material integrated FP interferometer

Abstract

The invention provides a beta-carotene sensor based on a functional material integrated FP interferometer, and relates to the technical field of optical fiber sensing devices and biomolecule detection. The biomolecule sensor comprises a super-continuum light source, an optical fiber circulator connected with the super-continuum light source through an input single-mode optical fiber, a functional material integrated FP (Fabry-Perot) cavity and a spectrum analyzer connected with the optical fiber circulator through an output single-mode optical fiber. And the reflecting surface of the functional material integrated FP cavity comprises a first reflecting surface of the functional material integrated FP cavity formed by the reflecting end surface of the optical fiber circulator and air, and a second reflecting surface of the functional material integrated FP cavity formed by air and a functional material ultraviolet curing polymer. As an all-fiber structure, the optical fiber sensor has the advantages of low cost, reusability, simplicity in operation, high sensitivity and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber sensor devices and biomolecule detection, and in particular relates to a beta-carotene sensor based on a functional material integrated FP interferometer. Background Art

[0002] β-Carotene is a carotenoid, an orange-yellow fat-soluble compound that is widely found in various plants, algae, fungi and bacteria. It is not only a good source of vitamin A, but also has anti-tumor, antioxidant, anti-inflammatory, and immune-enhancing functions, and is widely used in medicine, food, cosmetics and other fields. However, if the human body consumes excessive amounts of β-carotene, it will be harmful to health; if this orange pigment enters the blood in large quantities, it will turn the skin yellow and cause carotenemia, thereby damaging liver and kidney function and even causing carotenemia. Therefore, it is of great significance to develop a highly sensitive, convenient and fast β-carotene sensor.

[0003] The working principle of fiber optic biosensors is mainly based on the changes in optical signals generated by the interaction between light in the optical fiber and biomolecules. These changes can be changes in light intensity, phase, polarization or wavelength. By detecting these changes, the presence and concentration of target analytes can be detected. Compared with traditional electrochemical biosensors, colorimetric sensors or other conventional sensors, fiber optic biosensors have great potential in biomolecule detection due to their higher flexibility, sensitivity and anti-electromagnetic interference ability.

[0004] In order to further improve the sensitivity and specificity, photothermal spectroscopy is combined. Photothermal spectroscopy is a specific and highly sensitive detection method that measures spectral changes caused by the light absorption of the sample, including wavelength drift and intensity changes of the spectrum. The photothermal effect of molecules causes the internal structure of the molecules to vibrate and generate thermal signals when the sample is irradiated by a laser beam of a specific wavelength. And the photothermal signal of the sample is only related to their selective absorption, while the light energy damage caused by scattering and reflection will not produce photothermal signals, reducing the noise in the sensing process. According to the Beer-Lambert law, within a certain range, the light absorbance of the molecule to be measured is positively phased with its concentration, that is, the change in the photothermal signal can reflect the change in the concentration of the molecule to be measured.

[0005] The FP interferometer is based on the principle of light interference and consists of two or more reflective surfaces. After entering the interferometer, the original light beam is reflected by the reflective surface and interference occurs. The interference signal contains the change in the length of the FP interferometer cavity or the refractive index of the medium in the cavity. The information of the change in cavity length or the refractive index of the medium in the cavity can be obtained by demodulating the interference signal with a spectrometer, which has high sensitivity, high resolution and high integration.

[0006] Traditional biomolecule detection requires the functionalization of the sensor surface and specific labeling of the molecules to be detected, which is difficult to operate, costly, and has poor reusability. Chinese patent "CN107238586A" proposes a fluorescent biosensor method for detecting glutathione, which has good specificity, but requires specific labeling and requires more solutions, which increases the difficulty of experimental operation. Chinese patent "CN113155744B" proposes a method for quantitative detection of target proteins in serum using a micro-nano optical fiber coupler without a label biosensor, which has high sensitivity and strong applicability, but requires antibody fixation and is costly. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a β-carotene sensor based on a functional material integrated FP interferometer, which solves the problems raised in the above background technology through the following technical solutions and can achieve rapid detection of β-carotene concentration.

[0008] The first object of the present invention is to provide a β-carotene sensor based on a functional material integrated FP interferometer, comprising a supercontinuum light source, an optical fiber circulator connected to the supercontinuum light source via an input single-mode optical fiber, a functional material integrated FP cavity, a spectrum analyzer connected to the optical fiber circulator via an output single-mode optical fiber, and a laser providing absorption light for β-carotene.

