Self-service breath test sensitive material with aldehyde and ketone sensitivity and its preparation method and application

Abstract

This invention relates to the field of highly sensitive and selective gas-sensitive materials. It discloses a self-service breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity, its preparation method, and its applications. First, an organic precursor is subjected to controlled thermal decomposition to obtain carbon nitride material. Then, the carbon nitride is ultrasonically treated in deionized water, followed by the addition of SnCl2·2H2O, Na3C6H5O7·2H2O, and cyclodextrin, which are mixed thoroughly. L-ascorbic acid solution is then added and stirred until a homogeneous solution is formed. Finally, a high-temperature reaction is performed, followed by centrifugation, washing, and drying to obtain the target breathalyzer sensitive material. This material has a large specific surface area and an adjustable distribution of active adsorption sites, exhibiting high sensitivity, low detection limit, strong selectivity, and strong anti-interference ability. It accurately detects acetone and nonanal, two biomarkers in human exhaled breath. It is particularly suitable for preparation into a portable self-service breathalyzer device to meet the needs of rapid testing in homes and communities.

Description

Technical Field

[0001] This invention belongs to the field of high-sensitivity, high-selectivity, and interference-resistant gas-sensitive materials technology, specifically relating to a self-service breath detection sensitive material with dual functions of aldehyde and ketone sensitivity, its preparation method, and its application. Background Technology

[0002] With the continuous development of society and people's increasing emphasis on health, the development and application of biomedical materials have a promising future. Among them, self-service home health breath testing devices have a huge market demand due to their simple operation, low cost, and widespread service. Semiconductor breath testing devices, on the other hand, have advantages such as data detection, storage, transmission, and analysis, as well as portability, non-invasiveness, and low power consumption. They can achieve rapid screening, reduce the waste of medical resources, and save human, material, and financial resources.

[0003] For example, existing breath tests use α-Fe2O3 / g-C3N4 composite materials to detect H2S content in exhaled breath; WO3 / g-C3N4 is used to monitor acetone content in exhaled breath to assist medical personnel in disease diagnosis. This demonstrates the broad market potential of self-service breath testing devices. Ketone and aldehyde molecules are typical biomarkers for many respiratory infectious diseases. Accurate detection of acetone and nonanal content in patient exhaled breath is of significant reference value for disease diagnosis and disease progression monitoring.

[0004] However, current medical breath-sensitive materials also have limitations. The most prominent problems are insufficient selectivity and anti-interference ability, making it difficult to accurately identify the complex components of human exhalation. Therefore, developing key markers for specific diseases is an important research trend. Summary of the Invention

[0005] To overcome the prominent problems of low sensitivity and poor selectivity when semiconductor sensitive materials are applied to medical testing, this invention provides a self-service breath test sensitive material with dual functions of aldehyde and ketone sensitivity, as well as its preparation method and application. This material can accurately detect acetone and nonanal molecules in human breath and is particularly suitable for use in self-service breath test devices.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity, comprising the following steps: Step 1: Weigh out an organic precursor rich in nitrogen and carbon, lay a salt layer on the organic precursor, and then obtain carbon nitride powder by sintering, heat preservation, furnace cooling, separation and grinding. Step 2: Place the carbon nitride powder in deionized water and sonicate it to obtain a mixed solution; Step 3: SnCl2·2H2O, Na3C6H5O7·2H2O, and cyclodextrin are added to the mixed solution in sequence and stirred for the first time to obtain an alkaline solution; Step 4: Add a weak reducing agent dropwise to the alkaline solution, and then stir a second time until a homogeneous solution is obtained; Step 5: Seal and heat the homogeneous solution to obtain the preparative product; Step 6: Centrifuge, wash, and dry the prepared product to obtain a breath detection sensitive material with ketone-sensitive and aldehyde-sensitive properties.

[0007] Preferably, in step 1, the organic precursor is hydroxymethylthiourea, melamine, or urea; the salt layer is composed of KCl, and the amount used is 5~30 g.

[0008] Preferably, in step 1, during sintering, an air atmosphere is used, the heating rate is 2.0~10.0 ℃ / min, the temperature is held at 450~600 ℃ for 2~8 h, and then cooled to room temperature with the furnace; The particle size of the ground carbon nitride powder is 1~6 μm.

