Dimethylamine gas catalytic luminescence sensing material, sensor, preparation and application

Abstract

The invention discloses a dimethylamine gas catalytic luminescence sensing material, a sensor, preparation and application, and belongs to the field of gas catalytic luminescence sensors, and the material preparation method comprises the following steps: dissolving a zirconium oxychloride hydrate in water, adding a chelating agent and polyhydroxy alcohol, dissolving, drying by distillation, calcining at a specific temperature, and naturally cooling. The metastable-state tetragonal-phase zirconium dioxide sensing material can be rapidly prepared, the particle size is about 10 nm, particle size distribution is uniform, agglomeration is avoided, the specific surface area is large, the sensing material can stably exist at the room temperature, the potential of rapidly detecting dimethylamine gas is achieved, and the sensing material has the advantages of being high in sensitivity, good in cycle performance and good in stability when being used for a catalytic light-emitting sensor. When the amine VOCs are continuously and repeatedly detected, good consistency is shown, dimethylamine gas can be measured with high selectivity without being interfered by other gases, reproducibility and stability are good, the gas sensor can be used for monitoring the dimethylamine gas for a long time, the response speed is high, the accuracy is high, and the service life is long.

Description

Technical Field

[0001] The invention relates to a dimethylamine gas catalytic luminescence sensing material, a sensor, and preparation and application thereof, and belongs to the field of gas catalytic luminescence sensors. Background Art

[0002] Most amine substances have a certain smell, and different amines have different smells. Low-level amines have an ammonia smell, dimethylamine has a fishy smell, and propylenediamine and butylenediamine have a foul smell. These odors are highly irritating to the respiratory tract and can cause pulmonary edema or even death after inhalation. In addition, patients with renal damage and dimethylaminuria cannot metabolize dimethylamine smoothly. Dimethylamine is released through breathing, urine, and sweat, causing a fishy smell in the patient's body. Therefore, real-time detection of dimethylamine in human exhaled breath can monitor physical health indicators and ensure human health.

[0003] At present, sensors that can specifically detect amine gases generally use semiconductor gas sensing technology, electrochemical gas sensing technology, and infrared gas sensing technology. However, semiconductor gas sensing technology has a small measurement linear range, large background gas interference, and is easily affected by ambient temperature; electrochemical gas sensing technology is easily interfered with, and its sensitivity is greatly affected by temperature changes; infrared gas sensing technology has low sensitivity and is difficult to detect target gases at the ppb level.

[0004] Cataluminescence is a special chemiluminescence phenomenon. When the target molecule passes through the surface of a specific sensitizing material, it is oxidized by oxygen in the air and emits light in the process. In the cataluminescence reaction, when the reducing substance passes through the surface of the sensitizing material together with the air, a catalytic oxidation reaction occurs to produce an intermediate product in an excited state. When the intermediate product in the excited state returns to the ground state in the form of a radiation transition, it releases a photon. Although the cataluminescence sensor based on the cataluminescence phenomenon also needs to consume oxidants and reducing agents in the sensing process, no special luminescent reagent is required in the entire reaction process. Chemiluminescence comes from the excited product produced by the catalytic oxidation of the reducing substance. The sensitizing material will not be consumed as a catalyst in the luminescence process. The entire reaction consumes only the sample analyte and oxygen in the air. This is different from the chemiluminescence sensor with an immobilized luminescent reagent. Therefore, the catalytic luminescence signal can be unaffected by the measurement time and has a long service life. On the other hand, the device of the catalytic luminescence sensor is very simple, requiring only a heating controller, a photodetector and an injection system. It can be said that the catalytic luminescence sensor is the chemiluminescence sensor that is most likely to be put into practical use. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a dimethylamine gas catalytic luminescence sensing material and a preparation method thereof, and provides a catalytic luminescence sensor using the material and a preparation method and a use method thereof. The obtained sensor has good selectivity for dimethylamine gas and strong anti-interference ability.

