CN116879248A - Dual-wavelength laser-induced fluorescence light path system for monitoring biological aerosol - Google Patents
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6402—Atomic fluorescence; Laser induced fluorescence
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/645—Specially adapted constructive features of fluorimeters
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6486—Measuring fluorescence of biological material, e.g. DNA, RNA, cells
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N2021/6417—Spectrofluorimetric devices
- G01N2021/6419—Excitation at two or more wavelengths
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Abstract
The invention provides a dual-wavelength laser-induced fluorescence light path system for monitoring bioaerosols, which uses two lasers with different wavelengths to excite aerosol particles to generate fluorescence, and uses independent red laser to irradiate the aerosol particles to determine the particle size of the aerosol particles, so that the dual-wavelength laser-induced fluorescence light path system can be used for distinguishing different aerosol particles, and solves the problem of difficult anti-interference existing in bioaerosols monitoring; the light path system uses the beam splitting filter to enable laser beams with different wavelengths to be coplanar and parallel, and the light path in the detection cavity is simple; the scattered light/fluorescence receiving light path is perpendicular to the laser irradiation light path, a dichroic beam-splitting filter and a wave-pass filter are used for separating and collecting a plurality of scattered light/fluorescence intensity spectrum signals, and the excitation-receiving light path is concise; the whole light path system is L-shaped, does not use a reverse fluorescence receiving light path, reduces the holes of the receiving light path on the detection cavity, effectively reduces the volume of the detection cavity, reduces the interference of stray light, and simultaneously improves the overall structural strength of the system.
Description
Technical Field
The invention belongs to the technical field of biological detection, and particularly relates to a dual-wavelength laser-induced fluorescence light path system for exciting biological aerosol particles to generate fluorescence and distinguishing and detecting the concentration of the biological aerosol particles.
Background
Bioaerosols are important components of atmospheric aerosols, and are solid or liquid particles containing biological activities such as microorganisms or biomacromolecules. The bioaerosol particles comprise bacteria, fungi, viruses, chlamydia, mycoplasma, rickettsia, dust mites, pollen, spores, animal and plant proteins, various mycotoxins, fragments and secretions thereof, and the like, and the particle size is in the range of 0.01-100 mu m. The aerosol spreads hundreds of harmful pathogenic microorganisms, which can cause a wide range of pollution in a short time. Therefore, the monitoring of the biological aerosol is enhanced, and the method has important significance for public safety, medical and health and environmental monitoring.
Currently, the real-time online detection technology of bioaerosols is mainly Laser Induced Fluorescence (LIF). The biological organic substances such as proteins, viruses, bacteria and the like contained in the biological aerosol particles have fluorescent groups, and can generate fluorescence under the excitation of laser with corresponding wavelength. The fluorescence spectra of these biological substances vary significantly, such as the typical bioluminescent molecule tryptophan (excitation wavelength lambda ex =280 nm), riboflavin (λ ex =450 nm), coenzyme-Nicotinamide Adenine Dinucleotide (NADH) (λ) ex =350 nm), etc., having different excitation-emission matrices, so that it is possible to determine whether or not it is a bioaerosol particle by detecting fluorescence generated therebyParticulate matter and its concentration. LIF has the advantages of high detection sensitivity, simple and convenient operation, large detection range and the like. However, not only the bioaerosol but also other substances such as Polycyclic Aromatic Hydrocarbons (PAH) and humins can be excited to fluoresce in the atmosphere. Thus, LIF-based detection instruments can produce false positives when bioaerosol particles and non-biological fluorescent particles are detected simultaneously.
Currently commercial aerosol particle sensors/particle counters mostly use single wavelength lasers for LIF, e.g. ultraviolet aerodynamic particle sizer (UV-APS, model TSI 3314) manufactured by TSI company in the united states uses a 30mW 680nm laser to irradiate the aerosol sample gas stream to determine its particle size, followed by a 80mW 5khz 355nm pulsed laser to excite the biological particles to fluoresce and detect the biological aerosol particle concentration; a TSI 3317 type fluorescent aerosol particle sensor (flag) uses a 30mW 405nm laser to illuminate the aerosol particles to produce both scattered light and fluorescence. The instrument generally only provides results of total number of aerosol particles, fluorescent particle number and the like, the available aerosol particle information is less, non-biological fluorescent particle interference is not easy to be eliminated, and the fluorescent particle type identification is difficult.
The biological aerosol analyzer WIBS NEO produced by the American DMT company uses 635nm laser to measure the particle size and asymmetry factor, uses 280nm and 370nm laser to perform LIF, can detect fluorescence emission in the wave bands of 310-400 nm and 420-650 nm, detects and distinguishes aerosol particles through different excitation-emission matrixes, and improves the sensitivity and resolution of fluorescence detection. However, compared with a single-wavelength LIF aerosol detection device, the existing dual-laser device is used as an excitation light source of LIF to perform biological aerosol detection, which has the defects of large volume, high price and the like of an instrument, especially the dual-wavelength LIF detection device has a complex detection light path, such as the WIBS NEO irradiates 280nm and 370nm lasers to the same place of aerosol particle airflow in a focusing and crossing way, while the same particle can be excited to test fluorescence in different wave bands, scattered light generated by the irradiation of the biological aerosol particles with the excitation light in different wave bands may cause saturation on fluorescence detectors in different wave bands, and the installation positions of the fluorescence detectors and the excitation light path in a detection cavity have the problem of space obstruction. In order to solve the difficulty in the design and construction of the optical path for dual-wavelength LIF aerosol detection, the invention provides an optical path system for dual-wavelength laser-induced fluorescence detection of biological aerosol.
Disclosure of Invention
First, the technical problem to be solved
The invention provides a dual-wavelength laser-induced fluorescence light path system for monitoring biological aerosol, which aims to solve the technical problems of poor anti-interference performance of single-wavelength LIF detection aerosol, complex light path, large volume and the like of the current dual-wavelength LIF aerosol detection device.
(II) technical scheme
In order to solve the technical problems, the invention provides a dual-wavelength laser-induced fluorescence optical path system for monitoring bioaerosol, which comprises a laser unit (1), a detection cavity (2) and a spectrum receiving unit (3) which are connected in sequence; the aerosol particles contained in the aerosol airflow (2-3) in the detection cavity (2) are irradiated by laser emitted by the laser unit (1) and generate scattered light and fluorescence, and the scattered light and the fluorescence are detected by the spectrum receiving unit (3) and subjected to subsequent data acquisition and photoelectric signal processing.