[0009] Preferably, the fiber circulator includes a fiber circulator input end, a fiber circulator reflection end, and a fiber circulator output end, the fiber circulator input end is connected to the input single-mode optical fiber, the fiber circulator reflection end is used to construct a functional material integrated FP cavity, and the fiber circulator output end is connected to the output single-mode optical fiber.

[0010] Preferably, the functional material integrated into the FP cavity is a UV-curable polymer having a high thermo-optical coefficient.

[0011] Preferably, the laser is a 480nm laser.

[0012] The second object of the present invention is to provide a method for preparing the above-mentioned β-carotene sensor, wherein a functional material ultraviolet light-cured polymer is filled into an optical fiber capillary, cured by ultraviolet light to form a reflective surface, and then the reflective end of the optical fiber circulator is extended into the optical fiber capillary, and the space formed between the end face of the reflective end and the cured ultraviolet light-cured polymer constitutes a functional material integrated FP cavity, and the reflective surface of the functional material integrated FP cavity includes a first reflective surface of the functional material integrated FP cavity formed by the end face of the reflective end of the optical fiber circulator and air, and a second reflective surface of the functional material integrated FP cavity formed by air and the functional material ultraviolet light-cured polymer. The cavity length of the functional material integrated FP cavity is defined as L, and the cavity length L of the functional material integrated FP cavity can be controlled by controlling the extension distance of the reflective end of the optical fiber circulator.

[0013] Preferably, the cavity length L of the functional material integrated FP cavity is 120 μm-130 μm.

[0014] The third object of the present invention is to provide a sensing operation process of the above-mentioned β-carotene sensor, wherein the functional material integrated FP cavity is placed in a solution to be tested, and a laser is used to vertically irradiate the solution with a laser. Since the β-carotene molecules have light absorption characteristics at 480nm, they absorb photon energy to generate heat energy, which increases the temperature of the solution to be tested, thereby causing the functional material in the functional material integrated FP cavity to undergo thermal expansion, causing the morphology of the functional material integrated FP cavity to change, which is specifically manifested in the shortening of the cavity length. The optical signal is received by the spectrometer to complete the detection of the solution to be tested.

[0015] Beneficial effects of the present invention:

[0016] (1) The present invention relates to a β-carotene sensor based on a functional material integrated FP interferometer, which has the advantages of simple structure, convenient operation, low cost, etc. In addition, as an all-fiber structure, all information is transmitted through optical signals, and it has the advantages of stable structure, fast response speed, and anti-electromagnetic interference, and has potential application potential in biomedicine.

[0017] (2) The present invention relates to a method for manufacturing a β-carotene sensor based on a functional material integrated FP interferometer. Compared with optical fiber FP interferometers manufactured by other methods, the manufacturing method of the β-carotene sensor is simple. It does not use the method of fusing hollow-core optical fibers or other special optical fibers to manufacture the FP interference cavity. Instead, it uses functional materials to fill and form the FP interference cavity reflection surface, thereby simplifying the sensing structure and reducing the experimental cost.

[0018] (3) The present invention relates to a sensing operation process of a β-carotene sensor based on a functional material integrated FP interferometer, which is combined with photothermal spectroscopy, so that the sensor has the advantages of high specificity and high sensitivity based on the unique light absorption characteristics of β-carotene at 480nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0020] Figure 1 The schematic diagram of the overall structure of the sensor used for β-carotene detection;

[0021] Figure 2 Schematic diagram of the structural details of the FP cavity for integrating functional materials.

[0022] In the figure: 1. supercontinuum light source; 2. input single-mode optical fiber; 3. input end of optical fiber circulator; 4. reflection end of optical fiber circulator; 5. functional material integrated FP cavity; 6. output end of optical fiber circulator; 7. output single-mode optical fiber; 8. optical spectrum analyzer; 9. laser; 10. first reflection surface of functional material integrated FP cavity; 11. second reflection surface of functional material integrated FP cavity. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods and drawings.