[0006] The technical solution adopted by the present invention to solve its technical problem is: In a first aspect, the present application provides a method for preparing a dimethylamine gas catalytic luminescent sensor material, comprising the following steps: dissolving zirconium oxychloride hydrate in water to obtain a zirconium oxychloride solution; Adding a chelating agent and a polyhydric alcohol to the zirconium oxychloride solution to dissolve and obtain a reaction solution; Heating the reaction liquid in three stages so that the reaction liquid is transformed into a sol, a gel, and a brown precursor powder in sequence, wherein the temperature in the latter stage is higher than the temperature in the former stage; The precursor powder is calcined and then cooled naturally to obtain a metastable tetragonal zirconium dioxide that emits green light under an ultraviolet lamp and has a particle size of 4nm-20nm, thereby obtaining the dimethylamine gas catalytic luminescent sensing material.

[0007] The preparation method of dimethylamine gas catalytic luminescence sensing material provided in the present application can produce metastable tetragonal zirconium dioxide particles that are stable at room temperature, are not easy to agglomerate, have a high specific surface area, and have the potential to quickly detect amine VOCs (volatile organic compounds).

[0008] Furthermore, the chelating agent is citric acid, and the polyhydroxy alcohol is triethanolamine. In the nucleation stage, citric acid can grow the initial nucleus in all directions when forming the crystal, and triethanolamine can coordinate on the high-density zirconium oxide plane, and the steric hindrance of the triethanolamine molecule causes the crystal to grow in one direction.

[0009] Furthermore, in the reaction solution, Zr 4+ The molar ratio of triethanolamine to citric acid is 1:4:4, and the Zr 4+ The molar ratio of triethanolamine to the dimethylamine is 1:4, which can form sufficient steric hindrance so that during the evaporation of the reaction liquid, the crystal grows along the special crystal axis of zirconium oxide. The molar ratio of triethanolamine to citric acid is 1:1, so that the dimethylamine gas catalytic luminescence sensing material has good sphericity.

[0010] Further, the concentration of zirconium element in the reaction liquid is 0.5 mol / L-0.8 mol / L; the step of heating the reaction liquid in three stages so that the reaction liquid is converted into sol, gel, and brown precursor powder in sequence comprises: heating the reaction liquid at 80°C-100°C for 1h-2h to obtain sol; heating the sol at 110°C-150°C for 1h to obtain gel; heating the gel at 250°C for 0.5h to obtain brown precursor powder. Evaporation crystallization is performed in conjunction with this operation to obtain high-purity zirconium dioxide particles with good sphericity, small particle size, and good crystallization.

[0011] Furthermore, the step of calcining the precursor powder and then naturally cooling it includes: placing the precursor powder in a muffle furnace, calcining it at 450°C-550°C for 1h-3h, and then cooling it with the furnace, so as to obtain high-purity metastable tetragonal zirconium dioxide that is stable at room temperature.

[0012] Furthermore, in the step of calcining the precursor powder and then naturally cooling it, the D50 particle size of the obtained metastable tetragonal zirconium dioxide is 10 nm.

[0013] Furthermore, in the steps of dissolving the zirconium oxychloride hydrate in water and adding the chelating agent and the polyhydric alcohol to the zirconium oxychloride solution, magnetic stirring is always ensured.

[0014] In the second aspect, the present application provides a dimethylamine gas catalytic luminescence sensing material, which is prepared by the dimethylamine gas catalytic luminescence sensing material preparation method described in the first aspect. It has a small particle size, is not easy to agglomerate, has good selectivity for amine VOCs, can cause amine VOCs to be oxidized by oxygen in the air to produce light signals with a wavelength of 400nm-600nm, and has stability for long-term use.

[0015] In a third aspect, the present application provides a method for preparing a dimethylamine gas catalytic luminescence sensor, comprising the following steps: The dimethylamine gas catalytic luminescent sensing material described in the second aspect is dispersed in a solvent to obtain a suspension; Applying the suspension on the surface of the heating device; drying the heating device; The heating device is installed into the gas chamber, and a photomultiplier tube is assembled to align with the heating device to obtain the dimethylamine gas catalytic luminescence sensor.

[0016] Through this method, the dimethylamine gas catalytic luminescence sensing material can be tightly loaded on the surface of the heating device, and its small particle size metastable tetragonal zirconium dioxide characteristics are retained, so that amine VOCs can be oxidized by oxygen in the air to produce light signals with high sensitivity and selectivity. In combination with a photomultiplier tube, it can be assembled into a dimethylamine gas catalytic luminescence sensor with fast response, strong resistance to background interference, good selectivity, high sensitivity, and real-time monitoring.