[0009] Preferably, in step 3, during the first stirring process, the amount of SnCl2·2H2O is 0.01~0.5 mol, the amount of Na3C6H5O7·2H2O is 0.02~0.5 mol, the molar ratio of carbon nitride powder to cyclodextrin is 1:(0.01~1), and the stirring time is 0.5~1 h.

[0010] Preferably, in step 4, during the second stirring process, the weak reducing agent is L-ascorbic acid solution, the amount is 0.01~1.0 mol, and the stirring time is 1~2 h.

[0011] Preferably, in step 5, during the sealing and heating process, the temperature is 140~240 ℃ and the time is 4~24 h.

[0012] Preferably, in step 6, the detergent used for washing is a mixed solution of ethanol and deionized water, with the ethanol concentration being 98%. The drying process is carried out in air at a temperature of 60-80 ℃ for 8-6 hours.

[0013] A method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity, as described above, yields a medical breathalyzer sensitive material, which is a carbon-doped SnO with a heterostructure. x / CN sensitive materials.

[0014] The application of the aforementioned medical breath test sensitive material in detecting the content of acetone and nonanal molecules in human breath.

[0015] A sensitive component, comprising the aforementioned medical breath detection sensitive material.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing a breathalyzer-sensitive material. First, a nitrogen- and carbon-rich organic precursor is subjected to controlled thermal decomposition in air, followed by thorough grinding to obtain carbon nitride powder. Then, deionized water is added to the carbon nitride powder for ultrasonic treatment, and SnCl2·2H2O, Na3C6H5O7·2H2O, and cyclodextrin are added and stirred to form a homogeneous solution. Subsequently, L-ascorbic acid solution is added and stirred until homogeneous. Finally, the solution is transferred to a reaction vessel and placed in an oven for hydrothermal reaction. The resulting product is centrifuged, washed, and dried to obtain carbon-doped SnO. x / CN heterogeneous sensitive materials. By adjusting the chemical composition of the solution, sensitive materials with different surface morphologies and pore distributions can be obtained. These materials feature high specific surface area, high sensitivity, tunable active adsorption sites, strong targeting, and outstanding anti-interference capabilities, making them promising for applications in the medical breath test for respiratory diseases.

[0017] The medical breath detection sensitive material prepared by the above method provided by this invention, through SnO... x The incorporation of carbon into the / CN composite material results in a heterogeneous structure. The heating regime and holding time during high-temperature hydrothermal treatment allow for precise control of the composite material's composition ratio, heterojunction, and CN molecular network structure, thereby influencing the type and distribution of active adsorption sites in the sensitive material. This preparation method is simple, efficient, and safe, yielding a medical sensitive material with carbon-doped SnO. x / CN medical breath test sensitive material features a semiconductor heterostructure. The addition of carbon nitride increases the specific surface area of ​​the composite material, facilitating gas adsorption and diffusion and exposing more active adsorption sites. Furthermore, the CN / C=N sp on the carbon nitride... 2The high content of carbon bonds is beneficial for carrier conduction. Some C-(N)3 bonds are replaced by C-(C)3 bonds, and the resulting delocalized large π bonds facilitate charge transfer. The amino groups in the heteromaterial are sensitive active sites for nonanal molecules; the increased amino content at the edges significantly enhances the sensitivity of nonanal molecules. More -NH2 / =NH bonds also provide more active sites for the adsorption and diffusion of nonanal molecules. The surface of the gas-sensitive material can have specific chemical interactions with acetone, leading to a selective reaction to acetone molecules. Furthermore, acetone is a polar molecule, and the gas-sensitive material exhibits selectivity based on its polarity. The polar potential energy of the material interacts well with the polarity of acetone, resulting in a high gas-sensitive response to acetone. The addition of L-ascorbic acid leads to the formation of SnO, resulting in oxygen vacancies and promoting the chemisorption of oxygen, thus further improving the sensitivity of the heteromaterial. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the preparation method of a self-service breath detection sensitive material with dual functions of aldehyde and ketone sensitivity according to the present invention. Figure 2 The XRD patterns are of the medical breath detection sensitive materials prepared in Examples 1-4 of this invention. Figure 3 These are gas-sensing performance diagrams of the medical breath detection sensitive materials prepared in Examples 1-4 of the present invention; wherein, A is the gas-sensing performance diagram of acetone and B is the gas-sensing performance diagram of nonanal. Figure 4 A comparison of the sensitivity of the optimal sample SCN4 and pure SnO2 to acetone and nonanal at different concentrations; Figure 5 A comparison of the sensitivity of the optimal sample SCN4 and pure SnO2 to acetone and nonanal under different atmospheres. Figure 6 The graph shows a comparison of the responses of the optimal sample SCN4 and pure SnO2 to 100 ppm acetone and 50 ppm nonanal gas at different relative humidity levels. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention. The present invention will be further described in detail below with reference to the accompanying drawings: This invention provides a method for preparing a sensitive material for medical breath testing, comprising the following steps: A method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity, comprising the following steps: Step 1: Weigh an organic precursor rich in nitrogen and carbon, and lay a 5-30 g salt layer on the organic precursor. Then, after sintering, heat preservation, furnace cooling, separation and grinding, carbon nitride powder with a particle size of 1-6 μm is obtained.