Further, the laser emission direction of the laser unit (1) is perpendicular to the scattered light and fluorescence receiving direction of the spectrum receiving unit (3).
Further, the laser unit (1) comprises a scattered light laser (1-1-1), a first fluorescent laser (1-1-2), a second fluorescent laser (1-1-3), a first dichroic beam-splitting filter (1-2-1), a second dichroic beam-splitting filter (1-2-2), a first collimating mirror (1-3-1), a second collimating mirror (1-3-2), a third collimating mirror (1-3-3) and a focusing mirror (1-4); wherein, the liquid crystal display device comprises a liquid crystal display device,
the scattered light laser (1-1-1) is arranged in the laser unit (1), and laser emitted by the scattered light laser (1-1-1) sequentially irradiates into the detection cavity (2) through the first collimating mirror (1-3-1), the first dichroic beam-splitting filter (1-2-1), the second dichroic beam-splitting filter (1-2-2) and the focusing mirror (1-4);
the first fluorescent lasers (1-1-2) and the second fluorescent lasers (1-1-3) are arranged in the laser unit (1) at parallel intervals, and laser emitted by the first fluorescent lasers (1-1-2) is reflected by the first dichroic beam-splitting filter (1-2-1) after passing through the second collimating mirror (1-3-2) and then irradiates into the detection cavity (2) through the second dichroic beam-splitting filter (1-2-2) and the focusing mirror (1-4); the laser emitted by the second fluorescent laser (1-1-3) is reflected by the second dichroic beam-splitting filter (1-2-2) after passing through the third collimating mirror (1-3-3), and then is irradiated into the detection cavity (2) through the focusing mirror (1-4);
three laser beams emitted by the scattered light laser (1-1-1), the first fluorescent laser (1-1-2) and the second fluorescent laser (1-1-3) are regulated by the first dichroic beam-splitting filter (1-2-1), the second dichroic beam-splitting filter (1-2-2) and the focusing mirror (1-4) to form three laser beams which are coplanar and parallel and irradiate into the detection cavity (2) at the same time, and the three laser beams form focusing light spots at the aerosol airflow (2-3) to excite aerosol particles to generate fluorescence and scattered light.
Further, the detection cavity (2) comprises an aerosol sample injection nozzle (2-1), an aerosol exhaust port (2-2) and an extinction device (2-4); the aerosol sampling nozzle (2-1) is arranged at the right center of the top of the detection cavity (2), and the aerosol exhaust port (2-2) is arranged at the right center of the bottom of the detection cavity (2) and vertically corresponds to the aerosol sampling nozzle (2-1); three coplanar parallel lasers emitted by the laser unit (1) sequentially pass through aerosol airflow (2-3) emitted by the aerosol sample injection nozzle (2-1), and scattered light and fluorescence are generated after aerosol particles are irradiated; the rest light of the laser emitted by the laser unit (1) after exciting aerosol particles is absorbed by the extinction device (2-4), so that the interference of the excitation light on fluorescence is avoided; the aerosol air flow (2-3) is pumped out of the detection cavity (2) through the aerosol exhaust port (2-2).
Further, the spectrum receiving unit (3) comprises a third dichroic beam-splitting filter (3-1-1), a fourth dichroic beam-splitting filter (3-1-2), a first long-wave pass filter (3-2-1), a second long-wave pass filter (3-2-2), a first photomultiplier (3-3-1), a second photomultiplier (3-3-2), a third photomultiplier (3-3-3) and a collimator (3-4); wherein, the liquid crystal display device comprises a liquid crystal display device,
scattered light generated by laser irradiation of the scattered light laser (1-1-1) on aerosol particles sequentially passes through a collimating lens (3-4), a third dichroic beam-splitting filter (3-1-1) and a fourth dichroic beam-splitting filter (3-1-2) and then is received by a first photomultiplier (3-3-1), and a scattered light signal of the aerosol particles is obtained after photoelectric conversion and data processing;
the fluorescence generated by the laser emitted by the first fluorescent laser (1-1-2) irradiating the aerosol particles is irradiated to the third dichroic beam-splitting filter (3-1-1) through the collimating mirror (3-4), the fluorescence with the wavelength larger than that of the transmission band of the third dichroic beam-splitting filter (3-1-1) passes through the third dichroic beam-splitting filter (3-1-1) and irradiates to the fourth dichroic beam-splitting filter (3-1-2), wherein the fluorescence with the wavelength smaller than that of the reflection band of the fourth dichroic beam-splitting filter (3-1-2) is reflected to the first wavelength-pass filter (3-2-1), the filtered fluorescence is irradiated to the second photomultiplier (3-3-2) through the first wavelength-pass filter (3-2-1) and received, and a fluorescence signal generated by the laser emitted by the first fluorescent laser (1-1-2) irradiating the aerosol particles is obtained after photoelectric conversion and data processing;
fluorescence generated by the laser emitted by the second fluorescent laser (1-1-3) irradiating aerosol particles is irradiated to the third dichroic beam-splitting filter (3-1-1) through the collimating mirror (3-4), fluorescence with the wavelength smaller than that of the reflection band of the third dichroic beam-splitting filter (3-1-1) is reflected to the second long-wave pass filter (3-2-2), and the filtered fluorescence is irradiated to the third photomultiplier (3-3-3) through the second long-wave pass filter (3-2-2) and received; fluorescence having a wavelength greater than that of the transmission band of the third dichroic beam splitter filter (3-1-1) is irradiated onto the fourth dichroic beam splitter filter (3-1-2) through the third dichroic beam splitter filter (3-1-1), wherein fluorescence having a wavelength less than that of the reflection band of the fourth dichroic beam splitter filter (3-1-2) is reflected onto the first long-wavelength pass filter (3-2-1), and the filtered fluorescence is irradiated onto the second photomultiplier (3-3-2) through the first long-wavelength pass filter (3-2-1) and received; and obtaining a fluorescence signal generated by irradiating aerosol particles with laser light emitted by the second fluorescence laser (1-1-3) after photoelectric conversion and data processing.
Further, the laser wavelength emitted by the scattered light laser (1-1-1) is 650nm; the wavelength of laser emitted by the first fluorescent laser (1-1-2) is 405nm; the laser wavelength of the second fluorescent laser (1-1-3) is 360nm.
