Gas detection system based on multifunctional sensing technology and application thereof

Abstract

The invention provides a gas detection system based on a multifunctional sensing technology and application thereof, and belongs to the technical field of sensing. The gas detection system comprises a gas collecting and processing module, a sensing detection module and a signal processing and analyzing module, and the sensing detection module comprises a metal oxide semiconductor sensor unit, a black phosphorus material modified transistor unit and a hollow-core optical fiber enhanced Raman spectrum detection unit. The multi-dimensional gas detection device is used for performing multi-dimensional detection on treated gas, and high-sensitivity and high-selectivity detection on various gases is realized. The gas detection system can accurately judge the type and concentration of gas through cooperative work of all the modules, has the advantages of quick response, real-time monitoring, high stability and reliability and the like, provides a comprehensive solution for gas monitoring, and is suitable for multiple fields such as environment monitoring, industrial safety, medical health or smart home / intelligent traffic and the like.

Description

Technical Field

[0001] The present invention relates to the field of sensing technology, and particularly relates to a gas detection system based on multifunctional sensing technology and its application. Background Art

[0002] With the acceleration of the industrialization process, the importance of gas detection has become increasingly prominent in many fields such as environmental monitoring, industrial production safety, and medical and health. Traditional gas detection methods such as gas chromatography-mass spectrometry (GC-MS) have high detection accuracy, but have disadvantages such as complex equipment, long detection time, and difficulty in realizing on-line real-time monitoring. Raman spectroscopy, as a new gas detection method, has advantages such as no need for gas sample separation and the ability to simultaneously detect multiple components, but its detection sensitivity is limited by the weakness of the Raman scattering effect. In recent years, research on hollow-core fiber enhanced Raman spectroscopy technology has made certain progress. By introducing gas samples into hollow-core fibers and using the fiber's enhancement effect on Raman signals, the sensitivity of gas detection has been improved.

[0003] However, there are still some problems in the existing technology, such as the influence of fiber background noise on the detection results and the relatively long equilibrium time for gas diffusion into the fiber, which limit its popularization in practical applications. Based on this, the present invention combines semiconductor sensors with gas Raman spectroscopy technology to achieve multi-dimensional detection of gases. Summary of the Invention

[0004] Aiming at the above deficiencies of the prior art, the present invention provides a gas detection system based on multifunctional sensing technology and its application. The gas detection system can achieve high-sensitivity and high-selectivity detection of multiple gases, and has good stability and fast response ability, meeting the gas monitoring requirements in various complex environments.

[0005] To achieve the above object, the specific technical solutions of the present invention are as follows:

[0006] In a first aspect, the present invention provides a gas detection system based on multifunctional sensing technology, including: a gas collection and processing module, a sensing and detection module, and a signal processing and analysis module; the gas collection and processing module is connected to the sensing and detection module, and the sensing and detection module is connected to the signal processing and analysis module;

[0007] Among them, the gas collection and processing module is responsible for collecting gas samples from the detection environment and performing necessary preprocessing on the gas; the preprocessing includes but is not limited to dehumidification and / or filtration to ensure that the gas entering the sensing and detection module is pure and stable;

[0008] The sensing and detecting module is used for multi-dimensional detection of the pre-treated gas. The sensing and detecting module includes a metal oxide semiconductor sensor unit, a black phosphorus material modified transistor unit, and a hollow fiber enhanced Raman spectroscopy detection unit; the black phosphorus material modified transistor unit is made of black phosphorus material modified by metal ions;

[0009] The signal processing and analyzing module is used for processing and analyzing the signals output by the sensing and detecting module to determine the type and concentration of the gas.