[0020] The organic precursor is hydroxymethylthiourea, and the salt layer is composed of KCl. The amount of salt layer is used to control the thermal decomposition rate of the precursor. Nitrogen- and carbon-rich organic precursors include, but are not limited to, hydroxymethylthiourea, melamine, or urea.

[0021] During sintering, an air atmosphere is used, the heating rate is 2.0~10.0 ℃ / min, and the temperature is held at 450~600 ℃ for 2~8 h, followed by furnace cooling to room temperature. Separation involves removing the top salt layer and grinding the underlying carbon nitride product.

[0022] Specifically, the process involves weighing an organic precursor rich in nitrogen and carbon and placing it in a ceramic crucible. A salt layer is then laid on the precursor to regulate its decomposition rate. The precursor is sintered in a muffle furnace and kept at a certain temperature for a period of time. After cooling in the furnace, the product is removed, separated, and thoroughly ground to obtain carbon nitride powder.

[0023] Step 2: Place the carbon nitride powder in deionized water and sonicate it to obtain a mixed solution; Step 3: SnCl2·2H2O, Na3C6H5O7·2H2O, and cyclodextrin are added sequentially to the mixed solution and stirred for the first time to obtain an alkaline solution; wherein, the amount of SnCl2·2H2O is 0.01~0.5 mol, the amount of Na3C6H5O7·2H2O is 0.02~0.5 mol, the molar ratio of carbon nitride powder to cyclodextrin is 1:(0.01~1), and the stirring time is 0.5~1 h.

[0024] Step 4: Add a weak reducing agent dropwise to the alkaline solution, then stir a second time until a homogeneous solution is obtained; wherein, the weak reducing agent is L-ascorbic acid solution, and the amount used is 0.01~1.0 mol, and the added L-ascorbic acid is used to adjust the composition of tin oxides with different valence states. The stirring time is 1~2 h.

[0025] Step 5: Seal and heat the homogeneous solution to obtain the preparative product; specifically, transfer the homogeneous solution into a high-pressure reactor lined with polytetrafluoroethylene and seal and heat it at 140~240 °C for 4~24 h.

[0026] Step 6: Centrifuge, wash, and dry the prepared product to obtain a breathalyzer sensitive material with ketone- and aldehyde-sensitive properties. During washing, the detergent is a mixed solution of ethanol and deionized water, with an ethanol concentration of 98%. Drying is carried out in air at a temperature of 60–80 °C for 8–6 hours.

[0027] This invention first involves the controlled thermal decomposition of hydroxymethylthiourea to obtain carbon nitride material; then, the carbon nitride is ultrasonically treated in deionized water, and SnCl2·2H2O, Na3C6H5O7·2H2O, and cyclodextrin are added under magnetic stirring and mixed evenly, followed by the addition of L-ascorbic acid solution and stirring until a homogeneous solution is formed; finally, the solution is transferred to a reaction vessel, reacted at high temperature, and the product is centrifuged, washed, and dried to obtain the target breath detection sensitive material.