[0017] In a fourth aspect, the present application provides a dimethylamine gas catalytic luminescence sensor, which is prepared by the dimethylamine gas catalytic luminescence sensor preparation method described in the third aspect. The sensor has good reproducibility and stability, can be used for long-term monitoring of amine VOCs, and has the advantages of fast response speed, high accuracy, and long service life.

[0018] In a fifth aspect, the present application provides a dimethylamine gas detection method applicable to the dimethylamine gas catalytic luminescence sensor described in the fourth aspect, comprising the following steps: Controlling the heating device to generate heat at a constant temperature, wherein the constant temperature is 150° C.-400° C.; Passing sample gas into the gas chamber at a constant flow rate; Acquiring the signal intensity of the light with the wavelength as the detection wavelength collected by the photomultiplier tube; The detection wavelength is 400nm-600nm.

[0019] This method can determine amine VOCs with high sensitivity and selectivity without being interfered by other gases.

[0020] Furthermore, the constant temperature is 210° C.-350° C., the constant flow rate is 300 mL / min-1200 mL / min, and the detection wavelength is 475 nm-555 nm, which has higher sensitivity and lower detection limit.

[0021] Furthermore, the method comprises the following steps: Controlling the heating device to continuously generate heat at 210° C. Passing dimethylamine gas with different known concentrations into the gas chamber at a constant flow rate for multiple times, obtaining the signal intensity of the light with a wavelength of 535 mm collected by the photomultiplier tube each time as the calibration intensity, establishing a mathematical relationship between the calibration intensity and the corresponding dimethylamine gas concentration, and obtaining a correction function; Passing sample gas into the gas chamber at a constant flow rate; Obtaining the signal intensity of the light with a wavelength of 535 nm collected by the photomultiplier tube as the sample intensity; Substituting the sample intensity into the calibration function, the concentration of dimethylamine in the sample is obtained.

[0022] The beneficial effects of the present invention are as follows: the present invention can rapidly prepare a metastable tetragonal zirconium dioxide sensing material, the particle size distribution is relatively uniform, the particles are not agglomerated, the specific surface area is large, the particles can exist stably at room temperature, and the material has the potential to rapidly detect amine VOCs. The material is used in a catalytic luminescence sensor with high sensitivity and good cycle performance. When the amine VOCs are detected repeatedly, the material exhibits good consistency, and the material can be highly selectively determined without being interfered by other gases. The material has good reproducibility and stability, and can be used for long-term monitoring of amine VOCs. The material has a fast response speed, high accuracy, and a long service life.

[0023] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the XRD test result diagram of the dimethylamine gas catalytic luminescent sensing material prepared in Example 1.

[0025] Figure 2 This is the SEM morphology of the dimethylamine gas catalytic luminescent sensing material prepared in Example 1.

[0026] Figure 3 This is the SEM morphology of the zirconium dioxide particles prepared in Comparative Example 1.

[0027] Figure 4 It is a comparison diagram of the test results of the sensor detecting the breath of amphetamine bottle of Example 2 and Comparative Example 2.

[0028] Figure 5 It is a comparison chart of the response values ​​of zirconium dioxide at different wavelengths when the dimethylamine gas catalytic luminescence sensor prepared in the embodiment of the present application catalyzes the oxidation luminescence of dimethylamine gas.

[0029] Figure 6 This is a relationship diagram between the luminescence intensity of the dimethylamine gas catalytic luminescence sensor prepared in the embodiment of the present application and the dimethylamine gas concentration.

[0030] Figure 7 This is a comparison chart of light signal intensities obtained when the dimethylamine gas catalytic luminescence sensor prepared in the embodiment of the present application detects different gases with the same concentration. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be understood that, under the premise of no conflict, any and all embodiments of the present invention can be combined with the technical features in any other embodiment or multiple other embodiments to obtain another embodiment. The present invention includes such a combination to obtain another embodiment.

[0033] Unless otherwise specified, all technical and scientific terms used herein have the standard meanings in the field to which the claimed subject matter belongs. If there are multiple definitions for a term, the definition herein shall prevail. "au." and "au" in the drawings of the specification all represent relative values ​​of intensity, in arbitrary units.