Further, the first dichroic beam-splitting filter (1-2-1), the second dichroic beam-splitting filter (1-2-2), the third dichroic beam-splitting filter (3-1-1) and the fourth dichroic beam-splitting filter (3-1-2) are designed for 45 DEG incident light beams, and light with the wavelength smaller than the reflection band in the incident light beams is reflected in the direction perpendicular to the incident light by 90 DEG, and light in other wave bands is transmitted.
Further, the first dichroic beam-splitting filter (1-2-1) is a long-wave-pass dichroic beam-splitting filter, the reflection band is <480nm, and the transmission band is >510nm; the second dichroic beam-splitting filter (1-2-2) is a long-wave-pass dichroic beam-splitting filter, the reflection band is <400nm, and the transmission band is >440nm; the third dichroic beam-splitting filter (3-1-1) is a long-wave-pass dichroic beam-splitting filter, the reflection band is <400nm, and the transmission band is >440nm; the fourth dichroic beam-splitting filter (3-1-2) is a long-wave-pass dichroic beam-splitting filter, the reflection band <520nm, and the transmission band >560nm.
Further, the transmission band of the first long-wave pass filter (3-2-1) is >430nm; the transmission band of the second long-wave pass filter (3-2-2) is >370nm.
Further, the first photomultiplier (3-3-1) has a received spectral range >560nm; the receiving spectrum range of the second photomultiplier (3-3-2) is 430-520 nm; the third photomultiplier (3-3-3) has a receiving spectrum ranging from 370 to 400nm.
(III) beneficial effects
The invention provides a dual-wavelength laser-induced fluorescence light path system for monitoring bioaerosol, which comprises a laser unit, a detection cavity and a spectrum receiving unit which are sequentially connected. According to the invention, two kinds of laser with different wavelengths are used for exciting aerosol particles to generate fluorescence, so that the dual-wavelength fluorescence intensity spectrum of different aerosol particles can be obtained, and the particle size of the aerosol particles is measured by radiating the aerosol particles with independent red laser, so that the analysis of the particle size and the dual-wavelength fluorescence intensity spectrum can be used for distinguishing different aerosol particles, and the problem of difficult anti-interference existing in biological aerosol monitoring is solved; the light path system uses the light splitting filter to enable laser beams with different wavelengths to be coplanar and parallel, the light path in the detection cavity is simple, and compared with the complex cross focusing light path used by the existing commercial multi-wavelength LIF aerosol monitoring device, the light path system reduces the use of a light path focusing collimation device, simplifies the light path design and reduces the cost; the scattered light/fluorescence receiving light path is perpendicular to the laser irradiation light path, a dichroic beam-splitting filter and a wave-pass filter are used for separating and collecting a plurality of scattered light/fluorescence intensity spectrum signals, the excitation-receiving light path is concise, and the spectrum quality and the reliability of monitoring results are improved; the whole light path system is L-shaped, does not use a reverse fluorescence receiving light path, reduces the holes of the receiving light path on the detection cavity, effectively reduces the volume of the detection cavity, reduces the interference of stray light, and simultaneously improves the overall structural strength of the system.
The invention solves the problems that the existing LIF-based bioaerosol monitoring device is difficult to eliminate non-biological fluorescent particle interference and difficult to identify fluorescent particle types, and is beneficial to promoting innovation and development of bioaerosol monitoring technology and related equipment.
Drawings
FIG. 1 is a schematic diagram of a dual wavelength laser-induced fluorescence optical path system according to the present invention.
FIG. 2 is a schematic diagram of the laser unit and detection chamber structure in the present invention.
FIG. 3 is a schematic diagram of the structure of the spectrum receiving unit and the detection cavity in the present invention.
FIG. 4 is a fluorescence intensity spectrum of 650nm scattered light obtained by irradiating 1 μm fluorescent particle microsphere aerosol with a dual wavelength laser-induced fluorescence light path system in an embodiment of the present invention; in the figure: the abscissa is the scattered light signal intensity; the ordinate is the number of particles.
FIG. 5 is a graph showing the fluorescence intensity spectrum of two wavelengths obtained by irradiating a 1 μm fluorescent particle microsphere aerosol with a two-wavelength laser-induced fluorescence light path system in an embodiment of the present invention; in the figure: a-1 is a fluorescence intensity spectrum line generated by irradiating a 1 mu m fluorescent particle microsphere aerosol with 360nm laser; a-2 is a fluorescence intensity spectrum line generated by irradiating a 1 mu m fluorescent particle microsphere aerosol with 405nm laser; the abscissa is the scattered light signal intensity; the ordinate is the number of particles.
FIG. 6 is a fluorescence intensity spectrum of 650nm scattered light obtained by irradiating a Bacillus subtilis aerosol with a dual-wavelength laser-induced fluorescence light path system in an embodiment of the present invention; in the figure: the abscissa is the scattered light signal intensity; the ordinate is the number of particles.
FIG. 7 is a graph showing the fluorescence intensity spectrum of two wavelengths obtained by irradiating a Bacillus subtilis aerosol with a two-wavelength laser-induced fluorescence optical path system in an embodiment of the present invention; in the figure: b-1 is a fluorescence intensity spectrum line generated by 360nm laser irradiation of bacillus subtilis aerosol; b-2 is a fluorescence intensity spectrum line generated by irradiating bacillus subtilis aerosol with 405nm laser; the abscissa is the scattered light signal intensity; the ordinate is the number of particles.
FIG. 8 is a fluorescence intensity spectrum of 650nm scattered light obtained by irradiating a staphylococcus albus aerosol with a dual wavelength laser-induced fluorescence optical path system in an embodiment of the present invention; in the figure: the abscissa is the scattered light signal intensity; the ordinate is the number of particles.
FIG. 9 is a graph showing the fluorescence intensity spectrum of two wavelengths obtained by irradiating a staphylococcus albus aerosol with a dual wavelength laser-induced fluorescence optical path system in accordance with an embodiment of the present invention; in the figure: c-1 is a fluorescence intensity spectrum line generated by irradiating staphylococcus albus with laser of 360 nm; c-2 is a fluorescence intensity spectrum line generated by irradiating staphylococcus albus with 405nm laser; the abscissa is the scattered light signal intensity; the ordinate is the number of particles.
Detailed Description
To make the objects, contents and advantages of the present invention more apparent, the following detailed description of the present invention will be given with reference to the accompanying drawings and examples.
