Hydrogel optical fiber sensor for monitoring blood glucose through expiration and application of hydrogel optical fiber sensor

Abstract

The invention provides a hydrogel optical fiber sensor for monitoring blood glucose through expiration and application of the hydrogel optical fiber sensor, and belongs to the technical field of diabetes monitoring. The hydrogel optical fiber sensor comprises hydrogel optical fibers, a Teflon tube and an air chamber; a gas collecting opening is formed in the top of the gas chamber; the Teflon tube is arranged in the gas chamber, and a liquid injection port and a liquid discharge port are formed in the Teflon tube; one end of the hydrogel optical fiber is arranged in the Teflon tube, and the other end of the hydrogel optical fiber penetrates through the air chamber; according to the present invention, the polyvinylpyrrolidone in the hydrogel optical fiber adsorbs the acetone in the exhaled gas, after the acetone enters the hydrogel, the enzyme solution in the Teflon tube can reduce the acetone and oxidize the fluorescent indicator in the hydrogel optical fiber so as to consume the fluorescent indicator, and the content of the acetone in the exhaled gas is reflected according to the consumption of the fluorescent indicator; the purpose of monitoring blood glucose is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of diabetes monitoring, and in particular relates to a hydrogel optical fiber sensor for monitoring blood sugar in breath and an application thereof. Background Art

[0002] Diabetes can cause serious complications in other organs, such as the kidneys, liver, and heart. In addition, the incidence of complications is extremely high. Therefore, accurate monitoring of blood sugar levels in the body is an important indicator for the treatment of diabetes. Currently, by controlling blood sugar, diabetic patients can obtain healthy physiological information and effectively and actively control the disease.

[0003] Currently, the most accurate method for blood sugar testing is to go to a medical institution to measure venous blood. In order to monitor blood sugar levels in real time, the most common method is to measure fingertip blood sugar. During the fingertip blood sugar test, you need to prick your finger with a needle and use an enzyme-containing test strip to measure the blood sugar concentration. Although the fingertip blood sugar test can accurately detect blood sugar levels, it will cause pain during the test and is prone to wound infection, which not only increases the patient's pain during the test but may also cause other infectious diseases. In addition, enzyme-containing test strips are not easy to store, and long-term storage will affect their test results.

[0004] There are many blood glucose monitoring devices on the market, but none of them is completely non-invasive. Some parts need to be implanted subcutaneously regularly during the detection process. In addition to the pain when piercing the skin, the presence of foreign matter under the skin can cause discomfort to the patient and there is a certain risk of infection. The adhesives used in continuous blood glucose monitoring systems can cause skin irritation and contact dermatitis in some cases. In addition, in blood glucose monitoring devices, most of them fix glucose oxidase on a peroxide electrode. The hydrogen peroxide generated during the detection process is proportional to glucose. The hydrogen peroxide contacts the peroxide electrode to generate an electrical signal for judging blood glucose. However, it is easily affected by oxygen and other sugars during the detection process, which in turn affects the test results. Summary of the invention

[0005] In order to solve the problem that the existing methods of monitoring blood sugar of diabetic patients may cause certain trauma and risks, the present invention provides a hydrogel optical fiber sensor for monitoring blood sugar in breath and its application.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0007] In a first aspect, the present invention provides a hydrogel optical fiber sensor for monitoring blood sugar in breath, which is used to adsorb and detect acetone in exhaled gas, and judge the blood sugar level according to the detected acetone content;

[0008] The hydrogel optical fiber sensor comprises a hydrogel optical fiber, a Teflon tube, and an air chamber;

[0009] A gas collecting port is provided on the top of the gas chamber;

[0010] The Teflon tube is arranged in the air chamber, and the Teflon tube is provided with a liquid injection port and a liquid discharge port;

[0011] One end of the hydrogel optical fiber is disposed in the Teflon tube, and the other end of the hydrogel optical fiber passes through the air chamber;

[0012] The hydrogel optical fiber is prepared by the following method:

[0013] Polyvinyl pyrrolidone, a photoinitiator, polyethylene glycol diacrylate and water are mixed to obtain a precursor solution, an optical fiber is placed in the precursor solution, and under ultraviolet irradiation, the precursor solution is solidified on the surface of the optical fiber to obtain a hydrogel optical fiber loaded with polyvinyl pyrrolidone, which is then placed in a fluorescent indicator and under ultraviolet irradiation, the fluorescent agent is loaded onto the hydrogel optical fiber.