[0034] The research results of amine VOCs based on catalytic luminescence technology show that the responsiveness of amine VOCs to chemiluminescence will change differently under different catalyst and medium conditions. Therefore, in the detection method of catalytic luminescence technology, it is necessary to select appropriate catalysts and media, and fully consider the possible interference factors in the reaction system to accurately detect amine VOCs.

[0035] In recent years, nanomaterial-based CTL gas sensors have been used for gas sensing with high sensitivity, selectivity and long life. 2 The coefficient of thermal expansion is very low, and its dimensional changes at different temperatures are smaller than many other materials. This makes the application of zirconium oxide in sensors in high temperature environments more stable and reliable, and it is an ideal raw material for amine VOCs sensors. 2It includes three phases: monoclinic, tetragonal, and cubic. The monoclinic phase structure of zirconium oxide is called monoclinic zirconia, and the unit cell contains four zirconium oxide ions and four oxygen ions. The structure of monoclinic zirconia crystals is composed of randomly arranged zirconium atoms and octahedral oxygen atoms. Among them, half of the oxygen atoms form a six-membered ring of coordinated zirconium oxygen octahedrons, while the other half of the oxygen atoms form coplanar four-membered rings. The cubic phase structure of zirconia is called cubic zirconia. In cubic zirconia, zirconium oxide and oxygen ions are arranged in a typical body-centered cubic structure, and the unit cell contains eight zirconium oxide ions and two oxygen ions. Tetragonal zirconium dioxide (tetragonal zirconia) is also called tetragonal crystal or tetragonal zircon, and the unit cell contains four zirconium oxide ions and four oxygen ions. The structure of tetragonal zirconia is between the monoclinic phase and the cubic phase, and its crystal structure can be adjusted by adding rare earth elements or by physical methods such as reducing the grain size. ZrO 2 It is a monoclinic phase at room temperature, and gradually transforms into a tetragonal phase when the temperature rises to 800°C. If the temperature continues to rise, it transforms into a cubic phase at 2300°C.

[0036] Tetragonal ZrO 2 It has better catalytic activity, and DFT calculations confirm that molecular oxygen is easily adsorbed on defective t-ZrO 2 The upper (011) surface has lower energy, and the distance between the OO bonds is elongated, which can form highly active oxygen species with superoxide characteristics. This application prepares the metastable tetragonal ZrO 2 Nanoparticles are spheres with a particle size of 4nm-20nm. By controlling the particle size of nanomaterials, metastable tetragonal zirconium dioxide can be stabilized at room temperature. Due to its small size, it has a high specific surface area, which means that nanoparticles of the same mass have more surface area than large-sized particles. This improves the interaction between the nanomaterial and the environment or the molecules to be measured, thereby improving the sensitivity of the sensor. Due to its high specific surface area, nanomaterials can interact with target molecules more effectively, thereby improving the sensitivity of the sensor. This enables the sensor to detect very low concentrations of target substances, reduces the detection limit, and realizes the detection of low-concentration amine VOCs.

[0037] The present invention provides a method for preparing a dimethylamine gas catalytic luminescent sensor material, comprising the following steps: S1: Dissolving zirconium oxychloride hydrate in water to obtain a zirconium oxychloride solution.

[0038] S2: adding a chelating agent and a polyhydric alcohol to the zirconium oxychloride solution to dissolve and obtain a reaction solution.

[0039] S3: The reaction liquid is heated in three stages so that the reaction liquid is transformed into sol, gel, and brown precursor powder in sequence, and the temperature in the latter stage is higher than the temperature in the former stage.

[0040] S4: calcining the precursor powder and then cooling it naturally to obtain a metastable tetragonal zirconium dioxide that emits green light under ultraviolet light, with a particle size of 4nm-20nm, and obtaining a dimethylamine gas catalytic luminescent sensing material.

[0041] The operation of step S3 may be: heating the reaction solution at 80°C-100°C until the Tyndall effect occurs to obtain a sol; heating the sol at 110°C-150°C until it becomes a gel; and heating the gel at 250°C until it is dry to obtain a precursor powder.