[0010] The gas detection system of the present invention includes a gas collection and processing module, a sensing and detecting module, and a signal processing and analyzing module. Through the gas collection and processing module, the gas diffusion equilibrium time is shortened. Specifically, the gas collection and processing module of the present invention uses technologies such as dehumidification and / or filtration to pre-treat the gas, ensuring that the gas entering the sensing and detecting module is pure and stable, reducing signal interference caused by humidity or impurities, and thus improving the overall detection efficiency. In the sensing and detecting module, the present invention adopts a multi-channel parallel transmission design, dividing the pre-treated gas into three paths and sending them into the metal oxide semiconductor sensor unit, the black phosphorus material modified transistor unit, and the hollow fiber enhanced Raman spectroscopy detection unit respectively. This shunt design avoids the bottleneck problem of the traditional single channel, significantly shortens the equilibrium time for the gas to diffuse to each sensor, and realizes rapid response. At the same time, each sensing unit has the characteristic of rapid response, can realize real-time monitoring of gas changes, and timely warns of potential safety hazards. Specifically, in the metal oxide semiconductor sensor unit, the present invention uses gallium-doped zinc oxide as the gas-sensitive material. Among them, the gallium / zinc oxide composite material is synthesized by hydrothermal reaction and high-temperature calcination. At the same time, by adjusting the doping ratio of gallium, a uniform porous nanostructure is ensured to avoid the performance degradation of traditional ZnO caused by grain boundary defects; in the subsequent assembly of the sensor, the present invention makes the gallium / zinc oxide composite material form a dense structure through screen printing and high-temperature sintering, further improving the sensitivity and stability of the material. In the black phosphorus material modified transistor unit, the present invention uses chemical doping methods (such as adsorption or deposition) including Ag +Modifying black phosphorus materials (BP) with metal ions enables the metal ions to form stable chemical bonds with phosphorus atoms in the concave regions of black phosphorus. After qualitative analysis through vacuum drying (60 - 80 °C), the hole mobility of the modified black phosphorus materials is increased from 796 cm² / V·s to ≥1500 cm² / V·s, the work function is reduced to 4.24 - 4.54 eV, the antioxidant property is enhanced, and the service life is extended by more than 30%. Meanwhile, the surface adsorption property is enhanced, greatly shortening the interaction time between the gas and the sensor. In addition, the black phosphorus transistors of the present invention are encapsulated in an inert gas environment to prevent black phosphorus from contacting with oxygen / water in the air, and an epoxy resin sealing technology is adopted to enhance physical protection. In the hollow-core fiber enhanced Raman spectroscopy detection unit, the present invention reduces the interference of fiber background noise by controlling the parameters of the hollow-core fiber (such as the aperture matching the gas molecule size) and the CCD and small hole collaborative noise reduction method, increasing the signal-to-noise ratio of the Raman signal to ≥20 dB and the detection limit down to the ppb level. At the same time, the fiber interface is hermetically sealed to prevent gas leakage or external contamination, which not only reduces the need for repeated collection of gas samples but also reduces the impact of background noise on the detection results and improves the detection efficiency.

[0011] Further, the gas detection system further includes a data transmission and display module, which is connected to the signal processing and analysis module and is used for outputting and displaying the detection results.

[0012] Further, the metal oxide semiconductor sensor unit includes a gallium-doped zinc oxide (Ga / ZnO) composite material. The metal oxide semiconductor sensor unit with the Ga / ZnO composite material as the sensitive layer has the characteristics of high response, high selectivity, and low detection limit, and has excellent detection performance for volatile organic compounds such as n-butanol.

[0013] Further, in the Ga / ZnO composite material, the molar ratio of Ga is 0.5% - 5%.

[0014] Further, the Ga / ZnO composite material is prepared by hydrothermal reaction and high-temperature calcination.

[0015] Specifically, the preparation method of the Ga / ZnO composite material includes the following steps:

[0016] (1) Dissolve zinc salt and gallium salt in water, add urea, and mix evenly to obtain a mixed solution;

[0017] (2) React the mixed solution at 160 - 180 °C for 8 - 12 h to obtain a Ga / ZnO precursor;

[0018] (3) Calcinate the Ga / ZnO precursor at 400 - 500 °C for 2 - 3 h to obtain the Ga / ZnO composite material.