[0028] Example 1 Step 1: Weigh hydroxymethylthiourea and place it in a ceramic crucible. Spread a 15 g KCl salt layer on the hydroxymethylthiourea and then place it in a muffle furnace. Heat the crucible to 500 °C at a heating rate of 3 °C / min and hold for 3 h. Then cool the crucible with the furnace and remove the product. Grind the product in a mortar to obtain a light yellow carbon nitride powder. Step 2: Weigh 0.7 mmol of carbon nitride powder, dissolve it in 40 mL of deionized water, and sonicate for 2 h to obtain solution A; Step 3: 0.01 mol L nCl2·2H2O, 0.1 mol L Na3C6H5O7·2H2O and cyclodextrin are gradually added to solution A and stirred continuously for 12 h to obtain solution B. The molar ratio of carbon nitride powder to cyclodextrin is 1:0.2. Step 4: Slowly add L-ascorbic acid solution dropwise to solution B and stir until a homogeneous solution C is formed. The volume ratio of deionized water to L-ascorbic acid solution is 1:0.5, and the amount of L-ascorbic acid used is 0.02 mol. Step 5: Transfer the homogeneous solution C into a polytetrafluoroethylene-lined high-temperature reactor and place it in an oven at 160 °C for hydrothermal reaction for 8 h to obtain the preparative product. Step 6: After the reaction is complete, the prepared product is centrifuged, washed, and dried at 60 °C for 12 h in air. The product is then collected to obtain a medical breath-sensitive material with high sensitivity and selectivity, suitable for screening respiratory infectious diseases.

[0029] Example 2 Step 1: Weigh hydroxymethylthiourea and place it in a ceramic crucible. Spread 20 g of KCl salt layer on the hydroxymethylthiourea and place it in a muffle furnace. Heat the crucible to 500 °C at a heating rate of 3 °C / min and hold for 5 h. After cooling with the furnace, take out the product and grind it thoroughly in a mortar to obtain a light yellow carbon nitride powder. Step 2: Weigh 0.8 mmol of carbon nitride powder, dissolve it in 40 mL of deionized water, and sonicate for 2 h to obtain solution A; Step 3: Add 0.3 mol L of SnCl2·2H2O, 0.3 mol L of Na3C6H5O7·2H2O and cyclodextrin to solution A and stir continuously for 12 h to obtain alkaline solution B. The molar ratio of carbon nitride powder to cyclodextrin is 1:0.4. Step 4: Slowly add L-ascorbic acid solution dropwise to alkaline solution B and stir until a homogeneous solution C is formed. The volume ratio of deionized water to L-ascorbic acid solution is 1:0.5, and the amount of L-ascorbic acid used is 0.04 mol. Step 5: Transfer the homogeneous solution C into a polytetrafluoroethylene-lined high-temperature reactor and place it in an oven at 180 °C for hydrothermal reaction for 10 h to obtain the preparative product. Step 6: After the reaction is complete, the prepared product is centrifuged, washed, and dried at 80 °C for 12 h in air. The product is then collected to obtain a medical breath-sensitive material with high sensitivity and selectivity, suitable for screening respiratory infectious diseases.

[0030] Example 3 Step 1: Weigh out hydroxymethylthiourea and place it in a ceramic crucible. Spread a layer of KCl on the hydroxymethylthiourea, using 25g. Place it in a muffle furnace and heat it to 550℃ at a heating rate of 5℃ / min. Hold it at that temperature for 3 hours. After cooling with the furnace, take out the product and grind it thoroughly in a mortar to obtain a light yellow carbon nitride powder. Step 2: Weigh 0.8 mmol of carbon nitride powder, dissolve it in 40 mL of deionized water, and sonicate it for 4 h to obtain mixed solution A; Step 3: Add 0.5 mol L of SnCl2·2H2O, 0.5 mol L of Na3C6H5O7·2H2O and cyclodextrin to solution A and stir continuously for 10 h to obtain alkaline solution B. The molar ratio of carbon nitride powder to cyclodextrin is 1:0.6. Step 4: Slowly add L-ascorbic acid solution dropwise to alkaline solution B and stir until a homogeneous solution is formed. The volume ratio of deionized water to L-ascorbic acid solution is 1:0.35, and the amount of L-ascorbic acid used is 0.06 mol. Step 5: Transfer the homogeneous solution C into a polytetrafluoroethylene-lined high-temperature reactor and place it in an oven at 180 °C for hydrothermal reaction for 10 h to obtain the preparative product. Step 6: After the reaction is complete, the product is centrifuged, washed, and dried at 60 °C for 12 h in air. The product is then collected to obtain a medical breath-sensitive material with high sensitivity and selectivity, suitable for screening respiratory infectious diseases.