[0042] In some embodiments, preparing the dimethylamine gas catalytic luminescence sensing material comprises the following steps: Weigh zirconium oxychloride octahydrate, citric acid and triethanolamine in a molar ratio of 1:4:4. Add deionized water to a beaker, and add the weighed zirconium oxychloride octahydrate under magnetic stirring, and continue stirring to obtain a zirconium oxychloride octahydrate aqueous solution. Keep magnetic stirring, add the weighed citric acid and triethanolamine to the obtained zirconium oxychloride octahydrate solution in portions, and continue stirring to obtain a solution containing Zr 4+ Ionic reaction solution.

[0043] The reaction solution was heated at 80°C for 1 hour to obtain a sol, and the sol was further heated at 120°C for 1 hour to obtain a gel. The temperature was raised to 250°C and maintained for 0.5 hours to obtain a brown powder, which was a precursor powder.

[0044] Take a certain amount of precursor powder, put it into a porcelain boat and use a muffle furnace, calcine it at 300℃-600℃ for 1 to 3 hours, then cool it with the furnace to obtain a dimethylamine gas catalytic luminescent sensing material, which is a metastable tetragonal zirconium dioxide with a particle size of 4nm-20nm. The calcination time should not be too long to avoid phase change of the metastable tetragonal zirconium dioxide.

[0045] Preferably, the calcination temperature is 400°C-500°C.

[0046] The inventors found that by selecting the appropriate evaporation crystallization operation and calcination temperature, the zirconium oxide synthesized by this method can obtain a small particle size, a well-crystallized high-purity metastable tetragonal zirconium dioxide, and the specific D50 particle size reaches 10nm. When triethanolamine is used, the molecule can be coordinated on the high-density zirconium oxide plane (the zirconium oxide of the present application is a tetragonal phase, in which the high-density plane is usually the (101) plane, which has a higher atomic density). The steric hindrance of the triethanolamine molecule causes the crystal to grow only in a specific direction and cannot grow freely in other directions; during the crystal growth process, these crystal planes grow along the special crystal axis of the zirconium oxide; that is, due to the steric blocking of triethanolamine, the crystal can only grow along the specific crystal axis of the oxide, while the growth in other directions is inhibited. This coordination effect limits the morphology of the crystal, so that it can only extend in a specific direction. On the other hand, citric acid in the nucleation stage can grow the initial nucleus in all directions, so in this case, spherical zirconium oxide nanoparticles are obtained. Citric acid and triethanolamine have different roles in the growth of zirconium oxide crystals, but they are indirectly related to the control of crystal morphology by affecting the nucleation and growth process of the crystals. Citric acid helps to form uniform crystal nuclei and promote multi-directional crystal growth, while triethanolamine limits the growth of crystals in a certain direction through the steric hindrance effect, thereby controlling the growth direction and morphology of the crystals.

[0047] Dimethylamine (DMA) is an amine present in plasma, urine and exhaled breath. In cases of renal disease, the levels of dimethylamine concentration may increase. DMA and TMA (trimethylamine) can reflect the patient's physical signs. For example, particularly high amounts of aliphatic amines are observed in cases of end-stage renal disease (DRC). Breath gas containing amino groups has an unpleasant odor, and the concentration of aliphatic amines in the breath of healthy people is below detectable levels. In dialysis patients, plasma DMA concentrations decrease with the dialysis process. Most of the instruments used to measure aliphatic amines in human breath are based on gas chromatography coupled to mass spectrometry (GC-MS), laser photoacoustic spectroscopy (LPAS) and selective ion flux mass spectrometry (SIFT-MS). However, these techniques require expensive instruments and involve complex systems, which makes them difficult to use as routine equipment near patients or at the point of care. Direct determination of dimethylamine concentrations in breath can help monitor or diagnose metabolic disorders during dialysis, but analyzing amines in breath samples is difficult. A large amount of water vapor is present in human exhaled breath. Compared with existing sensors, most of them use MOS sensors to detect dimethylamine. Although they can detect low concentrations of dimethylamine gas, the disadvantage of MOS sensors is that they have poor anti-interference ability to water, which leads to signal fluctuations. In the sensing system based on catalytic luminescence sensing technology, the sensor operation is not interfered by water vapor. Compared with dimethylamine sensors in the field of catalytic luminescence, currently only the sensing material response range of this application can cover low concentration responses in the range of 100ppb-200ppb. Directly measuring the concentration of dimethylamine in breath can be used as a non-invasive detection method, which is helpful for monitoring or diagnosing metabolic disorders during dialysis.