[0014] The optical fiber is a tapered optical fiber, the length of the tapered optical fiber is 600 μm, the transition zone is 450 μm, and the cone waist diameter is 10 μm; the optical fiber cladding diameter is 125 μm, the core diameter is 105 μm, and the tapered zone length of the drawn tapered optical fiber is 600 μm and the cone waist diameter is 10 μm. The tapered optical fiber in the present invention is more stable, and the volume of the solidified gel is relatively larger.

[0015] The present invention utilizes the performance of hydrogel that can accommodate response matrix. By loading polyvinyl pyrrolidone and fluorescent material into the hydrogel, polyvinyl pyrrolidone adsorbs acetone gas, gas molecules enter the hydrogel and interact with the fluorescent material, the fluorescent signal changes, and the change of the fluorescent material is reflected by the output signal, thereby reflecting the content of acetone in the gas, and judging the blood sugar level according to the content of acetone, so as to effectively avoid the problem of inaccurate results due to oxygen and other sugar substances during the detection process. The entire detection process is a completely non-invasive detection and will not cause trauma to the patient. In addition, the present invention combines the hydrogel with the optical fiber, and the hydrogel can not only be used as a stimulus response sensor to stimulate the phase and volume changes of the hydrogel under the change of the external environment; but also as a passive hydrogel sensor, accommodating the response matrix in its matrix, interacting with the input signal, and generating an output signal for detecting the content of acetone in the exhaled breath.

[0016] In another preferred embodiment, the mass ratio of polyethylene glycol diacrylate monomer, photoinitiator, polyvinyl pyrrolidone and water is 200-400:1-2:40-80:120-240.

[0017] In another preferred embodiment, the optical fiber is placed in a precursor solution and the ultraviolet irradiation time is 10s to 15s; when the fluorescent agent is loaded onto the hydrogel optical fiber, the ultraviolet irradiation time is 10min to 20min; if the ultraviolet light irradiation time is too short, the fluorescent agent cannot be fixed, and if the ultraviolet light irradiation time is too long, there is too much fluorescent agent, and there is a risk of the fluorescent agent falling off, thereby affecting the detection effect.

[0018] In another preferred embodiment, the fluorescent indicator is reduced coenzyme I, and the concentration of the fluorescent agent solution is 100 μM to 500 μM.

[0019] In another preferred embodiment, the photoinitiator is 2-hydroxy-2-methyl-1-propiophenone.

[0020] In another preferred embodiment, the wall thickness of the Teflon tube is 25 μm and the length is 20 mm. The thickness of the Teflon tube affects the entry of gas and the inflow of liquid, so the wall thickness of the Teflon tube needs to be controlled, and the Teflon tube selected in the present invention is gas-permeable and liquid-impermeable, so during the detection process, after the enzyme solution is injected, the enzyme solution can be collected and reused.

[0021] The second aspect of the present invention provides a hydrogel optical fiber sensing system for monitoring blood sugar in breath, comprising the hydrogel optical fiber sensor for monitoring blood sugar in breath provided by the first aspect of the present invention, and also comprising an LED driver, a light source, an optical fiber coupler, a filter, an optical fiber spectrometer and a computer; the components are connected via an SMA905 interface optical fiber jumper; the light source is turned on by controlling the LED driver, the light emitted by the light source reaches the hydrogel optical fiber through the optical fiber coupler, and excites the fluorescent indicator, the fluorescent signal emitted by the fluorescent indicator is reversely transmitted through the optical fiber coupler and the filter to reach the optical fiber spectrometer, and the optical fiber spectrometer transmits the detected fluorescent signal to the computer.

[0022] The third aspect of the present invention provides an application of a hydrogel optical fiber sensor for monitoring blood sugar in breath to quantitatively detect acetone in exhaled air. The hydrogel optical fiber sensor for monitoring blood sugar in breath is provided by the first aspect of the present invention.

