Highly Sensitive Low-Temperature Sensing Metal Oxide Semiconductor Materials, Their Composites and Applications

Abstract

The present invention discloses a highly sensitive low-temperature sensitive metal oxide semiconductor material, its composite, and applications. The semiconductor material uses silica spheres as a template and metal oxides as a precursor. Through the template self-assembly method, and then removing the template, a highly sensitive low-temperature sensitive metal oxide semiconductor material is prepared. The unique structure of the metal oxide composite material of this material can achieve highly sensitive monitoring of specific components in exhaled breath at room temperature, can effectively reduce the gas-sensitive sensing temperature of the material, without additional heating, and improve the sensitivity. The gas-sensitive sensor prepared using this material can be integrated into a medical mask for exhaled breath monitoring, and is used for monitoring and warning of the occurrence and observation of major diseases, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the field of disease diagnosis materials, in particular to a highly sensitive low-temperature sensing metal oxide semiconductor material, and also to a composite containing the highly sensitive low-temperature sensing metal oxide semiconductor material and its application. Background Art

[0002] Exhaled breath detection is the detection of volatile organic compounds (VOC) in exhaled breath. In the field of health, exhaled breath detection can help people complete more accurate and efficient life health and safety monitoring. Many medical studies now show that human exhaled breath contains a lot of health information. People can not only monitor whether their breath is fresh through gas sensors, but also track human health and diagnose diseases early by detecting the content of special gases in exhaled breath. Exhaled breath detection is a non-invasive, new screening method for medical diagnosis, which can be used to diagnose a variety of diseases. For example, the human body usually consumes carbohydrates, sugars and fats during exercise, and acetone, a byproduct of burning fat, is excreted from the body through breathing. The detection of acetone, hydrogen sulfide, ammonia, nitric oxide and other gases in exhaled breath combined with wearable devices can realize real-time monitoring of sports health, which is conducive to the development of health monitoring product systems. Medical research has shown that the acetone gas content exhaled by diabetics is strongly correlated with their blood sugar concentration, and their blood sugar concentration can be judged by detecting the acetone concentration in the patient's exhaled breath. At present, gas chromatography-mass spectrometry is considered to be a feasible detection technology for clinical detection of VOCs. However, this technology is difficult to promote and requires expensive instruments, strict sample pretreatment processes, and specialized operators. Therefore, people have explored and studied new methods and technologies. Among the many methods, metal oxide-based gas sensing technology has become a research hotspot due to its advantages of low power consumption, small size, simple equipment, easy use, high sensitivity, fast response, and low price. It is expected to become a substitute for chromatography-mass spectrometry technology.

[0003] Acetone is a biomarker for diabetes in exhaled breath. According to the latest global diabetes map (IDF Diabetes Atlas, 9th edition) released by the International Diabetes Federation (IDF): Approximately 463 million adults worldwide had diabetes in 2019, an increase of 38 million compared to 2017. The acetone content in the exhaled breath of normal people is 300 - 900 ppb, while the acetone content in the exhaled breath of diabetes patients is greater than or equal to 1.8 ppm. The exhaled nitric oxide content of non-smoking normal adults is 6.1 - 41.0 ppb. In order to accurately determine the content of disease markers in exhaled gas, gas-sensitive sensing materials with higher sensitivity need to be found. Currently, the main factors restricting the development of metal oxide semiconductor gas sensors are high working temperature, insufficient sensitivity, and poor moisture resistance. Therefore, how to improve metal oxide semiconductor materials to achieve high-sensitivity low-temperature sensing performance has become a research hotspot. Summary of the Invention

[0004] In view of this, one of the purposes of the present invention is to provide a highly sensitive low-temperature sensing metal oxide semiconductor material, which has a unique structure and high sensitivity at low temperature. The second purpose of the present invention is to provide a gas-sensitive sensing composite material prepared by using the highly sensitive low-temperature sensing metal oxide semiconductor material. The third purpose of the present invention is to provide the application of the gas-sensitive sensing composite material in the preparation of a gas sensor for detecting disease judgment indicators. The fourth purpose of the present invention is to provide a gas-sensitive sensing device for exhaled breath detection.