[0031] Example 4 Step 1: Weigh out hydroxymethylthiourea and place it in a ceramic crucible. Spread a layer of KCl on the hydroxymethylthiourea, using 25 g. Place it in a muffle furnace and heat it to 550 ℃ at a heating rate of 7 ℃ / min. Hold it at that temperature for 5 h. After cooling with the furnace, take out the product and grind it thoroughly in a mortar to obtain a light yellow carbon nitride powder. Step 2: Weigh 0.9 mmol of carbon nitride powder, dissolve it in 40 mL of deionized water, and sonicate for 4 h to obtain mixed solution A; Step 3: Add 0.5 mol L of SnCl2·2H2O, 0.5 mol L of Na3C6H5O7·2H2O and cyclodextrin to solution A and stir continuously for 10 h to obtain alkaline solution B. The molar ratio of carbon nitride powder to cyclodextrin is 1:0.8. Step 4: Slowly add L-ascorbic acid solution dropwise to alkaline solution B and stir until a homogeneous solution C is formed. The volume ratio of deionized water to L-ascorbic acid solution is 1:0.35, and the amount of L-ascorbic acid used is 0.08 mol. Step 5: Transfer the homogeneous solution C into a polytetrafluoroethylene-lined high-temperature reactor and place it in an oven at 220 °C for hydrothermal reaction for 14 h to obtain the preparative product. Step 6: After the reaction is complete, the prepared product is centrifuged, washed, and dried at 80 °C for 14 h in air. The product is then collected to obtain a medical breath-sensitive material with high sensitivity and selectivity, suitable for screening respiratory infectious diseases.

[0032] Figure 2 The XRD patterns of the composite materials prepared in Examples 1-4 are shown. The composite material obtained in Example 1 corresponds to SNC1, in Example 2 to SNC2, in Example 3 to SNC3, and in Example 4 to SNC4. The main crystalline phase of the product is tin dioxide, and the four distinct diffraction peaks all belong to the tetragonal rutile structure of SnO2. Due to the low amount of L-ascorbic acid added, no SnO diffraction peaks were detected in any of the four samples. CN, due to its low content, did not show carbon nitride diffraction peaks in the XRD pattern. Due to differences in the preparation process, the cyclodextrin content in the products prepared in Examples 2, 3, and 4 was higher than that in Example 1, with Example 4 having the highest cyclodextrin content, resulting in the most significant shift in its XRD pattern compared to Example 1. The different raw material ratios and operating conditions led to differences in the sensitivity of the materials. The material prepared in Example 4 showed the best sensitivity to both acetone and nonanal, exhibiting the highest response values ​​to both gases, indicating that the material obtained by this method has excellent acetone / nonanal sensitivity.

[0033] The present invention also discloses the application of a medical breath detection sensitive material in detecting the content of acetone and nonanal molecules in human breath.

[0034] This invention also discloses a medical breathalyzer sensitive material prepared by a method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity. This medical breathalyzer sensitive material is a carbon-doped SnO with a heterostructure. x / CN sensitive materials.

[0035] The present invention also discloses a detector that uses medical breath test sensitive materials for detection.

[0036] The sensitivity characteristics of the sensitive materials prepared in Examples 1-4 to different concentrations of acetone and nonanal gas were tested using a gas-sensitive tester.

[0037] The detection method is as follows: the prepared sample is ground and then mixed with deionized water and binder to form a slurry, which is then coated onto the surface of an Al2O3 ceramic tube to prepare a gas-sensitive element, and then welded onto a gas-sensitive detector; the gas-sensitive element is then aged at 290 °C for 72 h; finally, an appropriate amount of the gas to be tested is injected into the detection chamber to make the atmosphere concentration in the detection chamber reach the set value, the resistance change of the gas-sensitive element is detected, and the response value of the material to the atmosphere of the specified concentration is calculated based on the resistance change.

[0038] Test results as follows Figure 3 As shown, the SNC4 sample exhibited the best sensitivity in both acetone and nonanal atmospheres, with the highest sensitivity; the SNC4 sample had a sensitivity of 31.2 for 100 ppm acetone and a sensitivity of 62.3 for 50 ppm nonanal.