The invention provides a dual-wavelength laser-induced fluorescence optical path system for monitoring bioaerosol, which comprises a laser unit 1, a detection cavity 2 and a spectrum receiving unit 3 which are sequentially connected, as shown in figure 1; the aerosol particles contained in the aerosol air flow 2-3 in the detection cavity 2 are irradiated by the laser emitted by the laser unit 1 and generate scattered light and fluorescence, and the scattered light and the fluorescence are detected by the spectrum receiving unit 3 and subjected to subsequent data acquisition and photoelectric signal processing. The laser emission direction of the laser unit 1 is perpendicular to the scattered light and fluorescence receiving direction of the spectrum receiving unit 3.
As shown in fig. 2, the laser unit 1 includes a scattered light laser 1-1-1 outputting 650nm laser light, a first fluorescent laser 1-1-2 outputting 405nm laser light, a second fluorescent laser 1-1-3 outputting 360nm laser light, a first dichroic beam splitter filter 1-2-1, a second dichroic beam splitter filter 1-2-2, a first collimator 1-3-1, a second collimator 1-3-2, a third collimator 1-3-3, and a focusing mirror 1-4.
The first dichroic beam splitter filter 1-2-1 is a long-wave-pass dichroic beam splitter filter, the reflection band is less than 480nm, and the transmission band is more than 510nm; the second dichroic beam splitter 1-2-2 is a long-wave-pass dichroic beam splitter with reflection band <400nm and transmission band >440nm. The first dichroic beam-splitting filter 1-2-1 and the second dichroic beam-splitting filter 1-2-2 are designed for 45-degree incident light beams, and reflect light with the wavelength smaller than the reflection band in the incident light beams in the direction perpendicular to the incident light by 90 degrees, and light in other wave bands is transmitted.
The scattered light laser 1-1-1 is arranged in the laser unit 1, 650nm laser emitted by the scattered light laser 1-1 is collimated by the first collimating lens 1-3-1 to form parallel light, and then sequentially passes through the first dichroic beam-splitting filter 1-2-1, the second dichroic beam-splitting filter 1-2 and the focusing lens 1-4 to finally form a focusing light spot to irradiate the aerosol airflow 2-3 in the detection cavity 2.
The first fluorescent laser 1-1-2 and the second fluorescent laser 1-1-3 are arranged in the laser unit 1 at parallel intervals, 405nm laser emitted by the first fluorescent laser 1-1-2 is collimated by the second collimating mirror 1-3-2 and becomes parallel light, the parallel light is reflected by the first dichroic beam-splitting filter 1-2-1, and then the parallel light passes through the second dichroic beam-splitting filter 1-2-2 and the focusing mirror 1-4 to finally form an aerosol airflow 2-3 irradiated by a focusing light spot in the detection cavity 2; the 360nm laser emitted by the second fluorescent laser 1-1-3 is converted into parallel light through the third collimating lens 1-3-3, reflected by the second dichroic beam-splitting filter 1-2, and then passes through the focusing lens 1-4 to form a focusing light spot to irradiate the aerosol airflow 2-3 in the detection cavity 2.
Three laser beams emitted by the scattered light laser 1-1-1, the first fluorescent laser 1-1-2 and the second fluorescent laser 1-1-3 are adjusted by the first dichroic beam-splitting filter 1-2-1, the second dichroic beam-splitting filter 1-2-2 and the focusing mirror 1-4 to form three laser beams which are coplanar and parallel and irradiate into the detection cavity 2 at the same time, and the three laser beams form focusing light spots at the aerosol airflow 2-3 to excite aerosol particles to generate fluorescence and scattered light.
As shown in fig. 3, the detection chamber 2 comprises an aerosol sample injection nozzle 2-1, an aerosol exhaust port 2-2 and an extinction device 2-4; wherein, the aerosol sample injection nozzle 2-1 is arranged at the right center of the top of the detection cavity 2, and the aerosol exhaust port 2-2 is arranged at the right center of the bottom of the detection cavity 2 and vertically corresponds to the aerosol sample injection nozzle 2-1; the aerosol air flow 2-3 ejected by the aerosol sample injection nozzle 2-1 sequentially passes through three coplanar parallel lasers emitted by the laser unit 1, and scattered light and fluorescence are generated after aerosol particles are irradiated; the rest light of the laser emitted by the laser unit 1 after exciting the aerosol particles is absorbed by the extinction device 2-4, so that the interference of the excitation light on fluorescence is avoided; the aerosol air stream 2-3 is drawn out of the detection chamber 2 through the aerosol exhaust port 2-2.
The spectrum receiving unit 3 includes a third dichroic beam splitter 3-1-1, a fourth dichroic beam splitter 3-1-2, a first long-wave pass filter 3-2-1, a second long-wave pass filter 3-2-2, a first photomultiplier 3-3-1, a second photomultiplier 3-3-2, a third photomultiplier 3-3-3, and a collimator 3-4; wherein the third dichroic beam-splitting filter 3-1-1 is a long-wave-pass dichroic beam-splitting filter, the reflection band is <400nm, and the transmission band is >440nm; the fourth dichroic beam splitter 3-1-2 is a long-wave-pass dichroic beam splitter with reflection band <520nm and transmission band >560nm. The third dichroic beam-splitting filter 3-1-1 and the fourth dichroic beam-splitting filter 3-1-2 are designed for 45-degree incident light beams, and reflect light with the wavelength smaller than the reflection band in the incident light beams in the direction perpendicular to the incident light by 90 degrees, and light in other wave bands is transmitted. The transmission band of the first long-wave pass filter 3-2-1 is >430nm; the transmission band of the second long-wave pass filter 3-2-2 is more than 370nm; the receiving spectral range of the first photomultiplier tube 3-3-1 is >560nm; the receiving spectrum range of the second photomultiplier 3-3-2 is 430-520 nm; the third photomultiplier 3-3-3 has a received spectral range of 370-400 nm.
Scattered light generated by 650nm laser emitted by the scattered light laser 1-1-1 irradiating aerosol particles sequentially passes through the collimating lens 3-4, the third dichroic beam-splitting filter 3-1-1 and the fourth dichroic beam-splitting filter 3-1-2 and then is received by the first photomultiplier 3-1, and the scattered light signals of the aerosol particles are obtained after photoelectric conversion and data processing, and parameters such as particle size and the like of the aerosol particles are measured.