[0005] To achieve the above purposes, the present invention provides the following technical solutions:

[0006] 1. A highly sensitive low-temperature sensing metal oxide semiconductor material, wherein the semiconductor material uses silica spheres as a template and metal oxides as a precursor, and through a template self-assembly method, and then removes the template to obtain a highly sensitive low-temperature sensing metal oxide semiconductor material.

[0007] In the present invention, the metal oxide is preferably but not limited to Co 3 O 4 , CuO, NiO, ZnO 2 , SnO 2 , or Fe 2 O 3 , and other semiconductor materials can also be selected.

[0008] Preferably, the morphology of the highly sensitive low-temperature sensing metal oxide semiconductor material is a hollow porous sphere, a nanocube, a 2D porous sheet, a nanowire, or a nanoflower.

[0009] Preferably, in the present invention, silica spheres are used as templates and cobalt ferrite gold is used as a precursor. A spherical composite material is obtained by self-assembly at 95 °C for 6-12 h, and the template is removed after calcination at 300-500 °C to obtain a hollow porous metal oxide material; more preferably, the optimal calcination temperature of the metal oxide is 400 °C and the time is 4 h.

[0010] 2. A gas-sensitive sensing composite material is prepared by using the highly sensitive low-temperature sensitive metal oxide semiconductor material. The composite material is prepared by compounding the metal oxide semiconductor material with graphene, noble metal, black phosphorus, MOF, MXene, carbon nanotube or metal oxide.

[0011] In the present invention, the compounding method is hydrothermal method, high-temperature calcination method, freeze-drying method, ball milling method, wet chemical method or reflux method.

[0012] 3. Application of the gas-sensitive sensing composite material in the preparation of a gas sensor for detecting disease judgment indexes.

[0013] In the present invention, the disease is not limited to diabetes or asthma, and may also be other diseases with exhaled component detection markers.

[0014] In the present invention, the judgment indexes are preferably but not limited to acetone, nitric oxide, hydrogen sulfide or ammonia.

[0015] 4. A gas-sensitive sensing device for exhaled breath detection. The gas-sensitive sensing device contains a gas sensor, and the gas sensor is prepared by drop-coating, printing or spin-coating the gas-sensitive sensing composite material on a detection probe.

[0016] In the present invention, the gas-sensitive sensing device is a mask, a mobile phone, a household sensor, a ventilator, a drone or a robot.

[0017] Preferably, the gas-sensitive sensing device is a mask, and its structure is that a fourth inner spunbond non-woven fabric is added between the first layer and the second layer from the inside to the outside of the three-layer structure of a medical mask. The gas sensor is placed between the first layer and the second layer, and the gas sensor monitors specific components in the exhaled breath, and the electrical signal is detected by a smart device.

[0018] The beneficial effects of the present invention are as follows: The present invention discloses a highly sensitive low-temperature sensitive metal oxide semiconductor material. The metal oxide with a unique structure can effectively reduce the gas-sensitive sensing temperature of the material and improve the sensitivity. The gas sensor prepared by using this material can be integrated into a medical mask for exhaled breath monitoring, and is used for monitoring and warning the occurrence and observation of major diseases. The unique structure metal oxide composite material of the present invention can realize high-sensitive monitoring of specific components in exhaled breath at room temperature without additional heating. Description of the Drawings

[0019] To make the objectives, technical solutions and beneficial effects of the present invention clearer, the present invention provides the following attached drawings for description:

[0020] Figure 1 It is a diagram of a hollow porous metal oxide material composite;

[0021] Figure 2 It is the comparison result of the room temperature gas sensing performance between the metal oxide material and the composite material (A: metal oxide material; B: composite material);

[0022] Figure 3 It is a schematic diagram of the exhaled breath monitoring of the gas sensing device. Specific Embodiments

[0023] The following further describes the present invention in conjunction with the attached drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the exemplified embodiments are not intended to limit the present invention.