[0023] An enzyme solution is injected into a Teflon tube, and the gas to be detected is introduced into the gas chamber. The acetone in the gas to be detected is adsorbed by the polyvinyl pyrrolidone in the hydrogel optical fiber. The enzyme solution reduces the acetone, oxidizing the fluorescent substance in the fluorescent indicator and reducing the fluorescence signal. The optical fiber spectrometer obtains the fluorescence intensity of the gas to be detected based on the change in the fluorescence signal, and brings it into the fitting curve of fluorescence intensity-acetone concentration to obtain the acetone concentration of the gas to be detected.

[0024] In the present invention, gas enters the hydrogel optical fiber sensor for monitoring blood sugar in breath, polyvinyl pyrrolidone, namely PVP, in the hydrogel optical fiber absorbs acetone in the gas, and secondary alcohol dehydrogenase, namely S-ADH, reduces acetone gas to cause the consumption of fluorescent substance, namely NADH. The reduction of the fluorescent signal generated by the fluorescent substance NADH can be detected by a spectrometer, and the content of NADH consumption can reflect the content of acetone in the patient's breath, thereby monitoring the blood sugar content. In the present invention, alcohol dehydrogenase is added to the Teflon tube, and ethanol gas is passed into the gas chamber, so that the NAD in the hydrogel can be reduced. + Reduction to NADH allows the hydrogel optical fiber device to be used for long-term monitoring.

[0025] In another preferred embodiment, the enzyme solution is obtained by mixing PB buffer solution or PBS buffer solution with secondary alcohol dehydrogenase.

[0026] In another preferred embodiment, the usage ratio of PB buffer solution or PBS buffer solution to the secondary alcohol dehydrogenase is 300 μL to 600 μL: 1 mg to 2 mg.

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

[0028] The hydrogel optical fiber sensor for monitoring blood sugar by exhalation in the present invention utilizes the performance of hydrogel that can accommodate the response matrix, and polyvinyl pyrrolidone and fluorescent substances are loaded into the hydrogel, polyvinyl pyrrolidone adsorbs acetone gas, gas molecules enter the hydrogel and interact with the fluorescent substance, the fluorescent signal changes, and the change of the fluorescent substance is reflected by the output signal, thereby reflecting the gas content. The hydrogel optical fiber sensor for monitoring blood sugar by exhalation in the present invention can achieve non-invasive treatment, will not cause discomfort and adverse reactions to patients during the monitoring process, and has high detection sensitivity, high accuracy, simple structure, reusability, and a detection time of less than 10 minutes. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of the hydrogel optical fiber sensor for monitoring blood sugar in breath in Example 2 of the present invention.

[0030] Figure 2 This is a schematic diagram of the hydrogel optical fiber sensing system for monitoring blood sugar in breath in Example 2 of the present invention.

[0031] Figure 3 This is a fitting curve diagram of the fluorescence intensity of NADH and the acetone concentration in Example 3 of the present invention, wherein NADH is reduced coenzyme I.

[0032] Figure 4 This is a diagram of the hydrogel optical fiber in Example 1 of the present invention.

[0033] Figure 5 This is the SEM image of the hydrogel in Example 1 of the present invention.

[0034] Explanation of the reference numerals: 1-Teflon tube, 2-hydrogel optical fiber, 3-liquid discharge port, 4-liquid injection port, 5-gas chamber, 6-gas collection port, 7-gas chamber door, 8-LED driver, 9-light source, 10-optical fiber coupler, 11-filter, 12-optical fiber spectrometer, 13-computer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] There are many blood glucose monitoring devices on the market, but none of them are completely non-invasive. Some parts need to be implanted subcutaneously at regular intervals during the detection process. In addition to the pain when piercing the subcutaneous tissue, the presence of foreign bodies under the skin can cause discomfort to patients and pose a certain risk of infection. In addition, the adhesives used in continuous blood glucose monitoring systems can cause skin irritation and contact dermatitis in some cases.

[0037] The exhaled air of diabetic patients contains a higher concentration of acetone gas than that of healthy people. Acetone exists in the human blood, and exhaled air is the product of pulmonary circulation when blood flows through the lungs. The concentration of acetone in the exhaled air of normal people is 0.3ppm~0.9ppm. Diabetics are defined as those with an acetone concentration higher than 0.9ppm, and the concentration of acetone in the exhaled air of some diabetic patients even exceeds 1.8ppm. This is mainly because when the body cannot produce enough insulin to break down blood sugar, fat is the main energy source. The liver breaks down fat into ketone bodies with relatively small molecules, such as acetoacetate, 3-β-hydroxybutyrate, and acetone, which then enter the blood. Acetone is discharged as exhaled air after circulating with the blood through the lungs. Therefore, it is scientifically based to monitor blood sugar by detecting exhaled air.