[0024] The term "and / or" as used herein includes any and all combinations of one or more of the related listed items. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and the instruments used in the examples are commercially available. All technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention in this application are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment provides a β-carotene sensor based on a functional material integrated FP interferometer, including a supercontinuum light source 1, an optical fiber circulator input end 3, an optical fiber circulator reflection end 4, an optical fiber circulator output end 6, an input single-mode optical fiber 2, an output single-mode optical fiber 7, a functional material integrated FP cavity 5, a functional material integrated FP cavity first reflection surface 10, a functional material integrated FP cavity second reflection surface 11, a spectrum analyzer 8, and a laser 9. The supercontinuum light source 1 is connected to the optical fiber circulator input end 3 through the input single-mode optical fiber 2, and the optical fiber circulator output end 6 is connected to the spectrum analyzer 8 through the output single-mode optical fiber 7. In this embodiment, the laser 9 uses a 480nm laser.

[0027] The preparation method of the functional material integrated FP cavity 5 is as follows: the ultraviolet light-cured polymer is filled into the optical fiber capillary, and the ultraviolet light-cured polymer is cured to form a reflective surface, and then the reflective end 4 of the optical fiber circulator is extended into the optical fiber capillary, and a certain distance is reserved between the end face of the reflective end 4 of the optical fiber circulator and the cured ultraviolet light-cured polymer to form a space, and the space is the functional material integrated FP cavity 5. The end face of the reflective end 4 of the optical fiber circulator and the air form the first reflective surface 10 of the functional material integrated FP cavity, and the air and the functional material ultraviolet light-cured polymer form the second reflective surface 11 of the functional material integrated FP cavity. The reflective surface of the functional material integrated FP cavity 5 includes the first reflective surface 10 of the functional material integrated FP cavity and the second reflective surface 11 of the functional material integrated FP cavity, and the cavity length L of the functional material integrated FP cavity 5 is 120μm-130μm.

[0028] The sensing operation process of the β-carotene sensor is as follows: the functional material integrated FP cavity 5 is placed in the solution to be tested, the laser source is vertically irradiated on the solution by the laser 9, the morphology of the functional material integrated FP cavity 5 changes, and the spectrometer 8 receives the optical signal to complete the detection of the solution to be tested.

[0029] The working process and principle of the present application are as follows: first, the incident light is output from the supercontinuum light source 1 and enters the input end 3 of the optical fiber circulator through the input single-mode optical fiber 2. When the incident light reaches the functional material integrated FP cavity 5, due to the different refractive indices of the optical fiber end face, air and the functional material UV-cured polymer, Fresnel reflection occurs at the interface. The incident light generates a first reflected light beam with an intensity of I1 on the first reflection surface 10 of the functional material integrated FP cavity. After the incident light is transmitted to the second reflection surface 11 of the functional material integrated FP cavity, a second reflected light beam with an intensity of I2 is generated. Subsequently, the two reflected light beams interfere in the output optical fiber of the optical fiber circulator, and the formed interference light signal reaches the optical spectrum analyzer 8 via the output single-mode optical fiber 7 and is received to form a spectrum.

[0030] The expression of light intensity change is:

[0031]

[0032] Wherein, I1 and I2 represent the reflected light intensity of the first reflective surface 10 of the functional material integrated FP cavity and the reflected light intensity of the second reflective surface 11 of the functional material integrated FP cavity, respectively. Indicates phase difference;

[0033] The calculation expression is:

[0034]

[0035] Wherein, n represents the refractive index of the medium in the functional material integrated FP cavity 5, L represents the cavity length of the functional material integrated FP cavity 5, and λ represents the wavelength;

[0036] When the conditions are met When k is an integer, the interference destructive condition is met and the minimum output light intensity is located at:

[0037]

[0038] When β-carotene molecules are irradiated by laser to produce photothermal effect, the temperature change caused can be expressed as:

[0039] ΔT=ηpt[1-exp(-K(λ)D eff )]

[0040] Where η is the ratio of light absorption to heat energy conversion, p is the excitation power, and t is the irradiation time. K represents the absorption coefficient of the β-carotene solution, which is positively correlated with the concentration c of the sample. When the excitation power p and irradiation time t are fixed, the temperature change is only related to the β-carotene absorption coefficient K.