The fluorescence generated by the laser irradiation of 405nm emitted by the first fluorescent laser 1-1-2 on aerosol particles is collimated by the collimating mirror 3-4 and becomes parallel light, the collimated fluorescence irradiates on the third dichroic beam-splitting filter 3-1-1, the fluorescence with the wavelength larger than the transmission band of the third dichroic beam-splitting filter 3-1-1, namely >440nm, irradiates on the fourth dichroic beam-splitting filter 3-1-2 through the third dichroic beam-splitting filter 3-1-1, wherein the fluorescence with the wavelength smaller than the reflection band of the fourth dichroic beam-splitting filter 3-1-2, namely <520nm, is reflected on the first long-wavelength beam-splitting filter 3-2-1, the filtered fluorescence irradiates on the second photomultiplier 3-3-2 through the first long-wavelength beam-splitting filter 3-2-1 and is received, and 405nm excitation fluorescence intensity spectrum line is obtained through photoelectric conversion and data processing. The fluorescence generated by 360nm laser emitted by the second fluorescent laser 1-1-3 irradiating aerosol particles is collimated by the collimating lens 3-4 and becomes parallel light, the collimated fluorescence irradiates the third dichroic beam-splitting filter 3-1, the fluorescence with the wavelength smaller than the reflection band of the third dichroic beam-splitting filter 3-1-1, namely <400nm, is reflected to the second long-wavelength beam-splitting filter 3-2-2, and the fluorescence with the wavelength more than 370nm irradiates the third photomultiplier 3-3-3 through the second long-wavelength beam-splitting filter 3-2-2 and is received; fluorescence having a wavelength greater than the transmission band of the third dichroic spectroscopic filter 3-1-1, i.e., >440nm, is irradiated onto the fourth dichroic spectroscopic filter 3-1-2 through the third dichroic spectroscopic filter 3-1-1, wherein fluorescence having a wavelength less than the reflection band of the fourth dichroic spectroscopic filter 3-1-2, i.e., <520nm, is reflected onto the first long-wavelength pass filter 3-2-1, and fluorescence having a wavelength >430nm is irradiated onto the second photomultiplier 3-3-2 through the first long-wavelength pass filter 3-2-1 and received; namely, fluorescence of two wave bands of 370-400 nm and 440-520 nm, which are respectively generated by irradiating aerosol particles with 360nm laser emitted by the second fluorescent laser 1-1-3, is received, and 360nm excitation fluorescence intensity spectrum lines are obtained through photoelectric conversion and data processing, and the fluorescence intensity of the aerosol particles is comprehensively measured in combination with 405nm excitation fluorescence intensity spectrum lines.
Example 1
Preparing an aqueous solution of 1.0 mu m fluorescent particle microspheres, generating 1.0 mu m fluorescent particle microsphere aerosol by using a monodisperse aerosol generator, sequentially passing through three coplanar parallel lasers emitted by a laser unit 1 through 1 by using 1.0 mu m fluorescent particle microsphere aerosol airflow emitted by an aerosol injection nozzle 2-1, generating scattered light and fluorescence after the 1.0 mu m fluorescent particle microsphere is irradiated, detecting the scattered light and the fluorescence by a spectrum receiving unit 3, and carrying out subsequent data acquisition and photoelectric signal processing; the direction of the laser unit 1 irradiating laser light is perpendicular to the direction of the spectrum receiving unit 3 receiving scattered light and fluorescence; the rest light of the laser emitted by the laser unit 1 after exciting the aerosol particles is absorbed by the extinction device 2-4, so that the interference of the excitation light on fluorescence is avoided; the aerosol air stream 2-3 is drawn out of the detection chamber 2 through the aerosol exhaust port 2-2.
Scattered light generated by 650nm laser emitted by the scattered light laser 1-1-1 irradiating on the 1.0 μm fluorescent particle microsphere sequentially passes through the collimating lens 3-4, the third dichroic beam-splitting filter 3-1-1 and the fourth dichroic beam-splitting filter 3-1-2 and then is received by the first photomultiplier 3-3-1, and the scattered light intensity spectrum of the 1.0 μm fluorescent particle microsphere is obtained after photoelectric conversion and data processing, as shown in fig. 4.
The fluorescence generated by the laser light of 405nm emitted by the first fluorescent laser 1-1-2 and irradiated on the fluorescent particle microsphere of 1.0 mu m is irradiated on the third dichroic beam-splitting filter 3-1-1 through the collimating mirror 3-4, the fluorescence with the wavelength larger than the transmission band of the third dichroic beam-splitting filter 3-1-1 is irradiated on the fourth dichroic beam-splitting filter 3-1-2 through the third dichroic beam-splitting filter 3-1, wherein the fluorescence with the wavelength smaller than the reflection band of the fourth dichroic beam-splitting filter 3-1-2 is reflected on the first long-wave pass filter 3-2-1, the filtered fluorescence is irradiated on the second photomultiplier 3-3-2 and received, and the fluorescence with the wavelength smaller than the reflection band of the fourth dichroic beam-splitting filter 3-1-2 is subjected to photoelectric conversion and data processing to obtain the 405nm excitation fluorescence intensity spectrum of the fluorescent particle microsphere of 1.0 mu m, and the fluorescence intensity spectrum is shown in A-2 in figure 5.
The fluorescence generated by the 360nm laser emitted by the second fluorescent laser 1-1-3 irradiating on the 1.0 mu m fluorescent particle microsphere is irradiated on the third dichroic beam-splitting filter 3-1 through the collimating lens 3-4, the fluorescence with the wavelength smaller than the reflection band of the third dichroic beam-splitting filter 3-1 is reflected on the second long-wave pass filter 3-2, and the filtered fluorescence is irradiated on the third photomultiplier 3-3 through the second long-wave pass filter 3-2 and received; fluorescence having a wavelength greater than the transmission band of the third dichroic spectroscopic filter 3-1-1 is irradiated onto the fourth dichroic spectroscopic filter 3-1-2 through the third dichroic spectroscopic filter 3-1-1, wherein fluorescence having a wavelength less than the reflection band of the fourth dichroic spectroscopic filter 3-1-2 is reflected onto the first long-wavelength pass filter 3-2-1, and the filtered fluorescence is irradiated onto the second photomultiplier 3-3-2 through the first long-wavelength pass filter 3-2-1 and received; namely, the fluorescence of 370-400 nm and 440-520 nm, which are respectively generated by irradiating the 1.0 mu m fluorescent particle microsphere with 360nm laser emitted by the second fluorescent laser 1-1-3, is received, and the 360nm excitation fluorescence intensity spectrum line of the 1.0 mu m fluorescent particle microsphere is obtained through photoelectric conversion and data processing, wherein the fluorescence intensity spectrum line is shown as A-1 in figure 5.