[0024] Example 1. Preparation Method of Metal Oxide Semiconductor Material with High-Sensitivity Low-Temperature Sensing Performance

[0025] The preparation method of the metal oxide semiconductor material with high-sensitivity low-temperature sensing performance is as follows: Using silica spheres as the template and metal oxides as the precursors, spherical composites are obtained through self-assembly at 95°C for 6 - 12 hours, and after calcination at 300 - 500°C, the template is removed to obtain a hollow porous metal oxide material.

[0026] In the present invention, the metal oxides Co 3 O 4 , CuO, NiO, ZnO 2 , SnO 2 , or Fe 2 O 3 can also be other semiconductors.

[0027] Taking Co 3 O 4 as the oxide, spherical composites are obtained through self-assembly at 95°C for 6 - 12 hours, and after calcination at 400°C for 4 hours, the template is removed to obtain a hollow porous metal oxide material.

[0028] The obtained hollow porous metal oxide material is in the spherical structure as above, and the results show that the hollow porous metal oxide material is a hollow porous sphere with controllable shell thickness, sphere size and pore structure. Structures made of other materials such as nanocubes, 2D porous sheets, nanowires or nanoflowers can also achieve the purpose of the invention. Figure 1

[0029] Example 2. Preparation of Gas Sensing Composite Material ​

[0030] Scheme 1: Then, the obtained hollow porous metal oxide material is compounded with the 2D material graphene by room-temperature self-assembly or hydrothermal method.

[0031] Scheme 2: Then, the obtained hollow porous metal oxide material is compounded with the 2D material MXene by room-temperature self-assembly or hydrothermal method.

[0032] Scheme 3: Then, the obtained hollow porous metal oxide material is compounded with the 2D material black phosphorus by room-temperature self-assembly or hydrothermal method.

[0033] Scheme 4: Then, the obtained hollow porous metal oxide material is compounded with the noble metal Pd by room-temperature self-assembly or hydrothermal method.

[0034] Scheme 5: Then, the obtained hollow porous metal oxide material is compounded with the noble metal Au by room-temperature self-assembly or hydrothermal method.

[0035] Scheme 6: Then, the obtained hollow porous metal oxide material is compounded with the noble metal Pt by room-temperature self-assembly or hydrothermal method.

[0036] Scheme 7: Then, the obtained hollow porous metal oxide material is compounded with carbon nanotubes by room-temperature self-assembly or hydrothermal method.

[0037] Scheme 8: Then, the obtained hollow porous metal oxide material is compounded with MOF by room-temperature self-assembly or hydrothermal method.

[0038] In this embodiment, the hollow porous metal oxide material can be compounded with one or two combinations of 2D materials (such as graphene), noble metals, carbon nanotubes, MOF, and polymers. The compounding methods include hydrothermal method, high-temperature calcination method, freeze-drying method, ball milling method, wet chemical method, reflux method, etc.

[0039] The structure of the composite material is as Figure 1 shown. The results show that the hollow porous metal oxide material is firmly compounded on the 2D material.

[0040] Example 3: Detection of acetone by gas-sensitive sensing composite material

[0041] The prepared metal oxide material and composite material are applied to the detection probe by drop coating, printing, or spin coating, and the acetone gas-sensitive sensing performance experiments are carried out at room temperature respectively. The results are as Figure 2 shown. The results show that the composite material can meet the requirements of sensing acetone at room temperature and has high sensitivity.

[0042] Similarly, the same principle can be used to detect other exhaled component detection markers, such as nitric oxide, hydrogen sulfide, or ammonia.