[0038] The embodiment of the present invention provides a hydrogel optical fiber sensor for monitoring blood sugar in breath. Polyvinyl pyrrolidone and fluorescent substances are loaded into the hydrogel. Polyvinyl pyrrolidone adsorbs acetone gas. Gas molecules enter the hydrogel and interact with the fluorescent substance. The fluorescent signal changes. The output signal reflects the change of the fluorescent substance, thereby reflecting the concentration of acetone in the gas and comparing it with the acetone concentration in the breath of a normal person to judge the blood sugar level. The entire detection process does not involve invasive detection and will not cause trauma. The blood sugar level is judged only by the content of acetone in the breath, which avoids the problem of inaccurate detection results caused by oxygen and other sugars in the prior art, and effectively improves the detection accuracy.

[0039] The CAS number of polyvinyl pyrrolidone in the following examples is 9003-39-8; the CAS number of polyethylene glycol diacrylate is 26570-48-9.

[0040] Example 1

[0041] A method for preparing a hydrogel optical fiber comprises the following steps:

[0042] S1. Add 500 mg of polyethylene glycol diacrylate, 2.5 mg of 2-hydroxy-2-methyl-1-phenylpropiotone and 100 mg of polyvinyl pyrrolidone powder into a 2 mL test tube, add 300 mg of deionized water, and rotate the test tube in a mini vortex mixer at 2000 rpm for 1 min to obtain a precursor solution.

[0043] S2. Insert the tapered end of the single-ended tapered optical fiber vertically into the precursor solution and irradiate it under ultraviolet light excitation for 13 seconds. The light is transmitted to the tapered tip of the single-ended tapered optical fiber, and a dense three-dimensional network, i.e., hydrogel, is formed on the surface of the tapered tip to obtain a hydrogel optical fiber loaded with polyvinyl pyrrolidone; wherein the length of the single-ended tapered optical fiber is 600 μm, the transition zone is 450 μm, the cone waist diameter is 10 μm, and the wavelength of ultraviolet light excitation is 340 nm.

[0044] S3. Weigh 0.34 mg of NADH and dissolve it in 1 mL of deionized water. Use a mini vortex mixer to mix well to obtain a NADH solution. Take out the hydrogel optical fiber loaded with polyvinyl pyrrolidone, vertically place it in a 500 μM NADH solution, irradiate it under ultraviolet light for 10 minutes, then take out the optical fiber to obtain a hydrogel optical fiber loaded with a fluorescent indicator; wherein the wavelength of ultraviolet light excitation is 340 nm. Figure 4 The SEM images of the hydrogel are shown in Figure 5 shown.

[0045] Example 2

[0046] A hydrogel optical fiber sensor for monitoring blood sugar in breath, such as Figure 1 The hydrogel optical fiber sensor shown includes the hydrogel optical fiber 1 prepared in Example 1, a Teflon tube 2, and an air chamber 5;

[0047] The air chamber 5 is a black acrylic box with a length of 9 cm and a bottom and height of 8 cm. Air chamber doors 7 are provided on both sides of the air chamber 5, and the air chamber doors 7 can be opened. A hole is drilled above the air chamber using a drill, and a plastic tube with an inner diameter of 3 cm and an exhalation port is inserted into the hole as a gas collection port 6.

[0048] The Teflon tube 2 is permeable to gas but not to liquid, has a wall thickness of 25 μm and a length of 20 mm; the Teflon tube 2 is arranged in the air chamber 5, the tapered end of the hydrogel optical fiber 1 is inserted 10 mm into the Teflon tube 2, and the two ends of the Teflon tube 2 are sealed by laser melting; a liquid inlet 4 and a liquid outlet 3 with a diameter of 100 μm are ablated on the upper and lower sides of the Teflon tube 2 by laser.