[0019] Specifically, the method for preparing the metal oxide semiconductor sensor unit includes the following steps:

[0020] Mix the Ga / ZnO composite material with an organic binder and grind it into a uniform slurry; screen-print the slurry on the surface of the substrate and sinter it at 300-400 °C to form a sensitive layer; weld electrodes on both sides of the sensitive layer to obtain the metal oxide semiconductor sensor unit.

[0021] Further, the metal ions include Ag + ions.

[0022] In the present invention, metal ions including Ag + are introduced onto the surface of the black phosphorus material by a chemical doping method (such as adsorption or deposition) to modify the black phosphorus material, improve its stability and carrier mobility (the hole mobility of the modified black phosphorus material is ≥1500 cm² / V·s), and the doping of Ag + significantly reduces the work function (4.24-4.54 eV), enhances the conductivity, is suitable for fast response scenarios, and is suitable for real-time monitoring.

[0023] Specifically, the method for modifying the black phosphorus material with metal ions includes the following steps:

[0024] Immerse the black phosphorus flakes in a solution containing metal ions, mix them in an inert gas atmosphere for 18-30 h to allow the metal ions to adsorb on the surface of the black phosphorus, and the metal ions preferentially form stable chemical bonds with the phosphorus atoms in the concave regions of the black phosphorus; after washing away the unadsorbed metal ions, vacuum-dry and stabilize the black phosphorus material at 60-80 °C to obtain the metal ion-modified black phosphorus material.

[0025] Further, the hollow-core fiber enhanced Raman spectroscopy detection unit includes a hollow-core fiber, a laser, a spectrometer, and a CCD (Charge Coupled Device) detector; wherein, the hollow-core fiber is used to introduce gas and enhance the Raman signal, the laser is used to provide an excitation light source, and the spectrometer and the CCD detector are used to acquire and analyze the Raman spectrum. The hollow-core fiber enhanced Raman spectroscopy detection unit enhances the Raman signal of the gas through the hollow-core fiber and adopts a CCD and small hole collaborative noise reduction method to improve the signal-to-noise ratio of the Raman spectrum and achieve high-sensitivity detection of the gas.

[0026] Furthermore, the signal processing and analysis module includes a signal acquisition circuit, an amplification circuit, a filtering circuit, and a microprocessor. The microprocessor runs algorithms to analyze the detection data to identify the gas type and concentration. The signal processing and analysis module collects, amplifies, filters, and processes the signals output by the sensing and detection module, and uses corresponding algorithms to analyze and identify the detection data to achieve accurate judgment of the gas type and concentration.

[0027] In a second aspect, the present invention provides an application of the gas detection system in the field of environmental monitoring. The gas detection system is used to monitor pollutants in the atmosphere, providing data support for environmental quality assessment and pollution control. The pollutants include, but are not limited to, volatile organic compounds, carbon dioxide, and carbon monoxide.

[0028] In a third aspect, the present invention provides an application of the gas detection system in the field of industrial safety. The gas detection system is used to monitor the leakage of flammable, explosive, toxic, and harmful gases in the production workshop, giving early warnings and ensuring production safety.

[0029] In a fourth aspect, the present invention provides an application of the gas detection system in the field of medical and health. The gas detection system is used to monitor the gases exhaled by patients, assisting doctors in disease diagnosis and early detection of potential disease risks.

[0030] In a fifth aspect, the present invention provides an application of the gas detection system in the field of smart home or intelligent transportation. The gas detection system is used to monitor indoor air quality or vehicle exhaust emissions, improving the quality of life and the level of traffic environmental protection.

[0031] Compared with the prior art, the advantages of the present invention are as follows:

[0032] 1. High sensitivity and high selectivity

[0033] By integrating multiple sensing technologies, the present invention gives full play to the advantages of each technology and achieves highly sensitive and highly selective detection of multiple gases. For example, the metal oxide semiconductor sensor unit including the Ga / ZnO composite material has a detection response as high as 174.78 to 100 ppm of n-butanol, which is 2.4 times that of ZnO. After modification with black phosphorus materials, the hole mobility of its field-effect transistor is significantly improved, enhancing the gas response ability. The hollow-core fiber enhanced Raman spectroscopy technology further improves the gas Raman signal intensity on the original basis, and the minimum detection limit can reach the ppb level.