[0041] When a 480nm laser source is used to irradiate the solution vertically, the β-carotene molecules absorb photon energy to generate heat energy, which increases the temperature of the solution to be tested, thereby causing the functional material UV-cured polymer in the FP cavity to undergo thermal expansion, shortening the cavity length L of the functional material integrated FP cavity 5, which can be expressed as:

[0042] ΔL=αΔT

[0043] Where α is the thermal expansion coefficient of the functional material UV-cured polymer, and the wavelength shift of the k-level interference is:

[0044]

[0045] Test Example 1

[0046] In order to verify the high sensitivity of the β-carotene sensor, β-carotene solutions of different concentrations were used for detection, and their spectrum shifts were observed and analyzed on the spectrum analyzer 8. The β-carotene concentrations and the corresponding wavelength shifts are shown in Table 1.

[0047] Table 1 Correspondence between β-carotene concentration and wavelength offset

[0048] Experiment number β-carotene concentration Wavelength offset 1 2mg / L -0.688nm 2 4mg / L -1.368nm 3 6mg / L -2.061nm 4 8mg / L -2.747nm 5 10mg / L -3.425nm

[0049] Test Example 2

[0050] In order to verify the specificity of the β-carotene sensor, 10 mg / ml glucose solution, sodium chloride solution and ascorbic acid solution were prepared respectively. Under the same experimental conditions and operation procedures, the spectral shift was observed and analyzed. The solutions and the corresponding wavelength shifts are shown in Table 2.

[0051] Table 2 Correspondence between different solutions and wavelength offset

[0052] Experiment number Experimental solution Wavelength offset 1 glucose -0.014nm 2 ascorbic acid -0.058nm 3 Sodium chloride -0.024nm

[0053] Experimental results show that the sensitivity of the β-carotene sensor is -0.344nm / (mg / L), and it can detect concentrations as low as 0.116mg / L. In addition, the spectral shift of other molecules is negligible compared to β-carotene, proving that the sensor has high sensitivity and specificity.

[0054] The above description is a detailed description, basic principles and beneficial effects of the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Without departing from the spirit or basic features of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work based on the embodiments in the present invention belong to the scope of protection of the present invention, and all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Although this specification is described in accordance with the implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should take the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A β-carotene sensor based on functional material integrated FP interferometer, characterized in that: The invention comprises a supercontinuum light source (1), an optical fiber circulator connected to the supercontinuum light source (1) via an input single-mode optical fiber (2), a functional material integrated FP cavity, an optical spectrum analyzer (8) connected to the optical fiber circulator via an output single-mode optical fiber (7), and a laser (9) for providing absorption light for beta-carotene.

2. The β-carotene sensor according to claim 1, characterized in that The optical fiber circulator comprises an optical fiber circulator input end (3), an optical fiber circulator reflection end (4), and an optical fiber circulator output end (6); the optical fiber circulator input end (3) is connected to the input single-mode optical fiber (2); the optical fiber circulator reflection end (4) is used to construct the functional material integrated FP cavity (5); and the optical fiber circulator output end (6) is connected to the output single-mode optical fiber (7).

3. The β-carotene sensor according to claim 2, characterized in that The functional material in the functional material integrated FP cavity (5) is a UV-curable polymer.

4. The β-carotene sensor according to claim 1, characterized in that The laser (9) is a 480nm laser.

5. A method for preparing a β-carotene sensor according to any one of claims 1 to 4, characterized in that: Ultraviolet light-curing polymer is filled into an optical fiber capillary and cured by ultraviolet light to form a reflection surface. Then, the reflection end (4) of an optical fiber circulator is extended into the optical fiber capillary. The space formed between the end face of the reflection end and the cured ultraviolet light-curing polymer constitutes a functional material integrated FP cavity (5). The reflection surface of the functional material integrated FP cavity (5) comprises a functional material integrated FP cavity first reflection surface (10) formed by the end face of the optical fiber circulator reflection end (4) and air, and a functional material integrated FP cavity second reflection surface (11) formed by air and the functional material ultraviolet light-curing polymer.

6. The preparation method according to claim 5, characterized in that: The cavity length L of the functional material integrated FP cavity (5) is 120 μm-130 μm.

7. A sensing operation process of the β-carotene sensor according to any one of claims 1 to 4, characterized in that: The functional material integrated FP cavity (5) is placed in a solution to be tested, and a laser (9) is used to vertically irradiate the solution with a laser source, so that the morphology of the functional material integrated FP cavity (5) changes, and the optical spectrum analyzer (8) receives the optical signal to complete the detection of the solution to be tested.

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