[0043] Example 4: Gas-sensitive sensing device for exhaled breath detection

[0044] The prepared composite material is used to prepare a gas sensor, and the structure is as Figure 3 shown. A fourth inner spunbond non-woven fabric is added between the first layer and the second layer from the inside to the outside in the three-layer structure of the medical mask. The first layer of spunbond non-woven fabric plays a role in isolating water vapor and initially separating exhaled breath. The gas sensor is placed in the first and second interlayers. The role of the first layer is to initially separate exhaled breath. The gas sensor monitors specific components in exhaled breath, and through signal changes such as resistance-time, current-time, potential-time, etc., an early warning is given by intelligent devices such as mobile phones or wearable devices. When it exceeds or is lower than the normal level, an alarm signal is sent. Using this device can not only play a role in isolating foreign germs but also play a role in self-monitoring.

[0045] In the present invention, it can also be directly used in mobile phones, household sensors, ventilators, drones or robots for real-time monitoring.

[0046] The above-described embodiments are only preferred embodiments cited to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A highly sensitive low-temperature sensitive metal oxide semiconductor material, characterized in that: The semiconductor material uses silica spheres as a template and metal oxides as a precursor, and is self-assembled at a temperature of 80°C - 95°C for 2 - 16 h to obtain a spherical composite material. After calcination at 300 - 500°C, the template is removed to prepare a highly sensitive low-temperature sensitive metal oxide semiconductor material; The metal oxide is Co 3 O 4 , CuO, NiO, ZnO 2 , SnO 2 or Fe 2 O 3 , or a mixture thereof; The morphology of the highly sensitive low-temperature sensitive metal oxide semiconductor material is a nanostructured hollow porous sphere, nanocube, 2D porous sheet, nanowire or nanoflower.

2. The highly sensitive low-temperature sensitive metal oxide semiconductor material according to claim 1, characterized in that: Silica spheres are used as a template and cobalt ferrite is used as a precursor. The spherical composite material is obtained by self-assembly at a temperature of 80°C - 95°C for 2 - 16 h. After calcination at 300 - 500°C, the template is removed to obtain a hollow porous metal oxide material.

3. Using the highly sensitive low-temperature sensitive metal oxide semiconductor material according to any one of claims 1 to 2 to prepare a gas-sensitive sensing composite material, characterized in that: The composite material is prepared by compounding a metal oxide semiconductor material with graphene, noble metal, black phosphorus, MOF, MXene, carbon nanotube or metal oxide.

4. The gas-sensitive sensing composite material according to claim 3, characterized in that: The compounding method is hydrothermal method, high-temperature calcination method, freeze-drying method, ball milling method, wet chemical method or reflux method.

5. Application of the gas-sensitive sensing composite material according to claim 3 or 4 in the preparation of a gas sensor for detecting disease judgment indicators.

6. The application according to claim 5, characterized in that: The disease is diabetes or asthma.

7. The application according to claim 5, characterized in that: The judgment indicators are acetone, nitric oxide, hydrogen sulfide or ammonia.

8. A gas-sensitive sensing device for exhaled breath detection, characterized in that, The gas-sensitive sensing device contains a gas sensor, and the gas sensor is prepared by drop-coating, printing or spin-coating the gas-sensitive sensing composite material according to claim 3 or 4 on a detection probe.

9. The gas-sensitive sensing device according to claim 8, characterized in that: The gas-sensitive sensing device is a mask, mobile phone, household sensor, ventilator, drone, robot, or wearable device.

10. The gas-sensitive sensing device according to claim 8, characterized in that: The gas-sensitive sensing device is a mask, and its structure is that a fourth inner layer of spunbond non-woven fabric is added between the first layer and the second layer from the inside to the outside in the three-layer structure of a medical mask. The gas sensor is placed between the first layer and the second layer, and the gas sensor monitors specific components in the exhaled breath and detects the electrical signal through a smart device.

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