[0034] 2. Fast response and real-time monitoring

[0035] The gas detection system of the present invention pre - processes the gas through a gas collection and processing module, shortening the gas diffusion equilibrium time. At the same time, each sensing unit has the characteristic of rapid response, enabling real - time monitoring of gas changes and timely warning of potential safety hazards.

[0036] 3. Good stability and reliability

[0037] The present invention adopts advanced material preparation processes and packaging technologies to ensure the stability and reliability of the system during long - term use. After the black phosphorus material is modified by metal ions, its antioxidant performance is significantly improved, extending the service life of the sensor; the hollow - core fiber enhanced Raman spectroscopy detection unit ensures the accuracy of the detection results through precise fiber parameter control and background noise reduction processing.

[0038] 4. Multifunction and wide application

[0039] This system can detect multiple gases simultaneously, meeting the gas detection requirements in different fields. For example, in environmental monitoring, it can real - time monitor the pollutant concentration in the atmosphere; in industrial production, it can be used to detect the leakage of combustible gases and toxic gases; in the field of medical health, it can analyze exhaled gases to assist in disease diagnosis; in the fields of smart home or intelligent transportation, it can monitor indoor air quality or vehicle exhaust emissions, improving the quality of life and the level of traffic environmental protection. Detailed implementation manners

[0040] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0041] The present invention provides a gas detection system based on multifunctional sensing technology, including: a gas collection and processing module, a sensing and detection module, and a signal processing and analysis module; the gas collection and processing module is connected to the sensing and detection module, and the sensing and detection module is connected to the signal processing and analysis module;

[0042] Among them, the gas collection and processing module is responsible for collecting gas samples from the detection environment and performing necessary pre - processing on the gas; the pre - processing includes but is not limited to dehumidification and / or filtration to ensure that the gas entering the sensing and detection module is pure and stable;

[0043] The sensing and detection module is used for multi - dimensional detection of the pre - processed gas. The sensing and detection module includes a metal oxide semiconductor sensor unit, a black phosphorus material modified transistor unit, and a hollow - core fiber enhanced Raman spectroscopy detection unit; the black phosphorus material modified transistor unit is made of black phosphorus material modified by metal ions;

[0044] The signal processing and analysis module is used to process and analyze the signals output by the sensing and detection module to determine the type and concentration of the gas.

[0045] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0046] Embodiment 1 A gas detection system based on multi-functional sensing technology

[0047] The gas detection system of this embodiment includes: a gas collection and processing module, a sensing and detection module, and a signal processing and analysis module; the gas collection and processing module is connected to the sensing and detection module, and the sensing and detection module is connected to the signal processing and analysis module;

[0048] Among them, the sensing and detection module is used for multi-dimensional detection of the pre-treated gas, and the sensing and detection module includes a metal oxide semiconductor sensor unit, a black phosphorus material modified transistor unit, and a hollow fiber enhanced Raman spectroscopy detection unit.

[0049] The preparation method of the metal oxide semiconductor sensor unit includes the following steps:

[0050] 1. Preparation of gallium-doped zinc oxide (Ga / ZnO) composite material

[0051] Preparation of precursor solution: Dissolve zinc nitrate (Zn(NO3)2·6H2O) and gallium nitrate (Ga(NO3)3·xH2O) in deionized water according to the molar ratio of 1% Ga doping amount, add urea as a precipitating agent, and stir until completely dissolved to obtain a mixed solution;

[0052] Hydrothermal reaction: Transfer the mixed solution to a high-pressure reaction kettle and react at 170 °C for 10 h to generate a Ga / ZnO precursor;

[0053] Calcination treatment: After centrifuging and washing the Ga / ZnO precursor, place it in a muffle furnace and calcine it at 450 °C for 2.5 h to obtain porous Ga / ZnO nanoparticles (particle size of 50 - 100 nm).