[0048] Example 1 Weigh 0.1 mol of ZrOCl 2 8H 2 O, 0.4 mol of citric acid and 0.4 mol of triethanolamine. Add 200 ml of deionized water into a beaker, and add the weighed zirconium oxychloride octahydrate under magnetic stirring, and continue stirring to obtain an aqueous solution of zirconium oxychloride octahydrate. Maintain magnetic stirring, add the weighed citric acid and triethanolamine to the obtained zirconium oxychloride octahydrate solution in portions, and continue stirring to obtain a reaction solution.

[0049] The obtained reaction solution was heated at 80°C for 1 hour to obtain a sol, and the sol was further heated at 120°C for 1 hour to obtain a gel. The temperature was raised to 250°C and maintained for 0.5 hours to finally obtain a brown precursor powder.

[0050] The precursor powder was placed in a porcelain boat and calcined at 500°C for 3 hours in a muffle furnace, and then cooled in the furnace to obtain the dimethylamine gas catalytic luminescent sensing material of Example 1. 2The raw material has no fluorescence under ultraviolet light, while the dimethylamine gas catalytic luminescent sensing material of Example 1 emits green light under ultraviolet light.

[0051] The dimethylamine gas catalytic luminescent sensing material of Example 1 was subjected to an X-ray diffraction test, and the results were as follows: Figure 1 As shown in FIG. 1 , it is confirmed to be high-purity metastable tetragonal zirconium dioxide. The dimethylamine gas catalytic luminescent sensing material of Example 1 was observed under an electron microscope. Figure 2 As shown, it can be seen that the particles have high roundness and small and uniform particle size. The particle sizes of four particles are measured (in Figure 2 From left to right) are 10.05nm, 11.74nm, 12.85nm, and 12.85nm respectively.

[0052] Comparative Example 1 200 mL of deionized water was added to a beaker, and 0.1 mol of zirconium oxychloride octahydrate was added under magnetic stirring, and the solution was stirred continuously to obtain an aqueous solution of zirconium oxychloride octahydrate. 25 mL of ammonia water was used as a precipitant, and the zirconium dioxide particles of Comparative Example 1 were prepared by a hydrothermal method (180°C, 12h) .

[0053] The zirconium dioxide particles of Comparative Example 1 were observed under an electron microscope. Figure 3 As shown in the figure, the particles are angular, large and uneven in size. The particle sizes of six particles were measured (in Figure 3 From left to right) are 29.03nm, 31.07nm, 19.74nm, 32.38nm, 17.31nm, and 20.13nm respectively.

[0054] The present application also provides a method for preparing a dimethylamine gas catalytic luminescent sensor, comprising the following steps: Take 0.05 g of dimethylamine gas catalytic luminescence sensing material, and disperse it in 150 μL of solvent by ultrasonic to obtain a suspension.

[0055] Apply the suspension to the surface of the heating element.

[0056] The heating device is controlled to generate heat at 200°C-350°C for 20min-30min.

[0057] The heating device is installed into the gas chamber, and the photomultiplier tube is assembled to align with the heating device to obtain a dimethylamine gas catalytic luminescence sensor.

[0058] Example 2 The dimethylamine gas catalytic luminescence sensor material of Example 1 was ultrasonically dispersed in deionized water to obtain a suspension. The suspension was coated on a ceramic heating rod, and the ceramic heating rod was controlled to heat at 250° C. for 30 minutes to evaporate and remove the solvent. The ceramic heating rod was installed in the gas chamber, and a photomultiplier tube was assembled to align with the ceramic heating rod to obtain the dimethylamine gas catalytic luminescence sensor of Example 2.

[0059] Comparative Example 2 The zirconium dioxide particles of Comparative Example 1 were dispersed in deionized water to obtain a suspension. The suspension was applied to a ceramic heating rod, and the ceramic heating rod was controlled to heat at 250° C. for 30 minutes to evaporate and remove the solvent. The ceramic heating rod was installed in the gas chamber, and a photomultiplier tube was assembled to align with the ceramic heating rod to obtain the catalytic luminescence sensor of Comparative Example 2.