[0049] Example 3

[0050] A hydrogel optical fiber sensing system for monitoring blood sugar in breath, such as Figure 2 As shown, the hydrogel optical fiber sensor for monitoring blood sugar in breath in Example 2 also includes an LED driver 8, a light source 9, an optical fiber coupler 10, an optical filter 11, an optical fiber spectrometer 12, and a computer 13. The components are connected via an SMA905 interface optical fiber jumper. The optical filter 11 can allow light with a wavelength higher than 400nm to enter the optical fiber spectrometer 12.

[0051] The light source 9 is turned on by controlling the LED driver 8. The light emitted by the light source 9 reaches the hydrogel optical fiber 2 through the optical fiber coupler 10 and excites the fluorescent indicator. The fluorescent signal emitted by the fluorescent indicator is transmitted in reverse through the optical fiber coupler 10 and the filter 11 to the optical fiber spectrometer 12. The optical fiber spectrometer 12 transmits the detected fluorescent signal to the computer 13.

[0052] Example 4

[0053] A quantitative detection of acetone in exhaled gas, using the hydrogel optical fiber sensing system for monitoring blood sugar in exhaled gas in Example 3 to quantitatively detect acetone in exhaled gas, the specific process is as follows:

[0054] S1, open the air chamber door 7, use a syringe to inject the secondary alcohol dehydrogenase solution into the Teflon tube 1 from the liquid injection port 4 until it is full, close the air chamber door 7, discharge the gas exhaled from the nose into the air chamber through the exhalation port 6, and close the exhalation port 6; wherein the specific preparation process of the secondary alcohol dehydrogenase solution is as follows:

[0055] 1 mg of secondary alcohol dehydrogenase was weighed and dissolved in 300 μL of PBS buffer with a pH of 6.5, and the mixture was rotated for 1 min using a mini vortex mixer.

[0056] S2, after the gas enters the Teflon tube 1, the hydrogel optical fiber 2 in the Teflon tube 1 adsorbs the acetone in the gas. Under the catalysis of the secondary alcohol dehydrogenase solution, the acetone is reduced to isopropanol, and NADH is consumed to be converted into NAD + The reduction of the fluorescent substance NADH affects the change of fluorescence intensity. The light source 9 is turned on by the LED driver 8. The light emitted by the light source 9 excites NADH. After NADH is excited, the emitted fluorescence signal is reversely transmitted through the optical fiber coupler 10 and the filter 12. The signal is received by the spectrometer 13 and the computer 14 to obtain the fluorescence intensity. The fluorescence intensity obtained by the detection is brought into the fitting curve of fluorescence intensity-acetone concentration to obtain the content of acetone in the gas to be detected. Among them, the excitation wavelength is 340nm and the emission wavelength is 490nm.

[0057] The specific process of fitting the fluorescence intensity-acetone concentration curve is as follows:

[0058] Acetone solution was dissolved in deionized water to prepare acetone standard solutions of different concentrations. Acetone solutions of different concentrations were placed in the gas chamber, and the fitting curve between acetone concentration and fluorescence intensity was established by detecting the fluorescence intensity of NADH. The results are shown in Figure 2. Figure 3 As shown. The configuration of acetone standard solutions of different concentrations is as follows: acetone solutions of volumes of 0 μL, 20 μL, 80 μL, 140 μL, 200 μL, 260 μL, 320 μL, and 380 μL are injected into the gas chamber in sequence, and the obtained acetone gas concentrations are 0 ppb, 347.2 ppb, 1388.8 ppb, 2430.4 ppb, 3472 ppb, 4513.6 ppb, 5555.2 ppb, and 6596.8 ppb in sequence.