[0054] 2. Assembly of the sensor

[0055] Slurry preparation: Mix Ga / ZnO nanoparticles and an organic binder (ethyl cellulose) in a mass ratio of 9:1 and grind them into a uniform slurry;

[0056] Printing and sintering: The slurry was screen-printed on the surface of an Al2O3 ceramic substrate (size 5 mm × 5 mm) to form a sensitive layer with a thickness of about 20 μm, and then sintered at 350 °C for 1 h to remove organic substances;

[0057] Electrode welding: Platinum (Pt) wires were welded on both sides of the sensitive layer as electrodes, and the electrode spacing was 1 mm. Finally, it was encapsulated as a metal oxide semiconductor sensor.

[0058] The preparation method of the black phosphorus material modified transistor unit includes the following steps:

[0059] Black phosphorus flakes (thickness < 10 nm) were obtained from bulk black phosphorus (BP) by mechanical exfoliation method and dispersed in absolute ethanol for standby. The black phosphorus flakes were immersed in a 0.1 M silver nitrate (AgNO3) solution and stirred under nitrogen protection for 24 h to allow Ag + ions to be adsorbed on the surface of black phosphorus, and centrifugally washed 3 times with deionized water to remove unadsorbed Ag + , and dried in vacuum at 60 °C for 12 h to obtain the Ag-BP composite material; the Ag-BP composite material was made into a field effect transistor.

[0060] Example 2 Application of the gas detection system based on multifunctional sensing technology in environmental monitoring

[0061] At urban air quality monitoring stations, it is necessary to monitor various pollutants in the atmosphere such as volatile organic compounds (VOCs), carbon dioxide, carbon monoxide, etc. in real time. The gas detection system of the present invention is installed in the monitoring station, and gas samples are collected from the atmosphere through a gas collection pipeline. The gas sample first enters the gas collection and processing module, and after dehumidification and filtration treatment, it is divided into three paths and sent to the metal oxide semiconductor sensor unit, the black phosphorus material modified transistor unit, and the hollow fiber enhanced Raman spectroscopy detection unit respectively.

[0062] In the metal oxide semiconductor sensor unit, the Ga / ZnO composite material has high response characteristics to VOCs such as n-butanol in the atmosphere. When n-butanol gas is adsorbed on the sensor surface, it will cause a change in the resistance value of the sensor, and the concentration of n-butanol can be determined by measuring the change in the resistance value. Experiments show that the Ga / ZnO composite material of the metal oxide semiconductor sensor unit has a detection limit as low as 0.05 ppm for n-butanol gas at a working temperature of 360 °C, and the response value to 100 ppm of n-butanol gas can reach 174.78, which is much higher than that of traditional ZnO materials (~72.8), and the resistance change rate during long-term use ≤ 3%.

[0063] The black phosphorus material modified transistor unit is mainly used for detecting gases such as carbon dioxide and carbon monoxide in the atmosphere. After being modified by Ag + For the field-effect transistor made of the modified black phosphorus material, its hole mobility is increased from 796 cm² / V·s to 1666 cm² / V·s. When the target gas adsorbs on the black phosphorus surface, it will change the electrical properties of the material, thus affecting the output current of the transistor. By monitoring the output current, highly sensitive detection of gases such as carbon dioxide and carbon monoxide can be achieved. Among them, the detection limits for carbon dioxide and carbon monoxide are as low as 10 ppb.

[0064] Black phosphorus materials modified by different metal ions have different properties. The adsorption properties of black phosphorus materials modified by different metal ions for CO and C2H4 are shown in Table 1. The unmodified black phosphorus material by metal ions cannot effectively adsorb thermal runaway gases, with a low adsorption energy (Eads) (<0.3 eV) and negligible charge transfer (ΔQ). Au 3+ Compared with the unmodified black phosphorus material, the modified black phosphorus material shows selective adsorption for CO and C2H4, with a relatively high adsorption energy (>1.0 eV), mainly chemical adsorption; the work function (WF) is significantly reduced and the conductivity is enhanced. Pt 4+ The modified black phosphorus material has a strong binding energy (Eb) and high stability; the adsorption energy for CO and C2H4 is extremely high (>1.5 eV), but the recovery time is too long and auxiliary desorption means (such as ultraviolet light) are required. Pd 2+ The modified black phosphorus material has a relatively high adsorption energy for CO and C2H4 (>1.1 eV), and the change in work function is significantly different (the conductivity decreases after CO adsorption and increases after C2H4 adsorption). And Ag + The modified black phosphorus material shows selective adsorption for CO and C2H4, with a relatively high adsorption energy (>0.8 eV); the recovery time is short (in minutes), which is very suitable for real-time monitoring.