[0060] The sensor performance obtained by testing Example 2 and Comparative Example 2. The gas to be tested is the breath of amphetamine bottle. After the gas to be tested passes through the sampling device into the gas chamber, the device is heated to 210°C, the amphetamine gas contacts the zirconium dioxide, and the test gas is oxidized by the oxygen in the air on the surface of the zirconium dioxide to generate a light signal, and the intensity of the light signal is recorded. The detection wavelength of the luminescent signal is 490nm, the carrier gas is air, and the carrier gas flow rate is 300mL / min. The test results are as follows: Figure 4 As shown, it can be seen that the ability of comparative example 2 to catalyze the oxidation of dimethylamine gas to produce luminescence is not as good as that of example 2. The catalytic luminescence sensor prepared in the present application has higher detection sensitivity and lower detection limit.

[0061] Example 3 The dimethylamine gas was prepared by the headspace gas distribution method. After being introduced into the gas chamber of Example 2 through the sampling device, the ceramic heating rod was heated to 210°C, the dimethylamine gas came into contact with zirconium dioxide, and the test gas was oxidized by oxygen in the air on the surface of zirconium dioxide to generate a light signal, and the intensity of the light signal was recorded. The detection wavelength of the luminescent signal was 425nm, 475nm, 490nm, 535nm, 555nm and 590nm, the carrier gas was air, the carrier gas flow rate was 300mL / min, the dimethylamine concentration was 300ppm, and the test results were as follows: Figure 5 The experimental results show that at a concentration of 300ppm, ZrO 2 The sensor's optimal test wavelength is 535nm.

[0062] Example 4 The dimethylamine gas was prepared by the headspace gas distribution method. After passing through the sampling device into the gas chamber of Example 2, the ceramic heating rod was heated to 210°C, the dimethylamine gas came into contact with zirconium dioxide, and the test gas was oxidized by oxygen in the air on the surface of zirconium dioxide to generate a light signal, and the intensity of the light signal was recorded. The detection wavelength of the luminescent signal was 535nm, the carrier gas was air, the carrier gas flow rate was 300mL / min, the dimethylamine concentration was 80ppb-300ppm, and the test results were as follows: Figure 6 As shown, the horizontal axis is the dimethylamine concentration and the vertical axis is the luminescence intensity.

[0063] The results show that ZrO 2It shows a good linear relationship for 80ppb-300ppm dimethylamine, which provides a basis for quantitative detection of dimethylamine.

[0064] Example 5 Dimethylamine gas is prepared by the headspace gas distribution method. After the gas to be tested is sent into the catalytic luminescence reaction gas chamber through the sampling unit, the ceramic heating rod is heated to 210°C, dimethylamine contacts the catalytic layer, and the test gas is oxidized by the oxygen in the air on the surface of the catalytic layer to generate a light signal, which is detected, analyzed and displayed by the detection unit. The detection method is as follows: the test gas is replaced with 20ppm of ethanol, hydrogen sulfide, methanol, sulfur dioxide, acetone, benzene, dimethylamine and formaldehyde, respectively. Under the optimal response conditions (test wavelength of 535nm), the response intensity of the above 9 substances is detected by the comparison sensor, and the specificity of the detection gas is reflected by the size of the response intensity. The results are as follows: Figure 7 As shown, it shows that ZrO 2 It showed good selectivity towards dimethylamine.