Example 2
Preparing a solution of bacillus subtilis by using 1/16 diluted physiological saline, respectively generating aerosols by using a 3-hole claisen generator under 3L/min airflow, introducing the aerosols into a buffer cavity, and introducing diluted airflow into the buffer cavity for 60L/min to generate the bacillus subtilis aerosols with corresponding concentrations. Three beams of coplanar parallel laser emitted by the laser unit 1 sequentially pass through the bacillus subtilis aerosol airflow ejected by the aerosol injection nozzle 2-1, and after the bacillus subtilis is irradiated, scattered light and fluorescence are generated, and the scattered light and the fluorescence are detected by the spectrum receiving unit 3 and subjected to subsequent data acquisition and photoelectric signal processing; the direction of the laser unit 1 irradiating laser light is perpendicular to the direction of the spectrum receiving unit 3 receiving scattered light and fluorescence; the laser emitted by the laser unit 1 is absorbed by the extinction device 2-4 after exciting bacillus subtilis aerosol particles, so that the interference of excitation light on fluorescence is avoided; the aerosol air stream 2-3 is drawn out of the detection chamber 2 through the aerosol exhaust port 2-2.
The scattered light generated by 650nm laser emitted by the scattered light laser 1-1-1 irradiating the bacillus subtilis sequentially passes through the collimating lens 3-4, the third dichroic beam-splitting filter 3-1-1 and the fourth dichroic beam-splitting filter 3-1-2, and then is received by the first photomultiplier 3-3-1, and the scattered light intensity spectrum of the bacillus subtilis is obtained after photoelectric conversion and data processing, as shown in figure 6.
The fluorescence generated by the irradiation of 405nm laser emitted by the first fluorescent laser 1-1-2 on bacillus subtilis is irradiated onto the third dichroic beam-splitting filter 3-1-1 through the collimating lens 3-4, the fluorescence with the wavelength larger than that of the transmission band of the third dichroic beam-splitting filter 3-1-1 passes through the third dichroic beam-splitting filter 3-1 and irradiates onto the fourth dichroic beam-splitting filter 3-1-2, wherein the fluorescence with the wavelength smaller than that of the reflection band of the fourth dichroic beam-splitting filter 3-1-2 is reflected onto the first long-wave pass filter 3-2-1, the filtered fluorescence is irradiated onto the second photomultiplier 3-3-2 and received, and the fluorescence intensity spectrum line of the bacillus subtilis with the excitation of 405nm is obtained after photoelectric conversion and data processing, and the fluorescence intensity spectrum line is shown as B-2 in fig. 7.
The fluorescence generated by the 360nm laser emitted by the second fluorescent laser 1-1-3 irradiating on the bacillus subtilis is irradiated on the third dichroic beam-splitting filter 3-1 through the collimating lens 3-4, the fluorescence with the wavelength smaller than the reflection band of the third dichroic beam-splitting filter 3-1 is reflected on the second long-wave pass filter 3-2, and the filtered fluorescence is irradiated on the third photomultiplier 3-3 through the second long-wave pass filter 3-2 and received; fluorescence having a wavelength greater than the transmission band of the third dichroic spectroscopic filter 3-1-1 is irradiated onto the fourth dichroic spectroscopic filter 3-1-2 through the third dichroic spectroscopic filter 3-1-1, wherein fluorescence having a wavelength less than the reflection band of the fourth dichroic spectroscopic filter 3-1-2 is reflected onto the first long-wavelength pass filter 3-2-1, and the filtered fluorescence is irradiated onto the second photomultiplier 3-3-2 through the first long-wavelength pass filter 3-2-1 and received; namely, fluorescence which is generated by irradiating 360nm laser emitted by the second fluorescent laser 1-1-3 and is respectively generated by bacillus subtilis in 370-400 nm and 440-520 nm is received, and the fluorescence is subjected to photoelectric conversion and data processing to obtain a 360nm excitation fluorescence intensity spectrum line of the bacillus subtilis, wherein the fluorescence intensity spectrum line is shown as B-1 in figure 7.
Example 3
Preparing a staphylococcus albus solution by using 1/16 diluted physiological saline, respectively generating aerosols by using a 3-hole claisen generator under 3L/min airflow, introducing the aerosols into a buffer cavity, and introducing the diluted airflow into the buffer cavity for 60L/min to generate staphylococcus albus aerosols with corresponding concentrations. The staphylococcus albus aerosol airflow ejected through the aerosol injection nozzle 2-1 sequentially passes through three coplanar parallel lasers emitted by the laser unit 1, and bacillus subtilis is irradiated to generate scattered light and fluorescence, and the scattered light and the fluorescence are detected by the spectrum receiving unit 3 and subjected to subsequent data acquisition and photoelectric signal processing; the direction of the laser unit 1 irradiating laser light is perpendicular to the direction of the spectrum receiving unit 3 receiving scattered light and fluorescence; the laser emitted by the laser unit 1 is absorbed by the extinction device 2-4 after exciting bacillus subtilis aerosol particles, so that the interference of excitation light on fluorescence is avoided; the aerosol air stream 2-3 is drawn out of the detection chamber 2 through the aerosol exhaust port 2-2.
Scattered light generated by 650nm laser emitted by the scattered light laser 1-1-1 irradiating the staphylococcus albus sequentially passes through the collimating lens 3-4, the third dichroic beam-splitting filter 3-1-1 and the fourth dichroic beam-splitting filter 3-1-2 and then is received by the first photomultiplier 3-1, and the scattered light intensity spectrum of the staphylococcus albus is obtained after photoelectric conversion and data processing, as shown in fig. 8.
The fluorescence generated by the irradiation of 405nm laser emitted by the first fluorescent laser 1-1-2 on staphylococcus is irradiated onto the third dichroic beam-splitting filter 3-1-1 through the collimating lens 3-4, the fluorescence with the wavelength larger than that of the transmission band of the third dichroic beam-splitting filter 3-1-1 passes through the third dichroic beam-splitting filter 3-1 and irradiates onto the fourth dichroic beam-splitting filter 3-1-2, wherein the fluorescence with the wavelength smaller than that of the reflection band of the fourth dichroic beam-splitting filter 3-1-2 is reflected onto the first long-wave pass filter 3-2-1, the filtered fluorescence irradiates onto the second photomultiplier 3-3-2 and is received, and the fluorescence intensity spectrum line of the staphylococcus with 405nm excitation is obtained through photoelectric conversion and data processing, and the fluorescence intensity spectrum line is shown as C-2 in figure 9.