[0065] Table 1: Adsorption properties of black phosphorus materials modified by different metal ions for CO and C2H4

[0066]

[0067] The hollow-core fiber enhanced Raman spectroscopy detection unit uses Raman spectroscopy technology to analyze various gases in the atmosphere. The gas sample is introduced into the hollow-core fiber and Raman scattering occurs under laser irradiation. By using the CCD and small hole collaborative noise reduction method, the fiber background noise is effectively filtered, and the signal-to-noise ratio of the Raman spectrum is improved. The experimental results show that the detection limits of this unit for gases such as carbon dioxide and methane can reach the ppb level.

[0068] The signal processing and analysis module collects and processes the signals output by each sensing unit, analyzes the detection data through algorithms, and realizes the accurate judgment of the gas type and concentration. The processed data is transmitted and displayed on the terminal device of the environmental monitoring center through the data transmission and display module, real-time displaying the concentration changes of various pollutants in the atmosphere, and can generate historical data reports, providing a scientific basis for environmental quality assessment and pollution control.

[0069] Embodiment 3 Application of the Gas Detection System Based on Multifunctional Sensing Technology in the Field of Industrial Safety

[0070] In the production workshops of chemical production enterprises, there are risks of leakage of various flammable, explosive, toxic and harmful gases. The gas detection system of the present invention is installed at key positions in the workshop to monitor the gas components in the air in real time. Once a gas leak occurs, the system can quickly issue an alarm and transmit the detection data to the safety monitoring center for timely emergency measures.

[0071] In this application scenario, the metal oxide semiconductor sensor unit has a high selective detection ability for VOCs such as organic solvents that may leak in the workshop, such as toluene and xylene, and the detection limit for toluene, xylene and other VOCs is as low as 0.1 ppm. The black phosphorus material modified transistor unit is used to monitor toxic gases such as hydrogen sulfide and ammonia. The hollow fiber enhanced Raman spectroscopy detection unit can analyze multiple gases simultaneously, and can accurately identify the concentration of each gas even in the presence of complex gas mixtures.

[0072] Through the collaborative work of each sensing unit, the gas detection system can quickly respond in the initial stage of gas leakage and accurately judge the type and concentration of the leaked gas, providing strong technical support for ensuring production safety and personnel health.

[0073] Embodiment 4 Application of the Gas Detection System Based on Multifunctional Sensing Technology in the Field of Medical and Health

[0074] In medical institutions, the analysis of patients' exhaled gases can assist doctors in disease diagnosis. For example, the acetone content in the exhaled gases of diabetic patients is relatively high, and the content of specific VOCs in the exhaled gases of some cancer patients also changes. The gas detection system of the present invention has a detection limit for patients' exhaled gases such as acetone as low as 5 ppb, and can be applied to the respiratory department and physical examination center of hospitals for collecting and analyzing the exhaled gases of patients.

[0075] The gas exhaled by the patient enters the gas detection system of the present invention through the gas collection device. After being pre-treated by the gas collection and processing module, it is detected by each sensing unit of the sensing and detection module. The metal oxide semiconductor sensor unit and the black phosphorus material modified transistor unit can screen and preliminarily detect specific biomarkers in the gas. The hollow-core fiber enhanced Raman spectroscopy detection unit provides more accurate gas composition analysis, which helps to discover trace abnormal components in the gas.

[0076] Through the comprehensive analysis of the detection data, doctors can more accurately understand the respiratory health status of patients, detect potential disease risks at an early stage, and provide important reference basis for clinical diagnosis and treatment.