[0059] S3. After the test is completed, open the air chamber door 7 and clean the Teflon tube 1 with deionized water, then close the liquid outlet 3, weigh 1 mg of alcohol dehydrogenase powder, dissolve it with 300 μL of PBS buffer with a pH of 9, mix it on a mini vortex mixer for 1 min, inject the enzyme solution with a syringe until the Teflon tube 1 is filled, and close the air chamber door 7; pass 500 mL of ethanol gas into the air chamber 5, and then close the exhalation port 6. At this time, PVP can absorb ethanol gas into the Teflon tube. Under the action of alcohol dehydrogenase, ethanol is reduced to acetaldehyde, and NAD +Converted into NADH, when the fluorescence intensity recovers to the maximum, open the gas chamber door 7 and the liquid outlet 3, and use a liquid collecting bottle to store the buffer solution containing alcohol dehydrogenase, wherein the liquid collecting bottle collects 3 mm from the end of the Teflon tube, and the diameter is 100 μm. Then wash the Teflon tube 1 with deionized water to make the device reusable.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydrogel optical fiber sensor for monitoring blood sugar in breath, characterized in that: Used to adsorb and detect acetone in exhaled breath, and determine blood sugar level based on the detected acetone content; The hydrogel optical fiber sensor comprises a hydrogel optical fiber (2), a Teflon tube (1) and an air chamber (5); A gas collecting port (6) is provided at the top of the gas chamber (5); The Teflon tube (1) is arranged in the air chamber (5), and the Teflon tube (1) is provided with a liquid injection port (4) and a liquid discharge port (3); One end of the hydrogel optical fiber (2) is disposed in the Teflon tube (1), and the other end of the hydrogel optical fiber (2) passes through the air chamber (5); The hydrogel optical fiber (2) is prepared by the following method: Polyvinyl pyrrolidone, a photoinitiator, polyethylene glycol diacrylate and water are mixed to obtain a precursor solution; a tapered optical fiber is placed in the precursor solution, and under ultraviolet irradiation, the precursor solution is solidified on the surface of the tapered optical fiber to obtain a hydrogel optical fiber loaded with polyvinyl pyrrolidone, which is then placed in a fluorescent indicator, and under ultraviolet irradiation, the fluorescent agent is loaded on the hydrogel optical fiber.

2. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 1, characterized in that: The mass ratio of polyethylene glycol diacrylate monomer, photoinitiator, polyvinyl pyrrolidone and water is 200-400:1-2:40-80:120-240.

3. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 1, characterized in that: The tapered optical fiber is placed in a precursor solution, and the ultraviolet irradiation time is 10s to 15s; when the fluorescent agent is loaded onto the hydrogel optical fiber, the ultraviolet irradiation time is 10min to 20min.

4. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 1, characterized in that: The fluorescent indicator is reduced coenzyme I, and the concentration of the fluorescent agent solution is 100 μM to 500 μM.

5. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 1, characterized in that: The photoinitiator is 2-hydroxy-2-methyl-1-propiophenone.

6. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 1, characterized in that: The Teflon tube (1) has a wall thickness of 25 μm and a length of 20 mm.

7. A hydrogel optical fiber sensing system for monitoring blood sugar in breath, characterized in that: The hydrogel optical fiber sensor for monitoring blood glucose in breath as claimed in any one of claims 1 to 6 also comprises an LED driver (8), a light source (9), an optical fiber coupler (10), an optical filter (11), an optical fiber spectrometer (12) and a computer (13), wherein the components are connected via an SMA905 interface optical fiber jumper; The light source (9) is turned on by controlling the LED driver (8), and the light emitted by the light source (9) reaches the hydrogel optical fiber (2) through the optical fiber coupler (10), excites the fluorescent indicator, and the fluorescent signal emitted by the fluorescent indicator is transmitted in reverse through the optical fiber coupler (10) and the filter (11) to reach the optical fiber spectrometer (12), and the optical fiber spectrometer (12) transmits the detected fluorescent signal to the computer (13).

8. An application of the hydrogel optical fiber sensing system for monitoring blood sugar in breath as claimed in claim 7 for quantitative detection of acetone in exhaled gas, characterized in that: An enzyme solution is injected into a Teflon tube (1), and a gas to be detected is introduced into a gas chamber (5). After the gas to be detected enters the Teflon tube (1), acetone in the gas to be detected is adsorbed by polyvinyl pyrrolidone in the hydrogel optical fiber (2), and the enzyme solution reduces the acetone, causing the fluorescent substance in the fluorescent indicator to be oxidized and the fluorescent signal to be reduced. The optical fiber spectrometer (12) obtains the fluorescence intensity of the gas to be detected based on the change in the fluorescent signal.

9. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 8, characterized in that: The enzyme solution is obtained by mixing PB buffer solution or PBS buffer solution with secondary alcohol dehydrogenase.

10. The hydrogel optical fiber sensor for monitoring blood sugar in breath according to claim 9, characterized in that: The usage ratio of the PB buffer solution or the PBS buffer solution to the secondary alcohol dehydrogenase is 300 μL to 600 μL: 1 mg to 2 mg.

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