The fluorescence generated by the irradiation of 360nm laser emitted by the second fluorescent laser 1-1-3 on staphylococcus albus is irradiated to the third dichroic beam-splitting filter 3-1 through the collimating lens 3-4, the fluorescence with the wavelength smaller than the reflection band of the third dichroic beam-splitting filter 3-1-1 is reflected to the second long-wave pass filter 3-2, and the filtered fluorescence is irradiated to the third photomultiplier 3-3 through the second long-wave pass filter 3-2 and received; fluorescence having a wavelength greater than the transmission band of the third dichroic spectroscopic filter 3-1-1 is irradiated onto the fourth dichroic spectroscopic filter 3-1-2 through the third dichroic spectroscopic filter 3-1-1, wherein fluorescence having a wavelength less than the reflection band of the fourth dichroic spectroscopic filter 3-1-2 is reflected onto the first long-wavelength pass filter 3-2-1, and the filtered fluorescence is irradiated onto the second photomultiplier 3-3-2 through the first long-wavelength pass filter 3-2-1 and received; namely, fluorescence of two wave bands of 370-400 nm and 440-520 nm, which are respectively generated by irradiating staphylococcus with 360nm laser emitted by the second fluorescent laser 1-1-3, is received, and 360nm excitation fluorescence intensity spectrum of staphylococcus is obtained through photoelectric conversion and data processing, wherein the fluorescence intensity spectrum is shown as C-1 in figure 9.
As can be seen from FIGS. 4, 6 and 8, 1 μm fluorescent particle microspheres, bacillus subtilis and Staphylococcus albus were all irradiated with 650nm laser light to generate scattered light, and the signal intensities of the scattered light of the 3 substances were significantly different. The aerosol concentration of different substances can be obtained by analyzing and calculating the scattered light intensity spectrum. By analyzing the images in fig. 5, 7 and 9, it can be found that the dual-wavelength fluorescence intensity spectrum of 1 μm fluorescent particle microsphere, bacillus subtilis and staphylococcus albus respectively contains the fluorescence intensity spectrum generated after the irradiation of 360nm laser and 405nm laser, and the peak central lines of the dual-wavelength fluorescence intensity spectrum of the three substances are obviously different. As shown in the following table, by analyzing the characteristic parameters of the scattered light intensity, the peak center line of the 360nm excitation fluorescence intensity spectrum, the peak center line of the 405nm excitation fluorescence intensity spectrum and the like of the three substances, the primary distinction of the aerosols of the three substances can be realized.
The light path system comprises 1 scattered light laser and 2 fluorescent lasers, 3 laser beams are modulated into coplanar parallel radiation by using a combination of a dichroic beam-splitting filter and a focusing mirror and enter a detection cavity 2, a scattered light/fluorescent receiving light path is perpendicular to a laser radiation light path, and a plurality of scattered light/fluorescent intensity spectrum signals are separated and collected by using the dichroic beam-splitting filter and a wave-pass filter. The light path system singly uses red light laser emitted by the scattered light laser to irradiate aerosol particles to generate scattered light so as to measure the particle sizes of different aerosols, and two lasers with different wavelengths excite the aerosol particles to generate fluorescence so as to obtain the dual-wavelength fluorescence intensity spectrum of the different aerosol particles. The dual-wavelength fluorescence intensity spectrum of each aerosol comprises a fluorescence intensity spectrum line generated after 360nm laser and 405nm laser irradiation, the aerosols are initially classified by analyzing and calculating the dual-wavelength fluorescence intensity spectrum of the aerosols of different substances, and unless the bioluminescence particles interfere, so that the detection efficiency and accuracy are improved. Compared with a complex cross focusing optical path of a commercial multi-wavelength LIF aerosol analyzer, the dual-wavelength laser-induced fluorescence optical path system for monitoring the biological aerosol is integrally L-shaped, so that the use of an optical path focusing collimation device is reduced, an excitation-receiving optical path is concise, the cost is reduced, the spectral quality and the reliability of a monitoring result are improved, the anti-interference performance of detection is enhanced, the preliminary classification of the aerosol is realized, and technical support is provided for innovation and development of a biological aerosol monitoring technology and related equipment.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.
Claims (10)
1. The dual-wavelength laser-induced fluorescence optical path system for monitoring the bioaerosol is characterized by comprising a laser unit (1), a detection cavity (2) and a spectrum receiving unit (3) which are connected in sequence; the aerosol particles contained in the aerosol airflow (2-3) in the detection cavity (2) are irradiated by laser emitted by the laser unit (1) and generate scattered light and fluorescence, and the scattered light and the fluorescence are detected by the spectrum receiving unit (3) and subjected to subsequent data acquisition and photoelectric signal processing.
2. The dual wavelength laser-induced fluorescence optical path system according to claim 1, wherein the laser light emission direction of the laser unit (1) is perpendicular to the scattered light and fluorescence receiving direction of the spectrum receiving unit (3).
3. The dual wavelength laser-induced fluorescence light path system according to claim 1, wherein the laser unit (1) comprises a scattered light laser (1-1-1), a first fluorescence laser (1-1-2), a second fluorescence laser (1-1-3), a first dichroic beam splitter filter (1-2-1), a second dichroic beam splitter filter (1-2-2), a first collimator (1-3-1), a second collimator (1-3-2), a third collimator (1-3-3) and a focusing mirror (1-4); wherein, the liquid crystal display device comprises a liquid crystal display device,
the scattered light laser (1-1-1) is arranged in the laser unit (1), and laser emitted by the scattered light laser (1-1-1) sequentially irradiates into the detection cavity (2) through the first collimating mirror (1-3-1), the first dichroic beam-splitting filter (1-2-1), the second dichroic beam-splitting filter (1-2-2) and the focusing mirror (1-4);
the first fluorescent lasers (1-1-2) and the second fluorescent lasers (1-1-3) are arranged in the laser unit (1) at parallel intervals, and laser emitted by the first fluorescent lasers (1-1-2) is reflected by the first dichroic beam-splitting filter (1-2-1) after passing through the second collimating mirror (1-3-2) and then irradiates into the detection cavity (2) through the second dichroic beam-splitting filter (1-2-2) and the focusing mirror (1-4); the laser emitted by the second fluorescent laser (1-1-3) is reflected by the second dichroic beam-splitting filter (1-2-2) after passing through the third collimating mirror (1-3-3), and then is irradiated into the detection cavity (2) through the focusing mirror (1-4);
three laser beams emitted by the scattered light laser (1-1-1), the first fluorescent laser (1-1-2) and the second fluorescent laser (1-1-3) are adjusted by the first dichroic beam-splitting filter (1-2-1), the second dichroic beam-splitting filter (1-2-2) and the focusing mirror (1-4) to form three laser beams which are coplanar and parallel and irradiate into the detection cavity (2) at the same time, and the three laser beams form focusing light spots at the aerosol airflow (2-3) to excite aerosol particles to generate fluorescence and scattered light.