[0077] In summary, the gas detection system of the present invention uses a sensing and detection module including a metal oxide semiconductor sensor unit, a black phosphorus material modified transistor unit, and a hollow-core fiber enhanced Raman spectroscopy detection unit to perform multi-dimensional detection on the processed gas, achieving high-sensitivity and high-selectivity detection of various gases. Through the collaborative work of each module, the gas detection system of the present invention can accurately judge the type and concentration of gases, and has advantages such as fast response, real-time monitoring, high stability, and reliability. It provides a comprehensive solution for gas monitoring and is applicable to multiple fields such as environmental monitoring, industrial safety, medical health, or smart home / smart transportation.

[0078] The above specific embodiments have described the implementation of the present invention in detail. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple variations all belong to the protection scope of the present invention.

Claims

1. A gas detection system based on multifunctional sensing technology, characterized in that: include: Gas collection and processing module, sensor detection module and signal processing and analysis module; The gas collection and processing module is connected to the sensor detection module, and the sensor detection module is connected to the signal processing and analysis module; The gas collection and processing module is responsible for collecting gas samples from the detection environment and processing the gas; The sensing detection module is used to perform multi-dimensional detection on the treated gas, and the sensing detection module includes a metal oxide semiconductor sensor unit, a black phosphorus material modified transistor unit and a hollow core fiber enhanced Raman spectroscopy detection unit; the black phosphorus material modified transistor unit is made of black phosphorus material modified by metal ions; The signal processing and analysis module is used to process and analyze the signal output by the sensor detection module.

2. A gas detection system based on multifunctional sensing technology according to claim 1, characterized in that: The metal ions include Ag + ion.

3. A gas detection system based on multifunctional sensing technology according to claim 1, characterized in that: The method for modifying black phosphorus material with metal ions comprises the following steps: immersing black phosphorus flakes in a solution containing metal ions, mixing for 18 to 30 hours under an inert gas atmosphere to allow the metal ions to adsorb on the surface of black phosphorus, and drying and characterizing to obtain a black phosphorus material modified with metal ions.

4. A gas detection system based on multifunctional sensing technology according to claim 1, characterized in that: The metal oxide semiconductor sensor unit includes a gallium-doped zinc oxide composite material.

5. A gas detection system based on multifunctional sensing technology according to claim 4, characterized in that: In the gallium-doped zinc oxide composite material, the molar proportion of gallium is 0.5% to 5%.

6. A gas detection system based on multifunctional sensing technology according to claim 4, characterized in that: The gallium-doped zinc oxide composite material is prepared by hydrothermal reaction and high-temperature calcination.

7. A gas detection system based on multifunctional sensing technology according to claim 6, characterized in that: The preparation method of the gallium-doped zinc oxide composite material comprises the following steps: (1) dissolving zinc salt and gallium salt in water, adding urea, and mixing well to obtain a mixed solution; (2) reacting the mixed solution at 160-180 °C for 8-12 h to obtain a Ga / ZnO precursor; (3) Calcine the Ga / ZnO precursor at 400~500 ℃ for 2~3 h to obtain a Ga / ZnO composite material.

8. A gas detection system based on multifunctional sensing technology according to claim 1, characterized in that: The hollow-core fiber enhanced Raman spectrum detection unit comprises a hollow-core fiber, a laser, a spectrometer and a CCD detector; wherein the hollow-core fiber is used to introduce gas and enhance Raman signals, the laser is used to provide an excitation light source, and the spectrometer and CCD detector are used to acquire and analyze Raman spectra.

9. A gas detection system based on multifunctional sensing technology according to claim 1, characterized in that: The signal processing and analysis module includes a signal acquisition circuit, an amplification circuit, a filtering circuit and a microprocessor. The microprocessor analyzes the detection data by running an algorithm to identify the type and concentration of the gas.

10. Application of the gas detection system according to any one of claims 1 to 9 in the fields of environmental monitoring, industrial safety, medical health, or smart home / smart transportation.

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