[0039] Figure 4 The graph shows a comparison of the sensitivity of the optimal sample SCN4 and pure SnO2 to acetone and nonanal at different concentrations. It can be seen that the optimal sample SCN4 has a much higher sensitivity to acetone / nonanal than pure SnO2, which means that the gas-sensing performance of the material can be significantly enhanced by combining it with carbon nitride and carbon doping. Figure 5 (a) The selective response of the optimal sample SCN4 and pure SnO2 to interfering gases such as formaldehyde, ethanol, methane and toluene at 100 ppm acetone gas. Figure 5 (b) shows the selective responses of the optimal sample SCN4 and pure SnO2 to glutaraldehyde, formaldehyde, ethanol, and methylamine at 50 ppm nonanal gas. This indicates that the optimal sample SCN4 has good selectivity for acetone / nonanal gas, demonstrating the material's anti-interference ability. Figure 6Figures (a) and (b) show the comparative responses of the optimal sample SCN4 and pure SnO2 to 100 ppm acetone and 50 ppm nonanal gas under different relative humidities, respectively. When the relative humidity increases from 30% to 90%, the responses of both the optimal sample SCN4 and pure SnO2 decrease significantly. Under different humidity conditions, the optimal sample SCN4 still shows the highest response. Generally, the adsorption of water molecules on the material surface leads to a reduction in oxygen species, thus resulting in a decrease in the material's response. However, the optimal sample SCN4 can detect acetone / nonanal even under abnormally humid conditions.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity, characterized in that, The steps are as follows: Step 1: Weigh out an organic precursor rich in nitrogen and carbon, lay a salt layer on the organic precursor, and then obtain carbon nitride powder by sintering, heat preservation, furnace cooling, separation and grinding. Step 2: Place the carbon nitride powder in deionized water and sonicate it to obtain mixed solution A; Step 3: SnCl2·2H2O, Na3C6H5O7·2H2O, and cyclodextrin are added to the mixed solution in sequence and stirred for the first time to obtain alkaline solution B; Step 4: Add a weak reducing agent dropwise to the alkaline solution, and then stir a second time until a homogeneous solution C is obtained; Step 5: Seal and heat the homogeneous solution to obtain the preparative product; Step 6: Centrifuge, wash, and dry the prepared product to obtain a breath detection sensitive material with ketone-sensitive and aldehyde-sensitive properties.

2. The method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity according to claim 1, characterized in that, In step 1, the organic precursor is hydroxymethylthiourea, melamine, or urea; the salt layer is composed of KCl, and the amount used is 5~30 g.

3. The method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity according to claim 1, characterized in that, In step 1, during sintering, an air atmosphere is used, the heating rate is 2.0~10.0 ℃ / min, and the temperature is held at 450~600 ℃ for 2~8 h, and then cooled to room temperature in the furnace. The particle size of the ground carbon nitride powder is 1~6 μm.

4. The method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity according to claim 1, characterized in that, In step 3, during the first stirring process, the amount of SnCl2·2H2O used is 0.01~0.5 mol, the amount of Na3C6H5O7·2H2O used is 0.02~0.5 mol, the molar ratio of carbon nitride powder to cyclodextrin is 1:(0.01~1), and the stirring time is 0.5~1 h.

5. The method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity according to claim 1, characterized in that, In step 4, during the second stirring process, the weak reducing agent is L-ascorbic acid solution, with a dosage of 0.01~1.0 mol, and the stirring time is 1~2 h.

6. A method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity according to claim 1, characterized in that, In step 5, during the sealed heating process, the temperature is 140~240 ℃ and the time is 4~24 h.

7. The method for preparing a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity according to claim 1, characterized in that, In step 6, during washing, the detergent is a mixed solution of ethanol and deionized water, with the ethanol concentration being 98%. The drying process is carried out in air at a temperature of 60-80 ℃ for 8-6 hours.

8. A medical breathalyzer sensitive material prepared by the preparation method of a self-administered breathalyzer sensitive material with dual functions of aldehyde and ketone sensitivity as described in any one of claims 1 to 7, characterized in that, The medical breath test sensitive material is a carbon-doped SnOx / CN sensitive material with a heterostructure.

9. The application of the medical breath detection sensitive material as described in claim 8 in detecting the content of acetone and nonanal molecules in human breath.

10. A sensitive component, characterized in that, Includes the medical breath test sensitive material as described in claim 8.

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