4. A dual wavelength laser-induced fluorescence optical path system as claimed in claim 3, characterized in that the detection chamber (2) comprises an aerosol injection nozzle (2-1), an aerosol exhaust port (2-2) and a matting device (2-4); the aerosol sampling nozzle (2-1) is arranged at the right center of the top of the detection cavity (2), and the aerosol exhaust port (2-2) is arranged at the right center of the bottom of the detection cavity (2) and vertically corresponds to the aerosol sampling nozzle (2-1); the aerosol airflow (2-3) ejected by the aerosol sample injection nozzle (2-1) sequentially passes through three coplanar parallel lasers emitted by the laser unit (1), and scattered light and fluorescence are generated after aerosol particles are irradiated; the laser emitted by the laser unit (1) is absorbed by the extinction device (2-4) after the aerosol particles are excited, so that the interference of excitation light on fluorescence is avoided; the aerosol air flow (2-3) is pumped out of the detection cavity (2) through the aerosol exhaust port (2-2).
5. The dual wavelength laser-induced fluorescence optical path system according to claim 4, wherein the spectrum receiving unit (3) includes a third dichroic beam splitter (3-1-1), a fourth dichroic beam splitter (3-1-2), a first long-pass filter (3-2-1), a second long-pass filter (3-2-2), a first photomultiplier (3-3-1), a second photomultiplier (3-3-2), a third photomultiplier (3-3-3), and a collimator lens (3-4); wherein, the liquid crystal display device comprises a liquid crystal display device,
scattered light generated by laser emitted by the scattered light laser (1-1-1) irradiating aerosol particles sequentially passes through a collimating lens (3-4), a third dichroic beam-splitting filter (3-1-1) and a fourth dichroic beam-splitting filter (3-1-2) and then is received by a first photomultiplier (3-3-1), and a scattered light signal of the aerosol particles is obtained after photoelectric conversion and data processing;
the fluorescence generated by the laser emitted by the first fluorescent laser (1-1-2) irradiating the aerosol particles is irradiated to the third dichroic beam-splitting filter (3-1-1) through the collimating mirror (3-4), the fluorescence with the wavelength larger than that of the transmission band of the third dichroic beam-splitting filter (3-1-1) passes through the third dichroic beam-splitting filter (3-1) and irradiates to the fourth dichroic beam-splitting filter (3-1-2), wherein the fluorescence with the wavelength smaller than that of the reflection band of the fourth dichroic beam-splitting filter (3-1-2) is reflected to the first long-wavelength beam-splitting filter (3-2-1), the filtered fluorescence is irradiated to the second photomultiplier (3-3-2) through the first long-wavelength beam-splitting filter (3-2-1) and received, and a fluorescence signal generated by the laser emitted by the first fluorescent laser (1-1-2) irradiating the aerosol particles is obtained after photoelectric conversion and data processing;
the fluorescence generated by the laser emitted by the second fluorescent laser (1-1-3) irradiating aerosol particles is irradiated to the third dichroic beam-splitting filter (3-1-1) through the collimating mirror (3-4), the fluorescence with the wavelength smaller than the reflection band of the third dichroic beam-splitting filter (3-1-1) is reflected to the second long-wave pass filter (3-2), and the filtered fluorescence is irradiated to the third photomultiplier (3-3-3) through the second long-wave pass filter (3-2) and received; fluorescence having a wavelength greater than that of the transmission band of the third dichroic beam splitter filter (3-1-1) is irradiated onto the fourth dichroic beam splitter filter (3-1-2) through the third dichroic beam splitter filter (3-1-1), wherein fluorescence having a wavelength less than that of the reflection band of the fourth dichroic beam splitter filter (3-1-2) is reflected onto the first long-wavelength pass filter (3-2-1), and the filtered fluorescence is irradiated onto the second photomultiplier (3-3-2) through the first long-wavelength pass filter (3-2-1) and received; and obtaining a fluorescence signal generated by irradiating aerosol particles with laser light emitted by the second fluorescence laser (1-1-3) after photoelectric conversion and data processing.
6. A dual wavelength laser-induced fluorescence optical path system according to claim 3, wherein the scattered light laser (1-1-1) emits laser light having a wavelength of 650nm; the wavelength of laser emitted by the first fluorescent laser (1-1-2) is 405nm; the laser wavelength of the second fluorescent laser (1-1-3) is 360nm.
7. The dual wavelength laser induced fluorescence optical path system of claim 5, wherein the first dichroic filter (1-2-1), the second dichroic filter (1-2-2), the third dichroic filter (3-1-1), and the fourth dichroic filter (3-1-2) are designed for an incident light beam of 45 ° and reflect light of a wavelength smaller than a reflection band in the incident light beam in a direction perpendicular to the incident light by 90 °, and light of other wavelength bands is transmitted.
8. The dual wavelength laser-induced fluorescence optical path system of claim 5, wherein the first dichroic beam splitter (1-2-1) is a long-wave pass dichroic beam splitter, reflection band <480nm, transmission band >510nm; the second dichroic beam-splitting filter (1-2-2) is a long-wave-pass dichroic beam-splitting filter, the reflection band is <400nm, and the transmission band is >440nm; the third dichroic beam-splitting filter (3-1-1) is a long-wave-pass dichroic beam-splitting filter, the reflection band is <400nm, and the transmission band is >440nm; the fourth dichroic beam-splitting filter (3-1-2) is a long-wave-pass dichroic beam-splitting filter, and the reflection band is <520nm and the transmission band is >560nm.
9. The dual wavelength laser-induced fluorescence optical path system of claim 5, wherein the transmission band of the first long-wave pass filter (3-2-1) is >430nm; the transmission band of the second long-wave pass filter (3-2-2) is >370nm.
10. The dual wavelength laser-induced fluorescence optical path system of claim 5, wherein the first photomultiplier tube (3-3-1) has a reception spectral range >560nm; the receiving spectrum range of the second photomultiplier (3-3-2) is 430-520 nm; the third photomultiplier (3-3-3) has a receiving spectrum ranging from 370 to 400nm.
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