[0065] The embodiments of the present application provide a catalytic luminescent sensing material for detecting dimethylamine gas. By controlling the particle size of the nanomaterial, the metastable tetragonal zirconium dioxide can be stabilized at room temperature, which is beneficial for the purpose of high-sensitivity and quantitative detection of amine VOCs. Zirconium dioxide nanoparticles are prepared by specific means of gel formation, crystallization, and calcination. A heating device is used as the substrate of the sensor material, and the nanomaterial is evenly coated on the surface of the heating device after being dispersed by a solvent. When the amine VOCs enter the gas chamber and flow through the surface of the sensing material, a light signal is generated and collected by a photomultiplier tube. The method of detecting amine VOCs based on the catalytic luminescence of zirconium dioxide nanomaterials of the present invention can measure amine VOCs with high sensitivity and selectivity without being interfered by other gases, and has the advantages of fast response speed, high accuracy, and long service life. Compared with other sensing technologies, the ZrO developed in this application 2 The nanoparticle sensor effectively avoids the interference of water vapor during the detection process. This advantage makes it more stable and reliable in complex practical environments. In addition, the sensor is expected to be used to monitor the concentration of dimethylamine in the exhaled breath of kidney patients. As a non-invasive and real-time detection method, it can cooperate with clinical diagnosis to provide more accurate disease assessment and monitoring solutions.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a dimethylamine gas catalytic luminescence sensing material, characterized in that: The following steps are involved: dissolving zirconium oxychloride hydrate in water to obtain a zirconium oxychloride solution; Adding a chelating agent and a polyhydric alcohol to the zirconium oxychloride solution to dissolve and obtain a reaction solution; Heating the reaction liquid in three stages so that the reaction liquid is transformed into a sol, a gel, and a brown precursor powder in sequence, wherein the temperature in the latter stage is higher than the temperature in the former stage; The precursor powder is calcined and then cooled naturally to obtain a metastable tetragonal zirconium dioxide that emits green light under an ultraviolet lamp and has a particle size of 4nm-20nm, thereby obtaining the dimethylamine gas catalytic luminescent sensing material.

2. The method for preparing the dimethylamine gas catalytic luminescence sensing material according to claim 1, characterized in that: The chelating agent is citric acid, and the polyhydroxy alcohol is triethanolamine.

3. The method for preparing the dimethylamine gas catalytic luminescence sensing material according to claim 2, characterized in that: In the reaction solution, Zr 4+ , the molar ratio of triethanolamine to citric acid is 1:4:

4.

4. The method for preparing the dimethylamine gas catalytic luminescence sensing material according to claim 1, characterized in that: The zirconium concentration of the reaction solution is 0.5 mol / L-0.8 mol / L; The step of heating the reaction liquid in three stages so that the reaction liquid is converted into sol, gel, and brown precursor powder in sequence includes: heating the reaction liquid at 80°C-100°C for 1h-2h to obtain sol; heating the sol at 110°C-150°C for 1h to obtain gel; heating the gel at 250°C for 0.5h to obtain the brown precursor powder.

5. The method for preparing the dimethylamine gas catalytic luminescence sensing material according to claim 1, characterized in that: The step of calcining the precursor powder and then cooling it naturally comprises: placing the precursor powder in a muffle furnace, calcining it at 450° C.-550° C. for 1 h-3 h, and then cooling it along with the furnace.

6. A dimethylamine gas catalytic luminescence sensing material, characterized in that: The material is prepared by the method for preparing the dimethylamine gas catalytic luminescence sensing material according to any one of claims 1 to 5.

7. A method for preparing a dimethylamine gas catalytic luminescence sensor, characterized in that: The following steps are involved: The dimethylamine gas catalytic luminescent sensing material according to claim 6 is dispersed in a solvent to obtain a suspension; Applying the suspension on the surface of the heating device; drying the heating device; The heating device is installed into the gas chamber, and a photomultiplier tube is assembled to align with the heating device to obtain the dimethylamine gas catalytic luminescence sensor.

8. A dimethylamine gas catalytic luminescence sensor, characterized in that: The dimethylamine gas catalytic luminescence sensor is prepared by the preparation method of the dimethylamine gas catalytic luminescence sensor according to claim 7.

9. A dimethylamine gas detection method applicable to the dimethylamine gas catalytic luminescence sensor according to claim 8, characterized in that: The following steps are involved: Controlling the heating device to generate heat at a constant temperature, wherein the constant temperature is 150° C.-400° C.; Passing sample gas into the gas chamber at a constant flow rate; Acquiring the signal intensity of the light with the wavelength as the detection wavelength collected by the photomultiplier tube; The detection wavelength is 400nm-600nm.

10. The dimethylamine gas detection method according to claim 9, characterized in that: The constant temperature is 210° C.-350° C., the constant flow rate is 300 mL / min-1200 mL / min, and the detection wavelength is 475 nm-555 nm.

Images